Vegan diets may boost weight loss and help manage blood sugar after 12 weeks, research suggests

• There's even more evidence a vegan diet may help with weight loss, blood sugar, and cholesterol.
• Eating vegan helped participants in diet trials lose weight in 12 weeks, research shows.

Trying a vegan diet for a few months may lead to significant weight loss and improvements in blood sugar control, suggests new research presented at the European Congress on Obesity, May 4-7.

Researchers from the Steno Diabetes Center in Copenhagen, Denmark looked at data from 11 randomized trials on vegan diets, involving a total of 796 participants with obesity or type two diabetes. The trials compared vegan diets with either a control group (who followed their typical eating habits) or another diet, such as the Mediterranean diet, for at least 12 weeks, and 19 weeks on average.

Participants on a vegan diet lost about nine pounds on average across all the trials. The vegan groups lost 16 pounds more, on average, compared to control groups, and nearly six pounds more on average than participants on other diets, according to the data. Vegan diets also led to modest improvements in blood sugar and cholesterol levels.

The results suggest that vegan diets could be a useful tool for managing weight and diabetes, according to Anne-Ditte Termannsen, lead author of the research and PhD student at the Steno Diabetes Center.

"This rigorous assessment of the best available evidence to date indicates with reasonable certainty that adhering to a vegan diet for at least 12 weeks may result in clinically meaningful weight loss and improve blood sugar levels," Termannsen said in a press release.

Vegan diets may aid weight loss by helping you feel full while eating less

There's no one right way to eat vegan, and plant-based diets can vary widely in the proportion of different nutrients like protein, fat, and carbohydrates. The trials included in this latest research didn't define specific parameters for the vegan diets, or match diets based on nutrients and calories.

As a result, it's likely that people on vegan diets lost more weight because they were eating fewer calories overall, according to Termannsen.

"Vegan diets likely lead to weight loss because they are associated with a reduced calorie intake due to a lower content of fat and higher content of dietary fiber," Termannsen said.

Plant-based foods tend to be lower in fat, which is the most energy-dense macronutrient at nine calories per gram (compared to four calories per gram for both protein and carbs). As a result, vegan meals can include a lot of food by volume — such as a heaping plate of veggies — while still being low-calorie, making plant-based food convenient for feeling full in a calorie deficit for weight loss.

Vegan staples like whole grains, beans, nuts, and seeds are also rich in fiber, a type of carbohydrate that doesn't break down easily in the digestive system. Getting enough fiber can also help manage appetite by slowing down your digestion, so you feel satisfied for longer after eating.

High fiber in vegan diets has benefits for blood sugar and digestive health, too

By slowing digestion, fiber not only staves off hunger, but also regulates how quickly your body absorbs other nutrients, including glucose from breaking down other carbohydrates. Managing glucose absorption is key for stable blood sugar levels, so fiber plays a major role in preventing blood sugar spikes and crashes.

There's also evidence that eating plenty of fiber supports a healthy gut microbiome, the beneficial bacteria that live in your digestive system.

Previous research has linked vegan diets to a healthier gut microbiome with benefits for preventing diabetes and heart disease, as well as boosting weight loss and fat burning.