If you write in a category, you write knowing there’s a framework, there are reader expectations.
Something happened in the United States in the early 1980s. Obesity had already been on the rise in the United States and throughout the world, but in the early 1980s, obesity rates began to accelerate as never before. Since that time, we have been getting fatter at an alarming rate, and the upward trend in obesity rates does not show any signs of slowing. Besides the aesthetic frustrations that come with obesity, there are also countless health problems that threaten not only to cost billions of dollars to treat, but also to decrease our collective and individual enjoyment of life.
Leading diabetes and obesity researchers are racing against the clock, trying to figure out how to stop the rapidly progressing obesity epidemic. The researchers know what causes obesity, and how to create weight loss in controlled environments. What remains unclear, however, is the best way to treat obesity in real life, and on a grand scale. In this chapter we will explore the basic weight loss concepts that researchers agree upon. We will also consider why some diets succeed while others fail, and I will provide you with a weight loss framework in which to view the rest of the information in this book.
Are you wondering about the Nora Roberts quote? I include it because I understand that I am writing in the diet genre, a genre that is admittedly bloated itself. You are probably wondering if this is another low carbohydrate diet, or another low fat diet, as these are currently the dominant dietary frameworks. The Decaf Diet is neither of these. Instead of focusing on a particular food list of allowed or disallowed foods, I focus only on the role that caffeine plays in overeating, and how to overcome caffeine’s fattening effects.
My framework is that of overeating being the cause both of weight gain and the diseases that are associated with weight gain. I view caffeine consumption in terms of its effects on overeating, and it is from that vantage point that I make the recommendations in this book. Before moving on to the particulars of caffeine’s impact on our waistlines, let’s discuss some dietary frameworks, become familiar with the basics of these frameworks, and in this way begin our discussion of caffeine with a background understanding of what it takes to lose weight and keep it off.
The only valid, inclusive framework with which to view weight gain and weight loss is that of energy balance. The two energy balance variables that control weight gain and weight loss are energy intake and energy expenditure. Energy intake is food intake, and energy expenditure is the body’s use of food energy throughout the day. Energy expenditure includes the body’s burning of energy both while at rest and while engaged in physical activity. When energy intake exceeds energy expenditure for a given period of time, we enter positive energy balance, and weight gain occurs. When energy expenditure exceeds energy intake for a given period of time, we enter negative energy balance, and weight loss occurs. Medical professionals and obesity researchers agree that energy balance determines whether we gain weight or lose it, and that obesity can be treated only by reducing energy intake (eating less) or increasing energy expenditure (exercising more).
In the context of diet, energy is often measured in calories. A calorie is a unit of energy that we use to measure the energy we receive from food and that we expend in our daily activities. One calorie is the amount of energy necessary to increase the temperature of one liter of water by one degree centigrade, at sea level. By decreasing food intake enough, or by increasing physical activity enough, an individual can reach the point of negative calorie balance (negative energy balance), where energy intake is less than energy expenditure in a given period of time. Once our hypothetical dieter reaches and maintains negative calorie balance for a long enough period of time, he will lose weight. Negative calorie balance can be described as undereating, and positive energy balance can be described as overeating.
There are several ways to achieve negative calorie balance. The dieter can decrease calorie intake while keeping calories burned constant; or increase calories burned while keeping calorie intake constant; or decrease calorie intake and increase calories burned simultaneously. Those are the only “weighs” to do it. Sorry about that, I am a sucker for bad puns. But that is the formula for weight loss. The formula is simple enough, but sustaining negative calorie balance is more difficult in practice than it is on paper. Most dieters fail to lose weight, and when they do succeed they often find themselves gaining back all of the weight they lost.
While researchers and diet experts agree that decreasing food intake and increasing physical activity are the keys to weight loss, they disagree on which of these two strategies should receive the most attention from dieters seeking lasting weight loss. Some researchers contend that adding regular exercise to our lives is the answer. Others contend that any weight loss effort can succeed only through diet, because our diet is the most modifiable part of the energy balance equation, whereas modern sedentary life makes regular exercise impractical.
Yet other researchers point to the increase in food intake and simultaneous decrease in physical activity that took place in the last century and argue that any effective weight loss plan must both decrease food intake and increase physical activity. All of these approaches have value, and the viability of each approach depends on the circumstances of individual dieters. Some have time for exercise, others do not. For those who can not exercise and who must sit at work to earn a living, a greater burden necessarily falls on the food intake half of the calorie equation.
A number of different factors are responsible for the common inability to achieve negative calorie balance and sustain it. First, we can look at North American culture, with its emphasis on large portion sizes and calorie-dense eating at fast food restaurants. North American culture is rapidly spreading throughout the world, and the fast food culture is no longer a local phenomenon. Second, we can try to explain why we overeat from a biological perspective. This explanation focuses on how our food choices, hormones, and environments affect our feelings of satiety (feelings of being full) and our desire to overeat.
Our caffeine consumption makes negative calorie balance very difficult to achieve and maintain. As I will explain in detail in the upcoming chapters, caffeine contributes significantly to overeating in a number of different ways. Since I do not expect to change the cultural aspects of American life that contribute to overeating through this book, I will focus on how to remove the biological impediments to achieving negative calorie balance, and the biological impediments to staying out of positive calorie balance. In other words, the recommendations in this book will help you reduce your food intake and achieve negative calorie balance with little effort, simply by modifying your caffeine intake.
