چرا هنوز مقدار کالری ها را میشماریم؟

Why are we still Counting Calories?

“Biggest Loser transformations have astonished and challenged a nation. In ten seasons, they’ve lost over 10 tons.” In 2016, a paper from the Journal “Obesity” was released titled “Persistent Metabolic Adaptation 6 Years After “The Biggest Loser” Competition”.

You may have heard of it as it appeared in a report on the New York Times, and it received coverage on ABC news: “News from the world of weight loss - scientists followed contestants from the TV show the Biggest Loser and they found that when the cameras went off, the weight often came back on.”

The phenomenon the study is discussing is called “metabolic adaptation,” which is where resting metabolic rate dramatically slows down in response to weight loss. Meaning, after losing a bunch of weight on a calorie restricted diet, the person’s body burns less calories, so in order to maintain their weight after the weight loss, they have to either exercise a lot more or eat several hundred calories less than someone of the same weight who didn’t have to lose any weight in the first place. “

In order to just maintain my weight, I have to eat less than 1400 calories a day. …it’s almost nothing. I’m not full, and I find myself in a constant “Well maybe I shouldn’t eat right now and…” Not only is the amount of calories burned at rest drastically reduced in these people, they are objectively hungrier.

A look at the hormones circulating in their bodies would show clearly that have less energy and have more hunger than others of the same weight. As an October 2011 study in the New England Journal of medicine says: “Caloric restriction results in acute compensatory changes, including profound reductions in energy expenditure and levels of leptin and cholecystokinin and increases in ghrelin and appetite” Less energy expenditure makes you more lethargic, less cholecystokinin means more hunger, less leptin signalling means more hunger and more ghrelin also means you’re hungrier.

“This is something that has been known in the medical and scientific community for almost 20 years, If you take two individuals, both weighing 200 pounds, the person who’s lost weight at 200 pounds has a slower metabolism, they burn fewer calories, they are hungrier than a person at the same weight.” So what do we do?

This is something I’ve discussed in other videos of mine so I won’t get into it too much, but we know that people’s hunger actually decreases when they eat nothing rather than restricting calories, thanks to Ghrelin levels decreasing the longer people fast. And, Ironically, while eating less slows down metabolism, eating nothing raises metabolism. As this study shows, resting energy expenditure actually goes up while fasting. But, prolonged fasting is obviously not always the best choice.

Luckily, intermittent fasting and low carb or ketogenic diets get you to a similar physiological state that keeps your hunger hormones in check while you lose weight. This study has found that a ketogenic diet can prevent the hormonal changes that cause people to be hungrier after weight loss.

People’s subjective experience of hunger and levels of the hunger hormone ghrelin were lower on a ketogenic diet. This kind of information reveals how important hormones are when it comes to effective and sustainable weight loss. For example, it’s also been known for a long time that the hormone insulin promotes the accumulation of fat. Given all this, why are so many health experts and people in the medical establishment so focused on calories as the primary focus for weight loss?

Why isn’t the focus to eat in such a way that modulates your hormones to where you store less fat, burn more fat and be less hungry? It might be a simple case of first come first serve. Most historians would consider the 1860’s to be the birth of modern nutrition- this was around when German researchers pioneered the use of room-sized devices called calorimeters.

This allowed them to measure precisely how much energy humans or animals expended under different conditions. Nutrition researchers were very interested in the requirements of children, soldiers and athletes in terms of vitamins, minerals, protein and of course calories. Almost a 100 years later, Rosalyn Yalow, a medical physicist, and Solomon Berson, a physician, invented the radioimmunoassay in 1960.

This new technology allowed researchers for the first time ever to measure accurately the level of hormones circulating in the bloodstream. By the time this was invented though, the calorie cutting approach to weight loss had strongly taken root.

Of course the laws of thermodynamics can’t be broken, but why not just eat in a way that makes you less hungry? And, why would anyone recommend cutting calories when it’s been clearly shown that it will make you hungry and lethargic?

Well, it might have something to do with the fact that nutritionists had almost a 100 year head start to think about diet in terms of calories, rather than hormones.