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THE CALORIE-REDUCTION ERROR

TRADITIONALLY, OBESITY HAS been seen as a result of how people process calories, that is, that a person’s weight could be predicted by a simple equation:

Calories In – Calories Out = Body Fat

This key equation perpetrates what I call the calorie deception. It is dangerous precisely because it appears so simple and intuitive. But what you need to understand is that many false assumptions are built in.

Assumption 1: Calories In and Calories Out are independent of each other

This assumption is a crucial mistake. As we’ll see later on in this chapter, experiments and experience have proven this assumption false. Caloric intake and expenditure are intimately dependent variables. Decreasing Calories In triggers a decrease in Calories Out. A 30 percent reduction in caloric intake results in a 30 percent decrease in caloric expenditure. The end result is minimal weight loss.

Assumption 2: Basal metabolic rate is stable

We obsess about caloric intake with barely a thought for caloric expenditure, except for exercise. Measuring caloric intake is simple, but measuring the body’s total energy expenditure is complicated. Therefore, the simple but completely erroneous assumption is made that energy expenditure remains constant except for exercise. Total energy expenditure is the sum of basal metabolic rate, thermogenic effect of food, nonexercise activity thermogenesis, excess post-exercise oxygen consumption and exercise. The total energy expenditure can go up or down by as much as 50 percent depending upon the caloric intake as well as other factors.

Assumption 3: We exert conscious control over Calories In

Eating is a deliberate act, so we assume that eating is a conscious decision and that hunger plays only a minor role in it. But numerous overlapping hormonal systems influence the decision of when to eat and when to stop. We consciously decide to eat in response to hunger signals that are largely hormonally mediated. We consciously stop eating when the body sends signals of satiety (fullness) that are largely hormonally mediated.

For example, the smell of frying food makes you hungry at lunchtime. However, if you have just finished a large buffet, those same smells may make you slightly queasy. The smells are the same. The decision to eat or not is principally hormonal.

Our bodies possess an intricate system guiding us to eat or not. Body-fat regulation is under automatic control, like breathing. We do not consciously remind ourselves to breathe, nor do we remind our hearts to beat. The only way to achieve such control is to have homeostatic mechanisms. Since hormones control both Calories In and Calories Out, obesity is a hormonal, not a caloric, disorder.

Assumption 4: Fat stores are essentially unregulated

Every single system in the body is regulated. Growth in height is regulated by growth hormone. Blood sugars are regulated by the hormones insulin and glucagon, among others. Sexual maturation is regulated by testosterone and estrogen. Body temperature is regulated by a thyroid-stimulating hormone and free thyroxine. The list is endless.

We are asked to believe, however, that growth of fat cells is essentially unregulated. The simple act of eating, without any interference from any hormones, will result in fat growth. Extra calories are dumped into fat cells like doorknobs into a sack.

This assumption has already been proven false. New hormonal pathways in the regulation of fat growth are being discovered all the time. Leptin is the best-known hormone regulating fat growth, but adiponectin, hormone-sensitive lipase, lipoprotein lipase and adipose triglyceride lipase may all play important roles. If hormones regulate fat growth, then obesity is a hormonal, not a caloric disorder.

Assumption 5: A calorie is a calorie

This assumption is the most dangerous of all. It’s obviously true. Just like a dog is a dog or a desk is a desk. There are many different kinds of dogs and desks, but the simple statement that a dog is a dog is true. However, the real issue is this: Are all calories equally likely to cause fat gain?

“A calorie is a calorie” implies that the only important variable in weight gain is the total caloric intake, and thus, all foods can be reduced to their caloric energy. But does a calorie of olive oil cause the same metabolic response as a calorie of sugar? The answer is, obviously, no. These two foods have many easily measurable differences. Sugar will increase the blood glucose level and provoke an insulin response from the pancreas. Olive oil will not. When olive oil is absorbed by the small intestine and transported to the liver, there is no significant increase in blood glucose or insulin. The two different foods evoke vastly different metabolic and hormonal responses.

