The insulin theory of obesity declares that the primary cause of obesity is higher carbohydrate diets because these diets increase insulin secretion more than any other diet. When insulin levels are high, fat storage will increase significantly and “starve” muscles and organs of energy. This causes increased hunger and overeating that results in obesity.
The reason why low-carb diets work, according to this theory, is that the lowered levels of insulin (caused by restricting carbs) allow for the body to begin metabolizing fat and increase energy expenditure. Some proponents of the theory think that the reason restricting carbohydrates works is because of a “metabolic advantage” (i.e., a person on a low carb diet burns more calories than a person eating a diet higher in carbohydrate).
The best part about the insulin theory of obesity is that we can conduct experiments that can, beyond a reasonable doubt, figure out if this theory holds any merit. All we need is someone to look at the results from all of the studies that compare low-carb with low-fat diets with calories and protein intake matched.
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