Hormonal factors and other non-energy balance variables are only relevant to the weight loss discussion when they affect energy balance by affecting food intake, energy expenditure, or both. There are a great many different weight loss diets. Some focus on calories, others focus on macronutrient ratios (the proportions of dietary fat, protein, and carbohydrate), and yet others focus on hormonal balance. All of these factors – calories, macronutrient ratios, and hormonal balance – are interrelated such that they are inseparable.
Why are there so many diets? I think it is in part because people are always searching for causal relationships to explain the physical world, and there are a great many valid causal relationships that exist, some that are known and others that remain undiscovered. However, it often happens that hormonal balance or macronutrient balance are blamed out of context. Hormonal balance and macronutrient balance are relevant only to the extent that they have an impact on the body’s overall energy balance. Hormones can not make you fat, unless they can increase your food intake and/or decrease your energy expenditure significantly enough to create a positive energy balance.
Diet writers sometimes observe two phenomena that present themselves simultaneously, and in trying to establish a causal link between the two, forget about energy balance completely. Even if energy balance were not the most important aspect of changing one’s body fat levels, which it is, just because two events occur simultaneously, it does not necessarily follow that one causes the other. On the contrary, both phenomena may have one common explanatory cause, or they may have two or more distinct explanatory causes.
To be slightly less abstract, let’s say we are talking about obesity and high levels of hormone X and a high intake of macronutrient Y, which present themselves simultaneously most of the time. The way people usually react to this scenario is by trying to find ways that explain how high levels of hormone X and a high intake of macronutrient Y cause obesity, or how obesity causes high levels of hormone X. Where we sometimes go wrong is in forgetting that another distinct cause, such as overeating (positive energy balance), may be responsible for obesity and high levels of hormone X and a high intake of macronutrient Y. If we begin to believe that overeating is the initial cause of both obesity and high levels of hormone X and a high intake of macronutrient Y, the next point of error is to forget that obesity, hormone X, and a high intake of macronutrient Y, once present, may themselves contribute to overeating, their initial common cause, leading to a self-perpetuating cycle.
In our hypothetical scenario, overeating leads to obesity, high levels of hormone X, and a high intake of macronutrient Y. Hormone X and a high intake of macronutrient Y in turn increase our overeating behavior by making us have food cravings for specific foods. Overeating may also cause high levels of hormone Z, which rather than creating cravings, decreases our ability to feel full, and contributes to overeating indirectly. What am I trying to say with this alphabet soup? My point is that what and how much we eat affect our hormones, and our hormones also affect what and how much we eat. To blame hormones alone, or to blame macronutrients alone, is to paint an incomplete picture, and biology does not allow for this kind of oversimplification.
This notion of interrelationships will crystallize as we continue our discussion. For now, let’s continue by deconstructing popular notions about metabolism and the most popular dietary frameworks, with an aim at understanding the difference between dietary success and failure. We will then explore how caffeine helps to put most weight loss efforts in the failure category.
Metabolism is one of the favorite buzzwords of the diet and fitness communities. I’ll admit it, I like it too. It’s a sexy term. In the mainstream parlance metabolism refers to an individual’s rate of fat-burning while at rest, as distinguished from that individual’s rate of fat-burning while engaged in physical activity. Metabolism refers to the energy expenditure that takes place while we are lounging about, reading the paper, watching television, and so forth. We are all told that as we get older, our bodies begin to slow down and burn calories at a slower rate, thus making it more and more difficult to stay lean. Many people even have their own theories about the precise age at which our metabolisms slow down, the point from which “it’s all downhill.”
A friend of mine insists that 25 is the magical age when the body begins to shut down and everything starts to break and shift into low gear. Of course, it is impossible to pinpoint a specific age that can be generalized among all people, but most of us come to accept that a slowing metabolism is an inevitable part of getting older, as is the fat gain that invariably accompanies aging. But to what extent can we really blame our metabolisms for making us gain weight? Do those of us who are prone to weight gain have slow metabolisms when compared to those of us who stay lean?
Before we answer this question, let’s explore the origins of the idea that a slow metabolism causes weight gain. With vehemence and vitriol, many contemporary diet writers proclaim that calories don’t matter. Why is “calories don’t matter” the clarion call of some diet promoters, most notably promoters of the low carbohydrate diet, and to some extent of the low fat, whole foods, and vegan diets? This anti-calorie propaganda originated when some dieters began to claim that they could not lose weight no matter how little they ate or how much they exercised. These problem dieters were supposedly unable to lose weight while on low calorie diets, but then eventually were successful on a low carbohydrate or other diet that promises hormonal benefits that are allegedly more important than calorie balance. Is there in fact such a dieter to whom the energy balance equation does not apply? As you can suspect from my tone, the answer is no.
There is a popular mainstream belief that some individuals can gain weight or survive with almost no food, and that obese individuals eat no more, or even less, than lean individuals. Due to the absence of an accurate way to measure an individual’s energy expenditure before the 1980s, this belief has prevailed for a long time, and is still common today.2 Its origin can be traced back to the first dieters who showed up at the doorsteps of doctors and researchers, claiming that they eat very little, and yet can not lose weight or even continue to gain weight. These dieters maintained that they ate almost nothing, exercised, and their weight still would not budge. So the doctors and researchers studied these dieters, and in the absence of an accurate way to measure how much the dieters ate and how much energy they expended during the day, the doctors and researchers were forced to rely on the dieters’ own reports of their daily food intake and activity levels. The result is that much obesity research was done by researchers relying on the self-reported food intakes of dieters.
