Low-Fat Vegan Diet Cut the Calorie Density of Food by Nearly a Third, Helping Weight Loss

A low-fat vegan diet cuts the number of calories packed into each bite of food by about 30%, letting people eat just as much and still lose weight, according to a new analysis of a randomised trial published in JAMA Network Open on August 6.

Researchers at the Physicians Committee for Responsible Medicine analyzed a 16-week trial in which adults with overweight either switched to a low-fat vegan diet of fruit, vegetables, grains and legumes, eating as much as they liked, or made no changes. Neither group had calorie limits.

Energy density, the calories per gram of food, dropped about 30% in the vegan group and did not change in the control group. The weight of food people ate stayed the same, yet calorie intake fell by about 357 kcal a day more in the vegan group. Bigger drops in energy density went with more weight loss, even after accounting for calories, the Physicians Committee reports.

"This helps answer a question people often have about plant-based eating: How can you lose weight without counting calories or going hungry?" said lead author Dr Hana Kahleova. "The answer is energy density. Plant foods are rich in water and fiber, so you can fill your plate, feel full, and still take in fewer calories."

Vegetables and legumes did most of the work, so piling the plate high with them is a fine strategy.

It follows last month's UK Biobank study linking whole plant foods to an 11% lower risk of weight gain and the same team's finding that a vegan diet lowers dietary acid load.

Eat more, weigh less. What's not to love?