Low-fat vegan diet is better than keto for weight loss: study

• A new study has found that a low-fat, plant-based diet may help people lose weight and burn body fat.
• But a ketogenic diet based on animal meat and high in fat has been shown to be better at managing insulin and blood sugar.
• It is still not clear why certain diets cause weight gain, but processed foods are a major risk factor for obesity.
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When it comes to healthy eating, which diet is better can be hotly contested.

Proponents of the ketogenic diet suggest that a diet low in carbohydrates and high in fat is superior and that butter, bacon, and eggs can be healthy foods. But other experts say we should aim for a low-fat, plant-based diet consisting of whole grains and vegetables instead.

The two diets were pitted face to face in a new study published Jan.21 in Nature Medicine.

According to research conducted by the US National Institutes of Health (NIH), a low-fat diet can lead to greater fat loss, while a keto diet can better manage blood sugar.

Read more: Nutrition journalist and keto advocate defends fad diets, saying traditional tips don’t work for everyone

The key to this study is to help us understand which nutrients can lead to hunger and weight gain, according to Dr. Kevin Hall, lead author of the study and NIH lead researcher.

“It is not designed to test whether one diet is better than another, it is designed to test the biology of what regulates appetite in people when they are not actively trying to change body weight.” , Hall told Insider.

Plant-Based Diet Can Boost Weight Loss, Even With High Carbohydrates

Hall studied 20 non-diabetic adults who, during a two-week stay at the NIH Clinical Center, were randomly given a low-fat, plant-based diet, or a low-carbohydrate diet based on animals.

Then they switched to the other diet and stayed for another two weeks.

Hall’s study found that participants consumed about 500-700 fewer calories per day on a plant-based diet, even though they ate more food – mostly foods high in carbohydrates and fiber.

They also lost a significant amount of weight and body fat compared to the keto diet, which suggests that carbs alone are not responsible for weight gain.

These results are, however, consistent with many previous studies that have linked vegan and vegetarian diets to weight loss and other health benefits such as better digestion and a healthier gut microbiome.

However, this contradicts a theory, popular among keto carbohydrate advocates, that eating too much carbohydrate causes insulin spikes that trigger fat storage.

“We were testing a few different ideas about the causes of overeating and weight gain, the theories of obesity. The popular recent idea is that it’s all about insulin, that hasn’t proven to be true,” Hall said.

Jasmin Merdan / Getty Images

High-fat keto diet may be better at stabilizing blood sugar

Hall’s study found that the keto diet also helped participants lose weight, but mostly water weight, without a significant reduction in body fat.

The keto diet did have a benefit, however, in helping people manage their blood sugar (glucose) levels. Study participants produced about 60% less insulin on a low-carb diet than on a low-fat diet. This is because eating carbohydrates increases your blood sugar, so eating more carbohydrates requires more insulin to balance things out.

These findings are consistent with the existing evidence that supports the use of low-carb diets to manage diabetes.

“One of the cool things about the potential of ketogenic diets is that you don’t need to make a lot of insulin,” Hall said.

People could eat more calories and maintain weight on keto

While people on a low fat, plant-based diet could eat more food while consuming fewer calories, people on a keto diet had their own advantage.

Participants of the keto diet could consume more high-calorie foods like butter, cream, and cheese without gaining weight.

Previously, nutrition experts hypothesized that high-calorie foods make it easier to overeat and therefore gain weight.

But that didn’t happen with a ketogenic diet, according to the study.

“The data suggested that people ate more or less the same number of calories they started out,” Hall said.

These results suggest that high-calorie foods don’t automatically make us overeat. If these high-fat foods are satisfactory, dieters will end up eating less and therefore not consuming the extra calories that could lead to weight gain.

Keto and plants are healthier than a diet high in processed foods

The benefits of keto or plant-based diets, however, might be less related to carbohydrates or fats and more than they include whole foods, instead of ultra-processed foods like chicken nuggets, soda and more. white bread.

“A diet high in ultra-processed foods is the only one we’ve found results in overeating and weight gain,” Hall said.

In addition to weight gain, processed foods are also linked to a higher risk of chronic diseases such as cancer and heart disease, more severe symptoms of aging, and even a shorter lifespan.

But, Hall said, he knows firsthand how difficult it can be to avoid processed foods.

As a father of two young sons, his family tries to have more vegetables on their plates, but relies on ready meals that are “inexpensive, available, easy to prepare and microbially safe” .

“I end up eating more chicken nuggets than I would like, but we eat a lot of broccoli and green beans,” he said. “Lifestyle factors influence people’s food choices more than any study I could produce.”