A reliance on the self-reporting of food intake led to the proliferation of the “calories don’t count” phenomenon that we still see today, lending support to the notion that a slow metabolism causes weight gain. Self-reporting is notoriously inaccurate and unreliable, but there is so much of this erroneous data that many diet writers have relied on and continue to rely on self-reported accounts of food intake.3 The researchers who have relied on this inaccurate data have concluded that the overweight and obese eat less than the lean, that the amount of food eaten has no relation to body weight, and therefore that overeating has nothing to do with the obesity epidemic.4
The following quote from a leading obesity researcher sums it up nicely: “[t]he unlikely possibility that the laws of thermodynamics need reconsideration or that humans can generate energy by photosynthesis can probably be discounted.”5 This quote is made funnier by the fact that some individuals claim they can survive by feeding on sunlight, in the absence of food. Putting these notions to rest once and for all, the doubly labeled water method, which was perfected for use in humans in the early 1980s, allows researchers to accurately measure an individual’s energy expenditure.
Researchers employ the doubly labeled water method by administering water to subjects in which the hydrogen and oxygen have been replaced by less common isotopes of these elements (this water is said to be traced, or labeled). The researchers are then able to accurately determine the subjects’ metabolic rates by taking saliva, blood, and urine samples, measuring the rate at which subjects eliminate the labeled water.
This measurement technique finally enabled researchers to examine the hypothesis that overweight individuals eat less than lean individuals and yet remain overweight. Unsurprisingly, this hypothesis was found not to hold water. Studies using the doubly labeled water method described above have highlighted the inaccuracy of self-reported food logs, and have demonstrated that the inaccuracy of self-reported food intake increases with an individual’s weight.6 Dieters frequently underreport their daily food intakes, even when researchers thoroughly train these dieters to accurately keep food logs.7 Instead of recording their actual food intakes, dieters tend to record food intakes that are much lower, and the heavier a dieter is, the worse is his degree of underreporting.
In one study that examined the disparity between self-reported intakes and actual intakes as measured by the doubly labeled water method, the participants underestimated their food intakes by an average of more than 1000 calories per day.8 In some cases the participants, whom researchers thoroughly instructed on how to take accurate records, were self-reporting only half of their actual food intakes! Overweight and obese individuals do in fact have higher food intakes than lean individuals, and at this point in our discussion this should be no surprise.9 A number of studies have shown that the degree of underreporting is usually less severe than 50%, and ranges from 20-40% less than actual energy intake, which is still a considerable level of underreporting.10
What are some causes of the underreporting phenomenon? One of the main causes is that most of us tend to fill out food logs in ways that show us in a favorable light, both to portray a positive image to others and to ourselves.11 Whether we do this consciously or subconsciously, inaccurate self-reporting can be viewed as a self-protective technique, but it is disadvantageous when weight loss is our ultimate goal. Another significant cause of underreporting is the mislabeling of foods. The textbook weight of some foods (found in calorie references for dieters) is often far below the weight of these foods in real life, and some foods that are marketed as “diet” foods often contain many more calories than their labels state.12 This is true mostly for local and regional “diet” foods, as nationally promoted “diet” foods are more careful with their labeling.
Keeping accurate food logs and counting calories is difficult to do accurately outside of the laboratory, so it has led to the belief that calories are not important. It’s not that calories don’t count, it’s that we can’t and don’t have the time or energy to count calories. Diets work best when they don’t require their participants to count calories, but create satiety, which results in an automatic down-regulation of food intake. Moreover, feelings of hunger and satiety are not necessarily functions of calorie intake. The ideal way to lose weight is to reduce food cravings so that food intake automatically decreases, and simultaneously increase the body’s metabolic rate.
As we’ll soon see, manipulating our caffeine intakes can have a profound impact on our feelings of satiety, and a significant impact on our resting energy expenditure. The bottom line is that self-recorded food logs are not accurate, and now that we have accurate and reliable methods for measuring energy intake and energy expenditure, we can return to the meaningful framework of energy balance and seek our weight loss goals with the aid of logic and objectivity.
Most of us who gain weight and find it difficult to lose do not suffer from a “slow metabolism.” The doubly labeled water method finally enabled researchers to examine the hypothesis that fat gain is the result of having a slow metabolism, and studies using this method do not support the old and popular notion that weight gain and obesity are caused by a slow metabolism.13 These studies did not find that overweight people have slow metabolisms.
On the contrary, the research demonstrates that many overweight and obese individuals have metabolic rates faster than those of lean individuals.14 Overweight and obese individuals actually have a greater average energy expenditure than lean individuals, due to the increase in energy-consuming muscle mass that comes with weight gain and the increased energy demand on the body to support extra weight. Furthermore, research also does not support the popular notion that undereating and low calorie diets slow an individual’s metabolism, making weight loss difficult or impossible.15
The notion of a “slow metabolism” as the cause of weight gain is appealing but dangerous. Believing the slow metabolism hype lets us shift the responsibility for our weight gain away from ourselves and onto our supposedly malfunctioning bodies. It leads to thinking that “I am not overweight because of factors that I can control, such as my food intake and level of physical activity, but because of my treacherous metabolism.”
The danger in this kind of thinking, aside from its falsity, is that we give up control of our weight problems to the somewhat abstract notion of metabolism, and as a result we can feel justified in inaction. If our metabolisms are “slow,” we are powerless in the struggle to lose weight, so why try? The “slow metabolism” idea breeds resignation and inaction, and in many cases is an excuse to avoid changing our eating and exercise habits.
