Eat Less. Cut your calories. Watch your portion size. Those form the foundation of conventional weight loss advice over the last 50 years. And it's been an utter disaster, perhaps only topped by the nuclear meltdown of Chernobyl. This advice is all based on a false understanding of what causes weight gain.
Why don't we ever consider the critical question of "What causes obesity?" We believe that we already know the full answer. It seems so obvious, doesn't it? We think that excessive intake of calories causes obesity. We think that this is a caloric imbalance. Too many 'calories in' compared to too few 'calories out' leads to weight gain. This Calorie Balance model of obesity has been drilled into us since childhood.
The underlying, unspoken premise is that these are independent variables fully under conscious control. This completely ignores the multiple overlapping hormonal systems that signal hunger and satiety. This further assumes that basal metabolism remains stable and unchanging.
But these assumptions are known to be incorrect. Basal metabolic rate can adjust up or down by forty percent. Restriction of calories invariably leads to a reduction in metabolism, ultimately defeating weight loss efforts.
For the last 50 years, we have unquestioningly followed this 'Caloric Reduction as Primary' program. Dietary fat, being high in calories were restricted. We made food guides, food pyramids, and food plates to indoctrinate children into this brand new low-calorie religion. 'Cut your calories' was hymn of the day. "Eat Less, Move More!" we chanted.
Nutrition labels were mandated to include calorie counts. Programs and apps were created to more precisely count calories. We invented small appliances like Fitbits to measure exactly how many calories we were burning. Using all of the ingenuity that makes us human, focused like a laser beam, and dogged as a turtle crossing a road, we cut calories. What was the result? Did the problem of obesity simply fade away like the morning mist on a hot summer day?
The results could hardly have been worse if we had tried. The storm of obesity and type 2 diabetes started in the late 1970's and today, some forty years later, it has become a global Category 5 hurricane, threatening to engulf the entire world.
What went wrong?
Only two possibilities can explain how obesity could spread so rapidly in the face of this shiny new advice to reduce fat and calories. Perhaps the 'Caloric Reduction as Primary' advice is simply wrong. The second possibility is that this advice was good, but people simply were not following it. The spirit was willing but the flesh was weak.
This is the game called, "Blame the Victim". This shifts the blame from the advice giver (the advice is bad) to the advice taker (the advice is good, but you are not following it). Was the entire obesity epidemic simply a sudden, simultaneous, coordinated, worldwide lack of willpower? The world can barely agree upon which side of the road we should drive, but yet, without discussion we all decided to eat more and move less?
By declaring that their scientifically unproven caloric reduction advice was flawless, doctors and nutritionists could conveniently shift the blame from themselves to you. It wasn't their fault. It was yours. No wonder they loved this game so much! To admit that all their precious theories of obesity were simply incorrect was too psychologically difficult. Yet evidence continued to accumulate that this new caloric restriction strategy was about as useful as comb to a bald man.
But when the final results were tallied in 2006, there was only crushing disappointment. Despite good compliance, over 7 years of calorie counting 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.
So, there were now two choices. First, we could respect the expensive, hard-won scientific evidence to devise a most robust, more correct theory of obesity. Or, we could simply keep all our convenient, preconceived notions and ignore the science. The second choice involved far less work and far less imagination. So, this groundbreaking study has largely been ignored and relegated to the dustbins of nutritional history. We have been paying the pied piper every since, as the twin epidemics of obesity and type 2 diabetes explode.
Real world studies only served to confirm this stunning fiasco. Conventional dietary treatment of obesity carries an estimated 99.4% failure rate. For morbid obesity, the failure rate is 99.9%. These statistics would not surprise anybody in the diet industry, or even, for that matter, anybody who has ever tried to lose weight.
The Calories In, Calories Out theory had gained widespread acceptance based on its seemingly intuitive truth. However, like a rotting melon, digging past the outer shell reveals the putrid interior. This simplistic formula is riddled with erroneous assumptions.
Why doesn't calorie counting work?
The most important source of error is that reducing 'Calories In' leads to a reduction in metabolic rate, or 'Calories Out'. A 30% reduction in calorie intake is quickly met with a decrease in basal metabolic rate of 30%. The net result is that no weight is lost.
The other major false assumption is that weight is consciously regulated. But no system in our body is wholly unregulated 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. 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 not simply left to the vagaries of what we decide to put in our mouths.
Hormones control hunger, telling our body when to eat and when to stop. Ghrelin is a powerful hormone that causes hunger, and cholecystikinin and peptide YY are hormonal satiety signals, which tell us that we are full and should stop eating.
Think about the last time you were at the all-you-can-eat buffet. Imagine that you've already eaten many heaping platefuls of food, and you are completely, 110% full. Now, could you eat a few more pork chops? Merely the thought might make you nauseous. Satiety hormones are exerting a powerful effect to stop you from eating. Contrary to many popular beliefs, we do not simply continue eating simply because food is available. Calorie consumption is under tight hormonal control.
Hormones also regulate our basal metabolic rate, the baseline level of energy needed to keep our bodies running normally. This is the energy used to generate body heat, to power our heart muscles, our lungs, our liver, our kidneys, etc. Low caloric intake reduces basal metabolic rates as much as 40% in an effort to conserve energy. Deliberate over-feeding increases basal metabolic rates as the body tries to 'burn' off the excess energy.
Fat accumulation is really not a problem of energy excess. It's a problem of energy distribution. Too much energy is diverted to fat production as opposed to, say, increasing, body-heat production. This energy expenditure is controlled hormonally. For example, we cannot decide how much energy to expend on fat accumulation versus new bone formation. Therefore, what is important is how to control the hormonal signals we receive from food, not the total number of calories we eat..
As long as we believed, wrongly, that excessive caloric intake led to obesity, we were doomed to failure. Under this paradigm, 500 calories of brownies is just as fattening as 500 calories of kale salad, a notion that is clearly ridiculous. Blaming the victim turned obesity from a hormonal disorder into a moral failure and excused medical professionals from their botched attempts to treat the obesity epidemic.
We could not 'decide' to be less hungry. We could not 'decide' to increase basal metabolic rate. If ate less calories, our body simply compensated by decreasing metabolic rate. Different foods evoke different hormonal responses. Some foods were more fattening than others. Calories were not the underlying cause of weight gain. Therefore, reducing calories could not reliably reduce weight.
Obesity is a hormonal, not a caloric imbalance. The hormonal problem was mainly insulin.
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Jason Fung