Carbs and obesity: Is there more than meets the eye?

Carbs and obesity: Is there more than meets the eye?


The well-known “carbohydrate-insulin model” dictates that the carbohydrates in food can cause a spike in insulin, which encourages the body to store fat while increasing appetite. The result? Overeating.

Or so we thought.

Now, new research published in the journal Science suggests this process is an oversimplification of carbohydrates’ actual role in weight management. Although low-carb diets prove effective for some individuals, scientists are exploring whether insulin’s effect on fat-storing cells after a carb-heavy meal is the only culprit in weight gain.

Instead, the study’s researchers suggest that insulin’s role in obesity may be better understood by looking at its actions on various organs — actions that are prompted by factors mostly unrelated to carbohydrate consumption.

The study’s authors point to a 2020 study that compared the effects of 29 distinct diets on body fat in mice.

Sixteen of the diets were characterized by a consistent intake of protein while titrating the different contributions of carbohydrates and fats to each mouse’s caloric intake. According to the carb-insulin model, mice whose diets contained more carbs should have seen higher insulin levels after each meal, resulting in laying down fat and increasing their appetite.

Accordingly, the mice displayed higher insulin levels after eating.

But after the equivalent of nine years in humans (about three months for mice), mice who consumed diets high in carbs were eating fewer calories, gaining less fat and body weight as a whole.

Of course, a mouse study is not equivalent to one in humans. For now, exonerating carbs from their reputation as weight-gain culprits will require more robust research in the future.

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