Aside from the finding that a slow metabolism is not the cause of weight gain, there is another point you should take away from the above studies. That is the finding that your rate of fat burning while at rest is affected most significantly by the amount of fat-free mass in your body, so maintaining high levels of muscle mass will give you some metabolic advantage, however small.16
While a slow metabolism does not make us fat, it may still be desirable to aim for the slight metabolic boost that increased muscle mass provides, if we can experience this boost in conjunction with a reduced food intake. That being said, your rate of fat-burning at rest is not as important for maintaining leanness as is your level of physical activity.17 An individual’s rate of fat burning while the body is at rest has very little impact on that individual’s propensity to gain weight. Instead, the most important variable that affects an individual’s total energy expenditure is the amount of physical activity that individual performs. Regular exercise makes it more likely that the weight loss you experience will be permanent, and the common post-diet weight regain will not occur.18
While it is rare for an individual to be suffering from a slow metabolism, it does happen in certain cases, for example, it may occur in individuals who were previously treated for an overactive thyroid and who are currently on certain medications.19 In cases like this, it is not unusual for the individual metabolic rate to be approximately 25% below average.
Although having a slow metabolism like this is rare, I want to cover all of the bases so I will focus on increasing your resting metabolic rate as well as your level of physical activity, so we can address the energy expenditure part of the equation from all the angles. While the metabolic boost you receive from carrying some extra muscle is modest, every little bit counts, and we’ll discuss how to increase and maintain your muscle mass in several of the upcoming chapters. As you’ll soon see, caffeine consumption has a direct effect on the amount of muscle mass you carry (it’s not a positive one).
Since we are talking about metabolism and energy expenditure, this is as good a time as any to introduce the thermic effect of food. The thermic effect of food is the amount of energy that the body must expend in digesting food to break it down into substances that it can use for growth, repair, maintenance, and energy. The three macronutrients, carbohydrates, fat, and protein, have different thermic effects. Each of these macronutrients takes a different amount of energy to digest. The thermic effect of protein is approximately 20-35% of ingested calories; the thermic effect of carbohydrates is approximately 15-25% of ingested calories; and the thermic effect of fat is approximately 5-10% of ingested calories.20
The practical application of this information is the conclusion that fat is the most efficiently stored macronutrient, followed by carbohydrate, and then protein. By most efficiently stored, I mean that our bodies can get the most energy out of this macronutrient to store as fat, so if weight loss is your concern, you want to avoid foods that the body stores with the greatest efficiency. The overfeeding of protein results in 65-80% of excess energy being stored; overfeeding of carbohydrate results in 75-85% of the excess energy being stored; and overfeeding of fat results in 90-95% of the excess energy being stored. On average, if we ignore the differences among macronutrients, the thermic effect of food is about 10% of the food’s calorie content.21
Let’s illustrate the thermic effect with the following example. If we eat 25 grams of protein, which is 100 calories on paper, our bodies will be able to extract about 65-80 calories of usable energy from this serving of protein. If we eat 25 grams of carbohydrate, which is also 100 calories, our bodies will be able to extract about 75-85 calories of usable energy from this serving of carbohydrate.
If we eat approximately 11 grams of fat, the equivalent of 100 calories, our bodies will be able to extract 90-95 calories of usable energy from this serving of fat. Fat requires the least amount of energy to digest, protein requires the most, and carbohydrate is in the middle. So if our goal is to increase our energy expenditure in digestion, our meals should consist mainly of protein. I mention this for purposes of illustration, and not as a recommendation to adopt a high protein diet.
You probably noticed that 25 grams of protein or carbohydrate both contain 100 calories, but only 11 grams of fat contain 100 calories. This is because fat is a denser source of calories than either protein or carbohydrate, with more than twice as much energy per gram. This is one of the rationales for eliminating or reducing fat consumption for weight loss, as relatively small amounts contain large amounts of calories. This concept brings us to the next section, concerning diets that prefer certain macronutrients over others.
Weight gain is the result of a small or large positive calorie balance that persists over time.22 In other words, weight gain is the result of overeating relative to your energy expenditure for a period of time. It doesn’t matter what macronutrient your extra calories come from, whether it is protein, carbohydrate, or fat, if you are eating more than your body can burn in a given period of time, you will gain weight.
Excess energy is stored as fat, regardless of its source.23 However, two popular dietary frameworks, those of the low fat and the low carbohydrate diets, often focus their blame on a single macronutrient as being responsible for weight gain to a greater degree than other macronutrients. To some extent, diets that favor certain nutrients over others are on to something, but only when favoring certain macronutrients makes it easier to undereat or to avoid overeating.
Low fat diets discriminate against fat, while low carbohydrate diets discriminate against carbohydrate. Each of these diets claims that it works better than the other, and each claims to bestow on its dieters a wealth of health benefits that the opposing diet does not. And of course, followers of one always threaten followers of the other with various diseases. I believe that these two diets can coexist peacefully, and I hope that one day they shall do so, because they both offer some advantages for dieters. However, some people succeed on one of these diets while failing at the other, so some polarization occurs in the weight loss community around these two opposing dietary ideologies.
What does the research have to say about the relative merits of the low fat and low carbohydrate diets when it comes to lasting weight loss? When the total amount of calories on each diet is held constant, there is no significant variation among the weight loss effects of different diets, including low fat and low carbohydrate regimens.24 Manipulating the ratios between fat, carbohydrates, and protein has no significant effect on producing weight loss when calories are held constant.