These five assumptions—the key assumptions in the caloric reduction theory of weight loss—have all been proved false. All calories are not equally likely to cause weight gain. The entire caloric obsession was a fifty-year dead end.

So we must begin again. What causes weight gain?

HOW DO WE PROCESS FOOD?

WHAT IS A calorie? A calorie is simply a unit of energy. Different foods are burned in a laboratory, and the amount of heat released is measured to determine a caloric value for that food.

All the foods we eat contain calories. Food first enters the stomach, where it is mixed with stomach acid and slowly released into the small intestine. Nutrients are extracted throughout the journey through the small and large intestines. What remains is excreted as stool.

Proteins are broken down into their building blocks, amino acids. These are used to build and repair the body’s tissues, and the excess is stored. Fats are directly absorbed into the body. Carbohydrates are broken down into their building blocks, sugars. Proteins, fats and carbohydrates all provide caloric energy for the body, but differ greatly in their metabolic processing. This results in different hormonal stimuli.

CALORIC REDUCTION IS NOT THE PRIMARY FACTOR IN WEIGHT LOSS

WHY DO WE gain weight? The most common answer is that excess caloric intake causes obesity. But although the increase in obesity rates in the United States from 1971 to 2000 was associated with an increase in daily calorie consumption of roughly 200 to 300 calories,¹ it’s important to remember that correlation is not causation.

Furthermore, the correlation between weight gain and the increase in calorie consumption has recently broken down.² Data from the National Health and Nutrition Examination Survey (NHANES) in the United States from 1990 to 2010 finds no association between increased calorie consumption and weight gain. While obesity increased at a rate of 0.37 percent per year, caloric intake remained virtually stable. Women slightly increased their average daily intake from 1761 calories to 1781, but men slightly decreased theirs from 2616 calories to 2511.

The British obesity epidemic largely ran parallel to North America’s. But once again, the association of weight gain with increased calorie consumption does not hold true.³ In the British experience, neither increased caloric intake nor dietary fat correlated to obesity—which argues against a causal relationship. In fact, the number of calories ingested slightly decreased, even as obesity rates increased. Other factors, including the nature of those calories, had changed.

We may imagine ourselves to be a calorie-weighing scale and may think that imbalance of calories over time leads to the accumulation of fat.

Calories In – Calories Out = Body Fat

If Calories Out remains stable over time, then reducing Calories In should produce weight loss. The First Law of Thermodynamics states that energy can neither be created nor destroyed in an isolated system. This law is often invoked to support the Calories In/Calories Out model. Prominent obesity researcher Dr. Jules Hirsch, quoted in a 2012 New York Times article,⁴ explains:

There is an inflexible law of physics—energy taken in must exactly equal the number of calories leaving the system when fat storage is unchanged. Calories leave the system when food is used to fuel the body. To lower fat content—reduce obesity—one must reduce calories taken in, or increase the output by increasing activity, or both. This is true whether calories come from pumpkins or peanuts or pâté de foie gras.

But thermodynamics, a law of physics, has minimal relevance to human biology for the simple reason that the human body is not an isolated system. Energy is constantly entering and leaving. In fact, the very act we are most concerned about—eating—puts energy into the system. Food energy is also excreted from the system in the form of stool. Having studied a full year of thermodynamics in university, I can assure you that neither calories nor weight gain were mentioned even a single time.

If we eat an extra 200 calories today, nothing prevents the body from burning that excess for heat. Or perhaps that extra 200 calories is excreted as stool. Or perhaps the liver uses the extra 200. We obsess about caloric input into the system, but output is far more important.

