Swapping animal products for plant-based foods leads to weight loss: new study

The new analysis looked at the role processed foods played in weight loss

Replacing animal products with plant-based foods, regardless of their level of processing, can lead to significant weight loss, according to new research by the Physicians Committee for Responsible Medicine published in the journal Nutrition & Metabolism.

“Our research shows that choosing a bagel instead of bacon for breakfast or a veggie burger instead of a hamburger for dinner is the best option if you are looking to lose weight,” says Hana Kahleova, MD, PhD, director of clinical research for the Physicians Committee for Responsible Medicine. “Filling your plate with plant-based foods—even if they are considered ultra-processed like soy milk and vegan meat and yoghurt alternatives—instead of animal products can have a positive impact on your weight and overall health.”

The new research is a secondary analysis of a study that randomly assigned participants who were overweight to an intervention or control group for 16 weeks. Participants in the intervention group followed a low-fat, plant-based diet with no calorie limit. The control group made no diet changes. In the study, those in the vegan group boosted their metabolism, lost weight, and improved cardiometabolic risk factors, compared to those in the control group.

The new analysis looked at the role processed foods played in weight loss. The participants’ dietary records were analysed, and all foods—both animal products and plant-based foods—were categorised using the NOVA system, which assigns foods to categories based on their level of processing. NOVA category 1 is defined as unprocessed or minimally processed foods; category 2 includes processed ingredients, such as salt, sugar, oil, and butter; category 3 includes processed foods made by adding salt, sugar, and preservatives; and category 4 is composed of ultra-processed foods, greatly modified by industrial techniques and processes.

Study participants in the vegan group decreased consumption of animal products and increased plant-based foods in all four NOVA categories, which led to an average weight loss of 13 pounds (5.9 kilograms), compared to an insignificant change in the control group.