Opinion | Carbohydrates, not energy, could also be responsible for weight problems

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David S. Ludwig is director of the New Balance Foundation Obesity Prevention Center at Boston Children’s Hospital, professor of pediatrics at Harvard Medical School, and professor of nutrition at the Harvard TH Chan School of Public Health.

The conventional way of understanding obesity is simple: if you consume more calories than you need to fuel yourself, the excess is stored as body fat and you gain weight. Because according to this view all calories are the same body, the only way to lose weight is to eat less of it or burn more of it through exercise.

For a century, this concept of “energy balance” has dominated the prevention and treatment of obesity since its initial focus calorie counting At the beginning of the 20th century low fat diet (for the most energy-rich nutrients) 20th century. at the end, and has recently been emphasized modern processed food high in fat and sugar.

However, if this theory is correct, it is difficult to accept the facts. After more than three decades of increased calorie intake in the United States since 2000, decreased or decreased. a new analysis concludes. But obesity rates have risen by more than a third since then, to a staggering 42 percent of the population today. This paradox cannot simply be explained by our sedentary lifestyles—in fact, Americans have become somewhat more physically active over the past 20 years.

What if the focus on calories and energy balance is simply wrong, and cause and effect are reversed? Writing to European Journal of Clinical Nutrition This week, my co-authors—scientists, doctors, public health experts—and I argue that overeating is not the primary cause of obesity. Instead, the process of weight gain causes us to overeat.

It’s a different model of obesity, carbohydrate-insulin model. This theory blames the rise in obesity on the processed, fast-digesting carbohydrates that flooded our diets during the low-fat diet craze—white bread, white rice, ready-to-eat breakfast cereals, potato products, and sugary foods. Eating these carbs is said to send insulin levels too high and cause other hormonal changes that program our bodies to store extra fat.

From this point of view, obesity is not a problem of overeating, but a problem of calorie distribution – too many calories from each meal go into adipose tissue and too few remain in the blood to meet the body’s energy needs. Consequently, our brain makes us feel hungry more quickly after a meal to compensate for those calories. If we try to ignore hunger and restrict calories, the body conserves energy by slowing down the metabolism. In this sense, obesity is a state of starvation in the midst of plenty.

According to this theory, simply cutting calories doesn’t work long-term because it doesn’t help store excess fat caused by hormones and other biological influences. Instead, the focus should be on reducing postprandial blood glucose and insulin spikes by eating a higher-fat diet that is low in processed carbohydrates. In this way, adipose tissue can be persuaded to release stored calories, which will reduce hunger. Weight loss occurs without calorie restriction, increasing the likelihood of long-term success.

So is the carbohydrate-insulin model more accurate than energy balance thinking? Unfortunately, we don’t know for sure yet. The definitive studies needed to resolve this controversy have never been conducted, in part because alternative obesity paradigms have not been taken seriously.

Two scientifically papers, in addition to our new one this week, we sought to build a model of carbohydrates and insulin from the available scientific evidence. But there were more than a a dozen papers from critics claiming refute the model based on weak evidence, such as small, short-term studies of two weeks or less.

Meanwhile, despite the investment in a lot major low fat trials of the diet (almost all of which showed no benefit on primary outcomes), the government’s National Institutes of Health has yet to fund one long-term low-carb trial of similar scope. It was not a fair contest of ideas.

One reason for this resistance may be cultural. For centuries obesity has been considered a character flaw. Despite decades of research genetic and biological influences When it comes to body weight, obese people continue to be stigmatized, more so than those with almost any other chronic disease, as if their weight is their fault.

Energy balance thinking indirectly contributes to these stereotypes by blaming poor self-control for overeating. Although newer versions of energy balance Emphasize the primary reward centers in the brain that drive food intake, either way obese people can’t resist tempting foods for conscious or subconscious reasons. But if the alternative paradigm is correct, then deeply held beliefs about obesity are simply wrong.

Scientists are supposed to be skeptical. But when variations on the same approach keep failing—and obesity rates keep rising—it’s critical that new ideas are encouraged, not stifled. In addition, only one weight-related complication, type 2 diabetes, costs nearly as much 1 billion dollars a daywe need to consider different ways to tackle the intractable problem of obesity and open our minds to the radical-sounding idea that overeating is a symptom, not a cause.

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