What determines the energy output of the system? Suppose we consume 2000 calories of chemical energy (food) in one day. What is the metabolic fate of those 2000 calories? Possibilities for their use include

•heat production,

•new protein production,

•new bone production,

•new muscle production,

•cognition (brain),

•increased heart rate,

•increased stroke volume (heart),

•exercise/physical exertion,

•detoxification (liver),

•detoxification (kidney),

•digestion (pancreas and bowels),

•breathing (lungs),

•excretion (intestines and colon) and

•fat production.

We certainly don’t mind if energy is burned as heat or used to build new protein, but we do mind if it is deposited as fat. There are an almost infinite number of ways that the body can dissipate excess energy instead of storing it as body fat.

With the model of the calorie-balancing scale, we assume that fat gain or loss is essentially unregulated, and that weight gain and loss is under conscious control. But no system in the body is unregulated like that. Hormones tightly regulate every single system in the body. The thyroid, parathyroid, sympathetic, parasympathetic, respiratory, circulatory, hepatic, renal, gastrointestinal and adrenal systems are all under hormonal control. So is body fat. The body actually has multiple systems to control body weight.

The problem of fat accumulation is really a problem of distribution of energy. Too much energy is diverted to fat production as opposed to, say, increasing, body-heat production. The vast majority of this energy expenditure is controlled automatically, with exercise being the only factor that is under our conscious control. For example, we cannot decide how much energy to expend on fat accumulation versus new bone formation. Since these metabolic processes are virtually impossible to measure, they are assumed to remain relatively stable. In particular, Calories Out is assumed not to change in response to Calories In. We presume that the two are independent variables.

Let’s take an analogy. Consider the money that you earn in a year (Money In) and the money that you spend (Money Out). Suppose you normally earn and also spend $100,000 per year. If Money In is now reduced to $25,000 per year, what would happen to Money Out? Would you continue to spend $100,000 per year? Probably you’re not so stupid, as you’d quickly become bankrupt. Instead, you would reduce your Money Out to $25,000 per year to balance the budget. Money In and Money Out are dependent variables, since reduction of one will directly cause a reduction of the other.

Let’s apply this reasoning to obesity. Reducing Calories In works only if Calories Out remains stable. What we find instead is that a sudden reduction of Calories In causes a similar reduction in Calories Out, and no weight is lost as the body balances its energy budget. Some historic experiments in calorie reduction have shown exactly this.

CALORIC REDUCTION: EXTREME EXPERIMENTS, UNEXPECTED RESULTS

EXPERIMENTALLY, IT’S EASY to study caloric reduction. We take some people, give them less to eat, watch them lose weight and live happily ever after. Bam. Case closed. Call the Nobel committee: Eat Less, Move More is the cure for obesity, and caloric reduction truly is the best way to lose weight.

Luckily for us, such studies have already been done.

A detailed study of total energy expenditure under conditions of reduced caloric intake was done in 1919 at the Carnegie Institute of Washington.⁵ Volunteers consumed “semi-starvation” diets of 1400 to 2100 calories per day, an amount calculated to be approximately 30 percent lower than their usual intake. (Many current weight-loss diets target very similar levels of caloric intake.) The question was whether total energy expenditure (Calories Out) decreases in response to caloric reduction (Calories In). What happened?

The participants experienced a whopping 30 percent decrease in total energy expenditure, from an initial caloric expenditure of roughly 3000 calories to approximately 1950 calories. Even nearly 100 years ago, it was clear that Calories Out is highly dependent on Calories In. A 30 percent reduction in caloric intake resulted in a nearly identical 30 percent reduction in caloric expenditure. The energy budget is balanced. The First Law of Thermodynamics is not broken.