The effectiveness of a 1500 calorie per day weight loss diet will be the same whether the diet is low in fat or low in carbohydrate, as long as you can keep your calorie intake at the prescribed 1500 calories per day. The problem, of course, is staying on the 1500 calories per day for long enough to reach your weight loss goals, and then maintaining that weight loss. Let’s move to a closer discussion of the low carbohydrate diet, a diet that often produces success in losing some weight, if not in keeping it off.
The low carbohydrate diet is in its renaissance, with new incarnations of the low carbohydrate diet cropping up over and over again under different names, and with slight variations among them. Low carbohydrate diets propose that calories are not as important as the source of these calories, and that limiting or eliminating carbohydrates from the diet is the fastest and easiest way to achieve sustainable weight loss.
Low carbohydrate proponents sometimes argue that it is impossible to lose weight or maintain a lean physique while consuming a moderate amount of carbohydrates. The usual rationale behind reducing carbohydrates is that this reduction results in a corresponding reduction in the body’s insulin levels, and lower insulin levels hasten fat loss. Insulin control rather than calorie balance, they argue, is the best way to achieve weight loss.
In studies of low carbohydrate diets, however, changes in energy balance, rather than changes in insulin levels, completely account for the weight loss that participants experience.25 Individuals on low carbohydrate diets spontaneously decrease their calorie intakes, without counting calories. This reduction in energy intake is made possible by increased levels of satiety and therefore reduced hunger on low carbohydrate diets.
Calorie reduction, not insulin reduction, is what causes individuals on low carbohydrate diets to lose weight, regardless of whether dieters count their calories. There is a very important lesson here, and that is if we can find ways to increase our levels of satiety, we will begin to eat less automatically. We will explore this concept throughout the rest of this book, as we find ways of altering our caffeine consumption to increase our feelings of fullness, so that we may undereat spontaneously and effortlessly.
When dieters succeed on low carbohydrate regimens, they do so because they have entered negative calorie balance by cutting the amount of carbohydrates in their diets and by cutting their food intakes in general, due to increased feelings of fullness. By eliminating carbohydrates and replacing them with fat and protein, many dieters are able to maintain a lowered calorie intake while feeling full and can thereby undereat relative to their energy expenditures.
However, it remains true that overeating fat or protein does contribute to weight gain. Both fat and protein are stored as fat when they are eaten in excess. Fat and protein are both broken down and either used for energy or for structural purposes, and where those purposes have been fulfilled, these macronutrients are stored in our fat cells, independent of the amount of carbohydrates that is being consumed. Many people gain weight on low carbohydrate diets when they go to extremes and overeat protein and fat, notwithstanding all of the claims that dietary fat and protein will not be stored as fat.
We’ll discuss the role of insulin in energy balance in Chapter 4, Caffeine and Insulin, but for now let’s address some of the claims made by low carbohydrate advocates that high insulin levels cause weight gain and that low insulin levels cause weight loss. What does the relevant research have to say about the role of insulin levels in weight loss? Low carbohydrate weight loss diets and diets that control insulin levels do not produce any greater weight loss or fat loss than equivalent calorie, high carbohydrate diets.26 That warrants repeating: insulin, in the absence of overeating and positive calorie balance, does not make a person fat. A comparison of the effects of the Atkins (low carbohydrate), Ornish (very low fat), Weight Watchers (balanced low calorie), and Zone (balanced low calorie) diets for weight loss revealed similar benefits for dieters who were able to stay the course for one year.27
Furthermore, as far as their impact on insulin levels, all of these diets, whether they restricted carbohydrates or not, produced a decline in insulin levels along with weight loss. This suggests that high insulin levels are a symptom of overeating, just as weight gain is, rather than the cause or determining factor. Again, we are struck by the truth that energy balance, rather than hormonal balance, is the key to changes in body composition, and hormonal balance is only important for weight loss where it can help us to undereat. (Body composition is the amount of muscle, bone, and fat tissue in the body taken in percentages and evaluated against each other. Our goals for our body compositions in this book are to decrease fat mass and to increase or at least maintain muscle and bone mass.)
The research likewise does not support the popular claim that carbohydrate ingestion makes fat loss impossible by “turning off” fat burning.28 If this claim were true, then fat loss on low calorie diets that contain moderate levels of carbohydrate would be impossible. On the contrary, all low calorie, moderate, and even high carbohydrate diets produce weight loss when they are carried out in a controlled environment (meaning the researchers are monitoring food intake). Unfortunately, some diet writers go so far as to say that if an individual goes on a low calorie diet and does not restrict carbohydrates, his body will burn muscle for energy, resulting in muscle wasting rather than fat loss. This claim, as you can guess, also is not supported by the studies we have discussed above.
As to the false claim that excess dietary fat is not stored as fat, I can only speculate as to its origins. Fat is incontrovertibly the most efficiently stored nutrient, despite the low carbohydrate mantra that dieters can eat as much fat as they want and continue to lose weight. It sounds too good to be true, and it is. That aside, the evolutionary implications of the “dietary fat isn’t stored” claim are spectacular.
If humans were unable to store energy from excess dietary fat, our species would have starved to death at any point in time that carbohydrate became scarce. In cold climates and in winter in general, we would not have been able to survive. Apparently for some low carbohydrate advocates, the human species is either extinct or otherwise has always been able to find carbohydrates in its environment.
