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Why Could a Carbohydrate-restricted Diet Produce More Weight Loss?
There are various theories, but the two most likely contributors in my opinion have to do with a decrease in insulin secretion and an increase in satiety (feeling full).
CARBOHYDRATE INSULIN HYPOTHESIS
Carbohydrates, especially refined ones, cause weight gain via their stimulatory effects on insulin, the main hormone required for fat storage. Many foods spike insulin to varying degrees, but breads, pastas, sugars and refined flours are particularly potent. The USDA-promoted diet, consisting of 65% of one's daily calories deriving from carbohydrates, stimulates net insulin secretion to a greater degree than a low carbohydrate diet. As the theory goes, this excess insulin release may be chronically directing more calories into your fat cells as opposed to your body to be burnt for fuel. This, in turn, will cause the person to remain hungry since a certain amount of necessary energy did not reach the cells but rather was stored away as fat, perpetuating a vicious cycle of hunger co-existing with adipose tissue growth.
CRITICISM OF THIS THEORY
Critics point to the fact that protein spikes insulin as well as carbohydrates. Yet fat does not, so the hypothesis predicts that insulin would be elevated to a lesser degree in a diet made up mostly of non-starchy vegetables, meats and fats. Since meats consist of protein (which does spike insulin) and fat (which does not), and non-starchy vegetables have minimal insulin-effects, there is likely less total insulin release. If there is less net insulin circulating in your blood throughout a day or week or month, then one would expect less calories would be stored, and more calories would be released (and used as energy throughout your body) from your adipose tissue.
INCREASED SATIETY OF HIGH PROTEIN DIETS
Eating high-protein, high-fat foods are consistently rated as more filling, which may cause people to spontaneously eat less total calories. It has been tested and proven many times, that subjects who eat a high-protein meal report being more satisfied and often eat less in the following meal (see satiety). With this explanation, it seems that the regulation of calorie intake does not happen consciously, but rather at the cellular level, sending signals perceived consciously as fullness.
This would explain why over 70% of AWLR registrants reported not counting their calories at all. It would also be supported by the OVERWHELMING majority of members who reported that they are "rarely" or "never" hungry between meals, and that 88% reported feeling less hungry than on a low fat diet.
WHAT DO RANDOMIZED CLINICAL TRIALS SHOW?
The majority of Randomized clinical trials, the most rigorous evidence that exists today, suggest that calorie unlimited diets low in carbohydrates produce more weight loss, at least in the short term. There are at least 14 randomized clinical trials demonstrating this. This is not always the case, and sometimes people assigned to consume a low fat, calorie restricted diet high in carbohydrates lose similar amounts of weight as their low carb counterparts(Click here for a list of these studies).
But the real question is, if a low calorie high carbohydrate diet is the standard of care today, where is the evidence supporting it to counter these 14 randomized clinical trials? I have never seen one, and am confident they do not exist. If you can find one, please send it to me and it will be posted. This challenge has been pending for almost a year with no takers.
But the real question is, if a low calorie high carbohydrate diet is the standard of care today, where is the evidence supporting it to counter these 14 randomized clinical trials? I have never seen one, and am confident they do not exist. If you can find one, please send it to me and it will be posted. This challenge has been pending for almost a year with no takers.