Several decades later, in 1944 and 1945, Dr. Ancel Keys performed the most complete experiment of starvation ever done—the Minnesota Starvation Experiment, the details of which were published in 1950 in a two-volume publication entitled The Biology of Human Starvation.⁶ In the aftermath of World War II, millions of people were on the verge of starvation. Yet the physiologic effects of starvation were virtually unknown, having never been scientifically studied. The Minnesota study was an attempt to understand both the caloric-reduction and recovery phases of starvation. Improved knowledge would help guide Europe’s recovery from the brink. Indeed, as a result of this study, a relief-worker’s field manual was written detailing psychological aspects of starvation.⁷

Thirty-six young, healthy, normal men were selected with an average height of five foot ten inches (1.78 meters) and an average weight of 153 pounds (69.3 kilograms). For the first three months, subjects received a standard diet of 3200 calories per day. Over the next six months of semi-starvation, only 1570 calories were given to them. However, caloric intake was continually adjusted to reach a target total weight loss of 24 percent (compared to baseline), averaging 2.5 pounds (1.1 kilograms) per week. Some men eventually received less than 1000 calories per day. The foods given were high in carbohydrates, similar to those available in war-torn Europe at the time—potatoes, turnips, bread and macaroni. Meat and dairy products were rarely given. In addition, they walked 22 miles per week as exercise. Following this caloric-reduction phase, their calories were gradually increased over three months of rehabilitation. Expected caloric expenditure was 3009 calories per day.⁸

Even Dr. Keys himself was shocked by the difficulty of the experiment. The men experienced profound physical and psychological changes. Among the most consistent findings was the constant feeling of cold experienced by the participants. As one explained, “I’m cold. In July I walk downtown on a sunny day with a shirt and sweater to keep me warm. At night my well fed room mate, who isn’t in the experiment, sleeps on top of his sheets but I crawl under two blankets.”⁹

Resting metabolic rate dropped by 40 percent. Interestingly, this phenomenon is very similar to that of the previous study, which showed a drop of 30 percent. Measurement of the subjects’ strength showed a 21 percent decrease. Heart rate slowed considerably, from an average of fifty-five beats per minute to only thirty-five. Heart stroke volume decreased by 20 percent. Body temperature dropped to an average of 95.8°F.¹⁰ Physical endurance dropped by half. Blood pressure dropped. Men became extremely tired and dizzy. They lost hair and their nails grew brittle.

Psychologically, there were equally devastating effects. The men experienced a complete lack of interest in everything except for food, which became an object of intense fascination to them. Some hoarded cookbooks and utensils. They were plagued with constant, unyielding hunger. Some were unable to concentrate, and several withdrew from their university studies. There were several cases of frankly neurotic behavior.

Let’s reflect on what was happening here. Prior to the study, the subjects ate and also burned approximately 3000 calories per day. Then, suddenly, their caloric intake was reduced to approximately 1500 per day. All body functions that require energy experienced an immediate, across-the-board 30 percent to 40 percent reduction, which wrought complete havoc. Consider the following:

•Calories are needed to heat the body. Fewer calories were available, so body heat was reduced. Result: constant feeling of cold.

•Calories are needed for the heart to pump blood. Fewer calories were available, so the pump slowed down. Result: heart rate and stroke volume decreases.

•Calories are needed to maintain blood pressure. Fewer calories were available, so the body turned the pressure down. Result: blood pressure decreased.

•Calories are needed for brain function, as the brain is very metabolically active. Fewer calories were available, so cognition was reduced. Result: lethargy and inability to concentrate.

•Calories are needed to move the body. Fewer calories were available, so movement was reduced. Result: weakness during physical activity.

•Calories are needed to replace hair and nails. Fewer calories were available, so hair and nails were not replaced. Result: brittle nails and hair loss.

The body reacts in this way—by reducing energy expenditure—because the body is smart and doesn’t want to die. What would happen if the body continued to expend 3000 calories daily while taking in only 1500? Soon fat stores would be burned, then protein stores would be burned, and then you would die. Nice. The smart course of action for the body is to immediately reduce caloric expenditure to 1500 calories per day to restore balance. Caloric expenditure may even be adjusted a little lower (say, to 1400 calories per day), to create a margin of safety. This is exactly what the body does.