All these false claims aside, many dieters have astounding success on low carbohydrate regimens, sometimes losing more than 50 and even more than 100 pounds. These results somewhat skew the value of low carbohydrate diets because people that have 100 or more pounds to lose generally make poor nutritional choices, and an elimination of the carbohydrates in their diets usually means no more pizza, cookies, cakes, and other fast foods. This results in a much better nutritional profile, and a significant reduction in calories.
The impressive 100 pounds lost is the result of eating less and sustaining negative calorie balance for a long enough period of time. The closer you get to your ideal weight, however, the more difficult it becomes to continue getting leaner. The calories have to decrease further, and the hormonal environment of the body has to get even better to keep appetite at bay while maintaining a healthy level of energy expenditure.
Even though the research demonstrates that insulin control by itself is not enough to prevent weight gain or create weight loss, insulin’s role in fat gain continues to be a contentious issue. Most diet writers that blame obesity on insulin don’t even try to explain how high levels of insulin cause obesity. Many authors simply say insulin is the culprit, relying on the fact that insulin plays a role in fat storage, the end. It is clear that high insulin levels usually accompany weight gain, as do a number of other health problems. However, high insulin levels are not the main cause of weight gain, but are just another symptom of “overeating disease.”
That being said, carbohydrate and insulin levels are important when they have an impact on your overall level of energy balance, and this is the situation where overeating elevates insulin levels, and the now higher insulin levels sometimes contribute to further overeating. If you tend to overeat carbohydrates when they are in your diet or if high levels of insulin contribute to your overeating, then macronutrient and hormonal balance can play an important role in your diet.
Decreasing your insulin levels has beneficial health effects and can help weight loss by increasing satiety, but not in the absence of negative energy balance. Manipulating your insulin levels or levels of carbohydrate, while keeping your overall energy intake and energy expenditure constant, will not affect weight loss in any way.29 Energy balance is first and foremost when it comes to weight loss, and all other hormonal issues should be viewed in the context of their effects on energy balance.
We will explore insulin’s role in satiety and overeating in more detail in Chapter 4, Caffeine and Insulin, where we’ll discuss how caffeine causes problems for our insulin systems that encourage overeating. Macronutrient and hormonal balance do matter when they affect energy balance, but a wholesale avoidance of carbohydrates is not necessary for most people to achieve their weight loss goals, and insulin control is by far not the only factor that a diet must consider in order to be successful.
At the opposite end of the spectrum from low carbohydrate diets are low fat diets. Low fat dieters correctly point out that fat is the most calorie-dense of the three macronutrients, containing more than twice as many calories per gram than carbohydrates and protein. Low fat dieters also correctly point out that of the three macronutrients, fat is the most efficiently stored as body fat.
Low fat advocates, of course, make some unsupported claims, such as the parallel claim that carbohydrates are never stored as fat, and so forth. Low fat diet writers sometimes claim that only dietary fat can be stored as fat and that carbohydrates will only be used as energy, the opposite of what some low carbohydrate writers claim. Then there are even more radical claims, for example that all animal food is stored as fat or that no foods of vegetable origin are stored as fat, and so on.
Claims such as these are good attention-grabbers, and in cases where they are remotely believable, they are good propaganda. Today we know that all diets work for weight loss when they produce negative energy balance for a long enough period of time. With this knowledge, we can focus on achieving negative energy balance or avoiding positive energy balance in order to achieve and maintain our body composition goals.
The proper focus of a diet is not so much the ratio of macronutrients, but the ability to sustain a specific level of energy balance, and macronutrient balance should be evaluated in its ability to maintain the desired level of energy balance. Low fat diets are as effective for fat loss as low carbohydrate diets, so long as they put the individual dieter into negative calorie balance that that individual can maintain for a long enough period of time. If the dieter in question overindulges in low fat and nonfat diet foods to such an extent as to put himself into positive calorie balance, however, he will gain weight regardless of his avoidance of fat.
Very low fat diets are usually difficult to follow because avoiding fat is both difficult and unpleasant for most people. Extremely low fat diets can also cause health problems for the dieter because fat is an essential nutrient and is necessary for health in amounts that vary among individuals. Complete and fanatical avoidance of any one nutrient is not a healthy way to approach dieting in general.
Even in this book, where you will learn that I advocate some reduction and modification of caffeine consumption, I do not advocate complete avoidance, and I do not think complete avoidance of caffeine is practical or enjoyable. Instead, the best way to reduce one’s calorie intake is to continue (or begin) to eat a varied diet that does not eliminate any particular nutrient, and to eat small portions of this healthy diet. Eating healthful foods in small amounts is the best solution for lasting weight loss, as long as this creates an energy deficit that can be maintained by the dieter for the time necessary to achieve leanness.
Both low fat diets and low carbohydrate diets work for weight loss when they sufficiently decrease an individual’s calorie intake while increasing or maintaining energy expenditure. Due to individual differences that we’ll discuss, some people have more success on a low carbohydrate diet, and others have more success on a low fat diet.
In addition to the frameworks of the low carbohydrate and low fat diets, there are a multitude of other diets currently on the market. These run the gamut and include no bread, no grain, Paleolithic, no sugar, no flour, no white food, no yeast, no meat, all meat, no fruit, all fruit, no starch, all starch, all raw, no raw, colorful food only, fasting, and so on, ad infinitum. All of these work to create weight loss when they put you in negative energy balance. So go buy all of them!
Another problem that is common to low carbohydrate, low fat diets, and some other restrictive diets is that these diets often reduce or eliminate foods that are significant sources of healthy nutrients in our diets. Healthy foods are replaced by commercially available “diet” foods that are either low in carbohydrates, low in fat, or low in whatever the dieter is supposed to avoid, depending on the diet in question.
