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Low-carb diets: An easy way to lose weight or recipe for heart attack?

More people are cutting carbs and filling up on fat and protein to lose weight or get healthier – despite warnings about this boosting cholesterol. New Scientist investigates the true risks of low-carb life

By Clare Wilson

6 January 2021

New Scientist. Science news and long reads from expert journalists, covering developments in science, technology, health and the environment on the website and the magazine.

Jason Ford

COUNTLESS fad diets come and go, but these days there is one we never stop hearing about. Whether you call it low-carbing, Atkins, keto or paleo, the principle is the same: cutting down on starchy food and filling up on fat and protein.

Low-carbohydrate diets are increasingly being endorsed by obesity and diabetes specialists, and a growing number of trials show that the approach helps people lose weight at least as much as traditional low-fat, low-calorie regimes. More and more people are eating this way, not to lose weight, but because they see it as healthier.

Yet many doctors warn that low-carbing is dangerous. They point to large-scale population studies linking low-carb diets to increased risk of heart attack, stroke and premature death.

The puzzling thing is, those warnings don’t seem to square with findings from clinical trials, generally a better kind of medical evidence than population studies. Several have now shown that low-carb diets generally don’t raise the levels of “bad cholesterol”, long seen as a major risk factor for heart attack and stroke. Even in people who do see a rise, other markers of heart health usually improve.

It is so confusing that some wonder if we have got the causes of heart disease all wrong. “This has led me to question whether I believe in the cholesterol hypothesis at all,” says Eric Westman, an obesity specialist at Duke University in North Carolina.

As rising rates of obesity and diabetes threaten public health, the questions around the safety of low-carb diets are becoming increasingly urgent. So, is ditching carbs a safe way to lose weight and stay…

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