In other words, the body shuts down. In order to preserve itself, it implements across-the-board reductions in energy output. The crucial point to remember is that doing so ensures survival of the individual in a time of extreme stress. Yeah, you might feel lousy, but you’ll live to tell the tale. Reducing output is the smart thing for the body to do. Burning energy it does not have would quickly lead to death. The energy budget must be balanced.

Calories In and Calories Out are highly dependent variables.

With reflection, it should immediately be obvious that caloric expenditure must decrease. If we reduce daily calorie intake by 500 calories, we assume that 1 pound (0.45 kilograms) of fat per week is lost. Does that mean that in 200 weeks, we would lose 200 pounds (91 kilograms) and weigh zero pounds? Of course not. The body must, at some point, reduce its caloric expenditure to meet the lower caloric intake. It just so happens that this adaptation occurs almost immediately and persists long term. The men in the Minnesota Starvation Experiment should have lost 78 pounds (35.3 kilograms), but the actual weight lost was only 37 pounds (16.8 kilograms)—less than half of what was expected. More and more severe caloric restriction was required to continue losing weight. Sound familiar?

What happened to their weight after the semi-starvation period?

During the semi-starvation phase, body fat dropped much quicker than overall body weight as fat stores are preferentially used to power the body. Once the participants started the recovery period, they regained the weight rather quickly, in about twelve weeks. But it didn’t stop there. Body weight continued to increase until it was actually higher than it was prior to the experiment.

The body quickly responds to caloric reduction by reducing metabolism (total energy expenditure), but how long does this adaptation persist? Given enough time, does the body increase its energy expenditure back to its previous higher level if caloric reduction is maintained? The short answer is no.¹¹ In a 2008 study, participants initially lost 10 percent of body weight, and their total energy expenditure decreased as expected. But how long did this situation last? It remained reduced over the course of the entire study—a full year. Even after one year at the new, lower body weight, their total energy expenditure was still reduced by an average of almost 500 calories per day. In response to caloric reduction, metabolism decreases almost immediately, and that decrease persists more or less indefinitely.

The applicability of these findings to caloric-reduction diets is obvious. Assume that prior to dieting, a woman eats and burns 2000 calories per day. Following doctor’s orders, she adopts a calorie-restricted, portion-controlled, low-fat diet, reducing her intake by 500 calories per day. Quickly, her total energy expenditure also drops by 500 calories per day, if not a little more. She feels lousy, tired, cold, hungry, irritable and depressed, but sticks with it, thinking that things must eventually improve. Initially, she loses weight, but as her body’s caloric expenditure decreases to match her lowered intake, her weight plateaus. Her dietary compliance is good, but one year later, things have not improved. Her weight slowly creeps back up, even though she eats the same number of calories. Tired of feeling so lousy, she abandons the failed diet and resumes eating 2000 calories per day. Since her metabolism has slowed to an output of only 1500 calories per day, all her weight comes rushing back—as fat. Those around her silently accuse her of lacking willpower. Sound familiar? But her weight regain is not her failure. Instead, it’s to be expected. Everything described here has been well documented over the last 100 years!

AN ERRONEOUS ASSUMPTION

LET’S CONSIDER A last analogy here. Suppose we manage a coal-fired power plant. Every day to generate energy, we receive and burn 2000 tons of coal. We also keep some coal stored in a shed, just in case we run low.

Now, all of a sudden, we receive only 1500 tons of coal a day. Should we continue to burn 2000 tons of coal daily? We would quickly burn through our stores of coal, and then our power plant would be shut down. Massive blackouts develop over the entire city. Anarchy and looting commence. Our boss tells us how utterly stupid we are and yells, “Your ass is FIRED!” Unfortunately for us, he’s entirely right.

In reality, we’d handle this situation another way. As soon as we realize that we’ve received only 1500 tons of coal, we’d immediately reduce our power generation to burn only 1500 tons. In fact, we might burn only 1400 tons, just in case there were further reductions in shipments. In the city, a few lights go dim, but there are no widespread blackouts. Anarchy and looting are avoided. Boss says, “Great job. You’re not as stupid as you look. Raises all around.” We maintain the lower output of 1500 tons as long as necessary.