These diet foods are usually highly processed and full of chemicals, so their propriety as a part of any diet is questionable. These restrictive diets are popular, however, and the popularity of macronutrient discrimination for weight loss is partly due to its simplistic approach, and to the ease of building a dietary plan around the elimination of a macronutrient. Completely eliminating a macronutrient such as fat, carbohydrate, or protein helps put the dieter closer to negative calorie balance, tells the dieter what he can and can’t eat, and simultaneously obviates the need to count calories.
By eliminating the need to count calories, diets that discriminate against particular foods or macronutrients have helped spread the belief that calories don’t matter, a belief that I hope we have adequately put to rest in our discussion of self-reported food intake and the “slow metabolism syndrome.”
While low calorie diets are the mainstay of obesity treatments, low calorie diets show very modest results in terms of lasting weight loss.30 In using the term “low calorie diet,” I am referring to any diet that works in creating weight loss for some period of time, because by definition, a diet that works must be lower in calories than the regular diet of said dieter. The main reason that many low calorie diets fail is the difficulty most people have in staying on these diets while being hungry.31 Low calorie diets work for those people who can keep themselves from overeating, and simply do not for those who have difficulty achieving a semblance of satiety.
A comparison of the effects of different popular weight loss diets revealed similar benefits for dieters in terms of weight loss when the dieters stuck to their diets for one year.32 However, 35-50% of the dieters in this study quit before completing the program, revealing the difficulties of adhering even to the most popular diet plans. Even when dieters are able to stick to a diet for the long run, most of the weight that dieters lose on a diet is regained within 1-3 years, regardless of the type of diet they were originally on.33 Staying on a diet is made difficult by boredom with the diet and an inability to feel full. Therefore, if we could isolate some ways in which to increase our feelings of fullness and thereby reduce our overeating, it would be much easier to lose weight.
Another problem in dieting is the tedium of counting calories. I won’t ask you to count the calories you eat, and I won’t ask you to measure your energy expenditure. You can engage in the tedious activity of tallying up your daily food intake, but there is no need to do this. As much as we all like to play with the internet calorie calculators, they can not accurately gauge metabolism with the scant parameters that they ask for, and they can give us false impressions.
Furthermore, your energy expenditure, both at rest and in physical activity, is constantly changing and adjusting itself based on your daily activity levels and nutrition. Instead of counting calories, we should focus changing our diets such that we spontaneously reduce our food intake due to greater levels of satiety. Once a satiety strategy is being employed, the best and most practical way for you to get a sense of your current energy balance is to see if you are losing or gaining weight.
If you are losing weight, you are in negative energy balance. If you are gaining weight, you are in positive energy balance. And if you are neither gaining nor losing weight, then you are in energy balance, with your energy intake and energy expenditure roughly equal. If you have trouble controlling your food intake and are having difficulty reaching a state of undereating, I will try to make this effortless for you.
You will soon learn how not only to speed up your metabolism to increase your chances of undereating and losing weight, but you will also learn how to effortlessly control your appetite simply by manipulating your caffeine intake. Does all of this sound too good to be true? Just you wait and see.
Eat less and exercise more (negative calorie balance) is the central message of most diets that work for weight loss; they just have different methodologies for achieving negative calorie balance. This is the central message of this book as well, but I want to focus on the difficulty in achieving negative calorie balance when consuming caffeine the way we typically consume it. Fortunately, with some more reading and some tweaking of your caffeine intake, negative calorie balance will take care of itself.
Successful weight loss diets, whether they are low fat diets, low carbohydrate diets, low calorie balanced diets, or any other diets, share some common elements. All diets that produce weight loss do so by putting the dieter in negative calorie balance. They do this by reducing energy intake, by increasing energy expenditure, or both. Successful weight loss diets, once they put the dieter in negative energy balance, are also relatively easy to stay on for the length of time necessary for weight loss to occur. Diets that you can live on for the long-term tend to produce feelings of satiety, so that you are not hungry while dieting.
Negative energy balance and satiety are the most important elements of a weight loss diet. Normal energy balance (neither negative nor positive) and satiety are the most important elements of a diet that maintains your current weight by keeping you from overeating and entering positive energy balance. If we whittle it down even further, we can see that satiety, by itself, is the most important factor of any diet whose goal is to lose weight or keep from gaining it, because feeling full keeps us from overeating.
While other elements such as individual motivation and a lack of boredom are also important to long-term weight loss success, avoiding hunger is more important. Satiety is an interesting phenomenon, because, as we have seen in our above discussion of high protein diets, when dieters achieve satiety, they spontaneously reduce their food intake and lose weight. Satiety is influenced by a number of factors, including an individual’s genetics, hormonal profile, and the particulars of the weight loss diet. People experience different degrees of satiety on different diets. Some dieters feel full on low carbohydrate diets, and not on low fat diets, and vice versa. Increased feelings of fullness can make a significant difference in a dieter’s ability to sustain a low level of energy balance for the long-term, and these increase feelings of fullness produce better weight loss results.34
How do we achieve high levels of satiety? Although it is to some degree an individual phenomenon, satiety is correlated with a high protein intake and with a high fiber intake.35 As we’ll discuss throughout the rest of the book, regular caffeine consumption makes satiety very difficult to achieve. As a result, reducing and modifying your caffeine consumption can produce high levels of satiety and reduce your hunger. In this way, your less-hungry body will spontaneously down-regulate its food intake, just as is the case with high protein and high fiber diets. Your cravings will diminish, you will eat less, and you will lose weight. This principle of satiety, that it causes you to automatically reduce your food intake, is one of the guiding principles of this book.
