more than seven years of calorie counting had led to virtually no weight loss. Not even a single pound. This study was a stunning and severe rebuke to the caloric theory of obesity. Reducing calories did not lead to weight loss.
There were now two choices. First, we could respect the expensive, hard-won, scientific evidence to devise a robust, more correct theory of obesity. Or we could simply keep all our comfortable and convenient preconceived notions and biases and ignore the science. The second choice involved far less work and far less imagination. So this ground-breaking study has largely been ignored and relegated to the dustbins of nutritional history. We have been paying the pied piper every day since, as the twin epidemics of obesity and type 2 diabetes have exploded.
Real-world studies26 have only confirmed this stunning fiasco. The conventional weight-loss advice to eat fewer calories carries an estimated failure rate of 99.4 percent. For morbid obesity, the failure rate is 99.9 percent. These statistics would not surprise anybody in the diet industry or, for that matter, anybody who has ever tried to lose weight.
The Calories-In, Calories-Out theory gained widespread acceptance based on its seemingly intuitive truth. However, like a rotting melon, digging past the outer shell revealed the putrid interior. This simplistic formula is riddled with erroneous assumptions. The most important error is believing that basal metabolic rate, or Calories Out, always remains stable. But a 40-percent reduction in calorie intake is quickly met with a 40-percent decrease in basal metabolic rate. The net result is no weight loss.
The other major false assumption is that weight is consciously regulated. But no system in our body functions like that. The thyroid, parathyroid, sympathetic, parasympathetic, respiratory, circulatory, hepatic, renal, gastrointestinal, and adrenal systems are all closely controlled by hormones. Body weight and body fat are also strictly regulated by hormones. In fact, our bodies contain multiple overlapping systems of body weight control. Body fat, one of the most important determinants of survival in the wild, is simply not left to the vagaries of what we decide to put in our mouths.
HORMONES: FOOD, BODY WEIGHT, AND DIABETES
HORMONES CONTROL HUNGER, telling our body when to eat and when to stop. Ghrelin is a powerful hormone that causes hunger, and cholecystokinin and peptide YY are hormones that tell us when we are full and should stop eating. Imagine you’re at an all-you-can-eat buffet. You’ve already eaten many heaping platefuls of food and you are completely, 110-percent full.
Now, could you eat a few more pork chops? Merely the thought might make you nauseous. Yet these are the same pork chops you ate happily just a few minutes ago. The difference is that satiety hormones are exerting a powerful effect to stop you from eating. Contrary to many popular beliefs, we do not continue eating simply because food is available. Calorie consumption is under tight hormonal regulation.
Fat accumulation is truly not a problem of energy excess. It’s a problem of energy distribution. Too much energy is diverted to producing fat as opposed to, say, increasing body heat or forming new bone tissue. This energy expenditure is controlled hormonally. As long as we believed, wrongly, that excessive caloric intake led to obesity, we were doomed to failure as we uselessly tried to reduce calories.
We cannot “decide” to feel less hungry. We cannot “decide” to increase basal metabolic rate. If we eat fewer calories, our body simply compensates by decreasing its metabolic rate. If calories are not the underlying cause of weight gain, then reducing calories cannot reliably reduce weight. The most important factor in controlling fat accumulation and weight gain is to control the hormonal signals we receive from food, not the total number of calories we eat.
Obesity is a hormonal imbalance, not a caloric one. The hormonal problem in undesired weight gain is mainly excessive insulin. Thus, type 2 diabetes, too, is a disease about insulin imbalance rather than caloric imbalance.
THE ROLE OF INSULIN IN ENERGY STORAGE
HERE’S A STARTLING fact: I can make you fat. Actually, I can make anybody fat. How? It’s really quite simple. I prescribe insulin. Although insulin is a natural hormone, excessive insulin causes weight gain and obesity.
Hormones are essentially chemical messengers. They are produced by the endocrine system, a network of glands found throughout the body to maintain proper function. The pea-sized pituitary gland in the brain is often called the master gland because it produces many different hormones that control metabolic processes in other parts of the body. For example, it secretes growth hormone, which signals the rest of the body, including the bones and muscles, to grow bigger. The butterfly-shaped thyroid gland in the neck produces thyroid hormone to deliver its message to the rest of the body. When it receives this signal, the heart may beat faster, breathing may accelerate, and the basal metabolic rate may increase. Similarly, the pancreas produces insulin, a hormone that delivers several different messages mostly relating to the intake and storage of food energy.
INSULIN BASICS
WHEN WE EAT, foods are broken down in the stomach and small intestine for easier absorption. All foods are composed of three main constituents, called macronutrients. These are proteins, fats, and carbohydrates, and they are all handled differently by the digestive system. Proteins are broken down into amino acids. Fats are broken down into fatty acids. Carbohydrates, composed of chains of sugars, are broken down into smaller sugars, including glucose. Micronutrients, as the name implies, are nutrients that are necessary for good health in far smaller quantities, such as vitamins and minerals.
One of insulin’s roles is to facilitate the uptake of glucose into cells for energy, by opening a channel to allow it inside. Hormones find their target cell by binding to receptors on the cell surface, much like a key fitting into a lock. Only the correct hormone can open the receptor and deliver the message. Insulin works like the key, fitting snugly into the lock on the cell to open a gateway for glucose. Every cell in the body can use glucose for energy. Without insulin, glucose circulating in the blood cannot easily enter the cell.
In type 1 diabetes, autoimmune destruction of insulin-secreting cells leads to abnormally low levels of insulin. Without keys to open the gates, glucose cannot enter to provide energy for the cell and builds up in the bloodstream, even as the cell faces internal starvation. As a result, patients continually lose weight, no matter how much they eat, since they are unable to properly use the available food energy. Unused, this glucose is eventually excreted in the urine, even as the patient wastes away. Untreated, type 1 diabetes is usually fatal.
When people without type 1 diabetes eat, insulin rises, and glucose enters the cell to help us meet our immediate energy needs. The excess food energy is stored away for later use. Some carbohydrates, particularly sugars and refined grains, raise blood glucose effectively, which stimulates the release of insulin. Dietary protein also raises insulin levels, but not blood glucose, by simultaneously raising other hormones, such as glucagon and incretins. Dietary fats only minimally raise both blood glucose and insulin levels.
Another of insulin’s key roles is to signal to the liver that nutrients are on their way. The intestinal bloodstream, known as the portal circulation, delivers amino acids and sugars directly to the liver for processing. On the other hand, fatty acids are absorbed directly and do not pass through the liver before entering into the regular bloodstream. Since liver processing is not required, insulin signaling is not necessary and insulin levels remain relatively unchanged by pure dietary fats.
Once our immediate energy needs have been met, insulin gives