The key assumption of the theory that reducing caloric intake leads to weight loss is false, since decreased caloric intake inevitably leads to decreased caloric expenditure. This sequence has been proven time and again. We just keep hoping that this strategy will somehow, this time, work. It won’t. Face it. In our heart of hearts, we already know it to be true. Caloric reduction and portion-control strategies only make you tired and hungry. Worst of all . . . you regain all the weight you have lost. I know it. You know it.

We forget this inconvenient fact because our doctors, our dieticians, our government, our scientists, our politicians and our media have all been screaming at us for decades that weight loss is all about Calories In versus Calories Out. “Caloric reduction is primary.” “Eat Less, Move More.” We have heard it so often that we do not question whether it’s the truth.

Instead, we believe that the fault lies in ourselves. We feel we have failed. Some silently criticize us for not adhering to the diet. Others silently think we have no willpower and offer us meaningless platitudes.

Sound familiar?

The failing isn’t ours. The portion-control caloric-reduction diet is virtually guaranteed to fail. Eating less does not result in lasting weight loss.

EATING IS NOT UNDER CONSCIOUS CONTROL

BY THE EARLY 1990s, the Battle of the Bulge was not going well. The obesity epidemic was gathering momentum, with type 2 diabetes following closely behind. The low-fat campaign was starting to fizzle as the promised benefits had failed to materialize. Even as we were choking down our dry skinless chicken breast and rice cakes, we were getting fatter and sicker. Looking for answers, the National Institutes of Health recruited almost 50,000 post-menopausal women for the most massive, expensive, ambitious and awesome dietary study ever done. Published in 2006, this randomized controlled trial was called the Women’s Health Initiative Dietary Modification Trial.¹² This trial is arguably the most important dietary study ever done.

Approximately one-third of these women received a series of eighteen education sessions, group activities, targeted message campaigns and personalized feedback over one year. Their dietary intervention was to reduce dietary fat, which was cut down to 20 percent of daily calories. They also increased their vegetable and fruit intake to five servings per day and grains to six servings. They were encouraged to increase exercise. The control group was instructed to eat as they normally did. Those in this group were provided with a copy of the Dietary Guidelines for Americans, but otherwise received little help. The trial aimed to confirm the cardiovascular health and weight-reduction benefits of the low-fat diet.

The average weight of participants at the beginning of the study was 169 pounds (76.8 kilograms). The starting average body mass index was 29.1, putting participants in the overweight category (body mass index of 25 to 29.9), but bordering on obese (body mass index greater than 30). They were followed for 7.5 years to see if the doctor-recommended diet reduced obesity, heart disease and cancer as much as expected.

The group that received dietary counseling succeeded. Daily calories dropped from 1788 to 1446 a day—a reduction of 342 calories per day for over seven years. Fat as a percentage of calories decreased from 38.8 percent to 29.8 percent, and carbohydrates increased from 44.5 percent to 52.7 percent. The women increased their daily physical activity by 14 percent. The control group continued to eat the same higher-calorie and higher-fat diet to which they were accustomed.

The results were telling. The “Eat Less, Move More” group started out terrifically, averaging more than 4 pounds (1.8 kilograms) of weight loss over the first year. By the second year, the weight started to be regained, and by the end of the study, there was no significant difference between the two groups.

Did these women perhaps replace some of their fat with muscle? Unfortunately, the average waist circumference increased approximately 0.39 inches (0.6 centimeters), and the average waist-to-hip ratio increased from 0.82 to 0.83 inches (2.1 centimeters), which indicates these women were actually fatter than before. Weight loss over 7.5 years of the Eat Less, Move More strategy was not even one single kilogram (2.2 pounds).