Besides the satiety principle, successful diets also take advantage of your body’s methods of energy expenditure or fat-burning. Both low carbohydrate and low fat diets do this when they shift their dieters’ food intake toward high protein and complex carbohydrate foods, respectively. In doing so, they take advantage of the thermic effect and make your body expend more energy in digestion.
In addition, high protein diets help to maintain energy expenditure by maintaining muscle mass. High protein diets can increase energy expenditure due to protein’s high thermic effect,36 and due the maintenance of muscle mass.37 This is in part due to the fact that the protein needs of the body are higher during negative energy balance as a result of increased muscle breakdown, and an increased protein intake helps to conserve the body’s muscle mass while dieters are losing weight.
Higher protein diets are able to conserve more fat-burning muscle tissue and maintain the body’s energy expenditure. That being said, some studies do find an energy expenditure advantage of high protein diets and others do not. While some studies find an energy expenditure advantage of high protein diets, when the results of studies that compare different dietary compositions on energy expenditure are averaged, there is no difference between energy expenditure on high carbohydrate and high protein diets.38 This suggests that both high carbohydrate and high protein diets can sometimes take advantage of the thermic effect or increased muscle maintenance, or both.
We should keep in mind that when studies do find an energy expenditure increase due to a high protein intake, it is found in diets where protein intake is 30-35% of energy intake and the corresponding energy expenditure increase is 70 calories per day for the average adult.39 This is not a very large increase for the average adult whose daily energy expenditure and required calorie intake are 2500 calories per day, but if we can cut 70 calories here and 70 calories there, the overall impact can be dramatic.
What we should take away from these findings, beyond that of foods’ varying thermic effects, is that lean muscle mass is significantly correlated with an individual’s metabolic rate at rest.40 For this reason, a significant portion of this book is concerned with maintaining and increasing your muscle mass, to take advantage of muscle’s fat-burning properties, however modest they may be.
Finally, most long-term successful diets prescribe exercise as part of the weight loss lifestyle. Exercise has a very strong protective effect against weight gain because exercise makes it less likely that positive energy balance will occur.41 Exercise increases dieters’ chances of long-term success, so I will talk about incorporating exercise into your routine. If you don’t have the time to exercise, however, the caffeine reduction and optimization principles should be enough to get you well on your way to lasting weight loss.
To prevent and treat obesity and create weight loss, energy intake must be reduced, and energy expenditure must be increased. Caffeine is at odds with weight loss because it decreases our feelings of satiety, contributes to overeating, and also decreases our energy expenditure while at rest. By increasing our food intake, caffeine makes lasting leanness and the reversal of weight gain difficult, if not impossible.
The caffeine modification strategies in this book are aimed at decreasing energy intake, increasing energy expenditure, and doing both of these while maintaining high levels of satiety. Satiety is the largest factor in making weight loss sustainable, and so it, and more specifically caffeine’s destruction of feelings of satiety, is the largest focus of this book. Modifying your caffeine intake can lead to both a direct spontaneous reduction in your food intake, and also an increase in your resting and active energy expenditures, resulting in significant weight loss and the prevention of weight gain.
As we will discuss more closely in the next chapter, genetic variations among individuals explain why different people respond to caffeine in different ways.42 Genetic differences also explain a host of other variations among individuals that are relevant to body composition, including but not limited to, appetite and food cravings, energy expenditure, success on different diets, and so forth.
Researchers often refer to this concept as biochemical individuality, and in the context of caffeine, it explains why one person can have a cup of coffee and feel its effects for hours, while another person won’t feel anything at all from one cup, and may need five to feel the same effects. It also partly explains why caffeine is more fattening in some than in others, and takes varying lengths of time to produce its ill effects in different people. I will return to this issue of individual differences throughout the rest of the book, as it comes up again and again in ways that are relevant for our purposes.
While individual differences help to explain why caffeine affects body composition for different individuals differently, let’s take a quick look around us. Most Americans consume caffeine on a daily basis, and most Americans have weight problems. These two statements prove nothing of course, because it is just as easy to say that everyone who is overweight breathes air. What I would like to suggest by these statements is that we are not overweight due to a lack of caffeine consumption or even an inadequate level of caffeine consumption. We are not sufferers of caffeine deficiency.
As to the ultra-lean heavy coffee drinker, he is an anomaly, and it may only be a matter of time before caffeine overrides his genetic predisposition toward skinniness. Questioning the role of caffeine in obesity and the weight gain epidemic is long overdue, and my findings may convince you that there is a strong connection between this omnipresent drug and our expanding waistlines.
Your energy balance determines whether you lose or gain weight. The two variables that make up energy balance are energy intake and energy expenditure. Weight gain and obesity are phenomena explained completely by overeating relative to one’s energy expenditure and the positive energy balance that is the result. Hormonal balance is important, but only to the extent that it affects energy balance. Macronutrient ratios are also important, but only to the extent that they affect energy balance.
In combating overeating and weight gain, the most important weapons are satiety, decreased food intake, and increased physical activity. Caffeine is not an appropriate part of a weight loss diet, because it increases overeating and decreases the body’s rate of fat burning while at rest. We’ll see how in chapters 3-6. In the next chapter, we’ll introduce the drug caffeine and the foods and beverages that carry it.