Researchers have found that a vegan diet rich in legumes helps people lose weight.
According to a recent study by the Physicians Committee for Responsible Medicine published in the Journal of the Academy of Nutrition and Dietetics, a vegan diet improves diet quality, leading to weight loss and increased insulin sensitivity. Increased consumption of legumes and reduced consumption of meat, fish and poultry were the two factors most strongly linked to weight loss.
“Our research shows that the best way to improve the quality of your health is to improve the quality of the food you eat,” says Hana Kahleova, MD, Ph.D., director of clinical research at the Physicians Committee and a study co-author. “That means avoiding animal products and following a vegan diet rich in fruits, vegetables, grains and beans.”
244 overweight people who took part in the 16-week trial were randomly divided into two groups: those who made no changes to their diet and those who followed a low-fat vegan diet consisting of vegetables, of cereals, legumes and fruits without caloric limitation. Weight, body fat, insulin sensitivity and diet quality were all monitored by the researchers. 219 people who completed the entire study and sent in their final dietary records were included in the final data analysis.
Participants on the vegan diet lost an average of 13 pounds and 9.1 pounds of body fat. Body weight and fat mass did not decrease in the group that made no dietary changes. In the vegan group, increased consumption of fruits, legumes, meat alternatives and whole grains and decreased consumption of animal products, added oils and animal fats were associated with weight loss:
- Fruit: Increased consumption of whole fruits was associated with decreased body weight.
- Legumes and Meat Alternatives: Increased pulse consumption was associated with decreased weight, fat mass, and visceral adipose tissue. Consuming more meat alternatives, including tofu, tempeh, and veggie burgers, was associated with lower body weight.
- Cereals: Increased consumption of whole grains was associated with decreased body weight and fat mass.
- Eggs and dairy products: Decreased egg consumption was correlated with decreased weight. A decrease in the consumption of high-fat dairy products was associated with a decrease in body weight and fat mass.
- Meat, fish and poultry: Reductions in the combined intake of meat, fish and poultry have been associated with weight loss and decreased fat mass.
- Added fats: Decreased intake of added animal fats was associated with decreased body weight and fat mass. Decreased intake of added oils was also correlated with decreased weight and fat mass.
The vegan group also experienced improvements in insulin sensitivity.
The vegan group’s diet quality, as measured by the Alternative Healthy Eating Index-2010 (AHEI) score, also increased by an average of 6 points, in contrast to no significant change in the group that did not modify their diet. The AHEI was developed by researchers at the Harvard School of Public Health to identify dietary habits associated with a lower risk of chronic disease. The index is made up of which foods to eat more often, such as fruits and vegetables, and which to eat less often, such as red meat and processed meat. The higher the AHEI score, the lower the risk of chronic disease.
Reference: “Changes in food and nutrient intake and diet quality on a low-fat vegan diet are associated with changes in body weight, body composition, and sensitivity to Insulin in Overweight Adults: A Randomized Clinical Trial” by Lelia Crosby, BA, RD, LD, Emilie Rembert, BS, Susan Levin, MS, RD, CSSD, Amber Green, BS, RD, LD, Zeeshan Ali, Ph.D., Meghan Jardine, MS, MBA, RDN, LD, CDE, Minh Nguyen, MS, RD, Patrick Elliott, BS, Daniel Goldstein, BA, Amber Freeman, Meka Bradshaw, Danielle N. Holtz, Richard Holubkov, Ph .D., Neal D. Barnard, MD and Hana Kahleova, MD, Ph.D., April 19, 2022, Journal of the Academy of Nutrition and Dietetics.