This study was only the latest in an unbroken string of failed experiments. Caloric reduction as the primary means of weight loss has disappointed repeatedly. Reviews of the literature by the U.S. Department of Agriculture¹³ highlight this failure. All these studies, of course, serve only to confirm what we already knew. Caloric reduction doesn’t cause lasting weight loss. Anybody who has ever tried it can tell you.

Many people tell me, “I don’t understand. I eat less. I exercise more. But I can’t seem to lose any weight.” I understand perfectly—because this advice has been proven to fail. Do caloric-reduction diets work? No. The Women’s Health Initiative Dietary Modification Trial was the biggest, baddest, most kick-ass study of the Eat Less, Move More strategy that has ever been or ever will be done—and it was a resounding repudiation of that strategy.

What is happening when we try to reduce calories and fail to lose weight? Part of the problem is the reduced metabolism that accompanies weight loss. But that’s only the beginning.

HUNGER GAMES

THE CALORIES IN, Calories Out plan for weight loss assumes that we have conscious control over what we eat. But this belief ignores the extremely powerful effect of the body’s hormonal state. The defining characteristic of the human body is homeostasis, or adaptation to change. Our body deals with an ever-changing environment. In response, the body makes adjustments to minimize the effects of such changes and return to its original condition. And so it is, when the body starts to lose weight.

There are two major adaptations to caloric reduction. The first change, as we have seen, is a dramatic reduction in total energy expenditure. The second key change is that the hormonal signals that stimulate hunger increase. The body is pleading with us to eat in order for it to regain the lost weight.

This effect was demonstrated in 2011, in an elegant study of hormonal adaptation to weight loss.¹⁴ Subjects were given a diet of 500 calories per day, which produced an average weight loss of 29.7 pounds (13.5 kilograms). Next, they were prescribed a low-glycemic-index, low-fat diet for weight maintenance and were encouraged to exercise thirty minutes per day. Despite their best intentions, almost half of the weight was regained.

Various hormonal levels, including ghrelin—a hormone that, essentially, makes us hungry—were analyzed. Weight loss significantly increased ghrelin levels in the study’s subjects, even after more than one year, compared to the subjects’ usual baseline.

What does that mean? It means that the subjects felt hungrier and continued to feel so, right up to end of the study.

The study also measured several satiety hormones, including peptide YY, amylin and cholecystokinin, all of which are released in response to proteins and fats in our diet and serve to make us feel full. This response, in turn, produces the desired effect of keeping us from overeating. More than a year after initial weight loss, the levels of all three satiety hormones were significantly lower than before.

What does that mean? It means that the subjects felt less full.

With increased hunger and decreased satiety, the desire to eat rises. Moreover, these hormonal changes occur almost immediately and persist almost indefinitely. People on a diet tend to feel hungrier, and that effect isn’t some kind of psychological voodoo, nor is it a loss of willpower. Increased hunger is a normal and expected hormonal response to weight loss.

Dr. Keys’s Minnesota Starvation Experiment first documented the effect of “semi-starvation neurosis.” People who lose weight dream about food. They obsess about food. All they can think about is food. Interest in all else diminishes. This behavior is not some strange affliction of the obese. In fact, it’s entirely hormonally driven and normal. The body, through hunger and satiety signaling, is compelling us to get more food.

Losing weight triggers two important responses. First, total energy expenditure is immediately and indefinitely reduced in order to conserve the available energy. Second, hormonal hunger signaling is immediately and indefinitely amplified in an effort to acquire more food. Weight loss results in increased hunger and decreased metabolism. This evolutionary survival strategy has a single purpose: to make us regain the lost weight.

Functional magnetic resonance imaging studies show that areas of the brain controlling emotion and cognition light up in response to food stimuli. Areas of the prefrontal cortex involved with restraint show decreased activity. In other words, it is harder for people who have lost weight to resist food.¹⁵

This has nothing whatsoever to do with a lack of willpower or any kind of moral failure. It’s a normal hormonal fact of life. We feel hungry, cold, tired and depressed. These are all real, measurable physical effects of calorie restriction. Reduced metabolism and the increased hunger are not the cause of obesity—they are the result. Losing weight causes the reduced metabolism and increased hunger, not the other way around. We do not simply make a personal choice to eat more. One of the great pillars of the caloric-reduction theory of obesity—that we eat too much because we choose to—is simply not true. We do not eat too much because we choose to, or because food is too delicious, or because of salt, sugar and fat. We eat too much because our own brain compels us to.

THE VICIOUS CYCLE OF UNDER-EATING

AND SO WE have the vicious cycle of under-eating. We start by eating less and lose some weight. As a result, our metabolism slows and hunger increases. We start to regain weight. We double our efforts by eating even less. A bit more weight comes off, but again, total energy expenditure decreases and hunger increases. We start regaining weight. So we redouble our efforts by eating even less. This cycle continues until it is intolerable. We are cold, tired, hungry and obsessing about calories. Worst of all, the weight always comes back on.

At some point, we go back to our old way of eating. Since metabolism has slowed so much, even resuming the old way of eating causes quick weight gain, up to and even a little past the original point. We are doing exactly what our hormones are influencing us to do. But friends, family and medical professionals silently blame the victim, thinking that it is “our fault.” And we ourselves feel that we are a failure.

Sound familiar?

All dieters share this same sad story of weight loss and regain. It’s a virtual guarantee. The cycle has been scientifically established, and its truth has been forged in the tears of millions of dieters. Yet nutritional authorities continue to preach that caloric reduction will lead to nirvana of permanent weight loss. In what universe do they live?

THE CRUEL HOAX

CALORIC REDUCTION IS a harsh and bitter disappointment. Yet all the “experts” still agree that caloric reduction is the key to lasting weight loss. When you don’t lose weight, they say, “It’s your fault. You were gluttons. You were sloths. You didn’t try hard enough. You didn’t want it badly enough.” There’s a dirty little secret that nobody is willing to admit: The low-fat, low-calorie diet has already been proven to fail. This is the cruel hoax. Eating less does not result in lasting weight loss. It. Just. Does. Not. Work.

It is cruel because so many of us have believed it. It is cruel because all of our “trusted health sources” tell us it is true. It is cruel because when it fails, we blame ourselves. Let me state it as plainly as I can: “Eat Less” does not work. That’s a fact. Accept it.

Pharmaceutical methods of caloric reduction only emphasize the spectacular failure of this paradigm. Orlistat (marketed in the U.S. as Alli) was designed to block the absorption of dietary fat. Orlistat is the drug equivalent of the low-fat, low-calorie diet.

Among its numerous side effects, the most bothersome was euphemistically called fecal leakage and oily spotting. The unabsorbed dietary fat came out the other end, where it often stained underwear. Weight-loss forums chimed in with useful advice about the “orange poop oil.” Never wear white pants. Never assume it’s just a fart. In 2007, Alli won the “Bitter Pill Award” for worst drug from the U.S. consumer group Prescription Access Litigation. There were more serious concerns such as liver toxicity, vitamin deficiency and gallstones. However, orlistat’s insurmountable problem was that it did not really work.¹⁶

In a randomized, double-blind controlled study,¹⁷ four years of taking the medication three times daily resulted in an extra 6 pounds (2.8 kilograms) of weight loss. But 91 percent of the patients complained of side effects. It hardly seemed worth the trouble. Sales of the drug peaked in 2001 at $600 million. Despite being sold over the counter, by 2013, sales had plummeted to $100 million.

The fake fat olestra was a similarly ill-conceived notion, born out of caloric-reduction theory. Released to great fanfare several years ago, olestra was not absorbed by the body and thus had no caloric impact. Its sales began to sink within two years of release.¹⁸ The problem? It led to no significant weight loss. By 2010, it landed on Time magazine’s list of the fifty worst inventions, just behind asbestos.¹⁹