WASHINGTON, D.C.—A new study from the Physicians Committee for Responsible Medicine reveals that swapping animal products for plant-based foods, no matter how processed, can lead to significant weight loss. The findings were published in the journal Nutrition & Metabolism.
“Our research shows that making simple switches—like choosing a bagel over bacon for breakfast or a veggie burger instead of a hamburger—can be a great option for those looking to lose weight,” said Hana Kahleova, MD, PhD, director of clinical research at the Physicians Committee. “Filling your plate with plant-based foods, even processed ones like soy milk and vegan alternatives to meat and yogurt, can have a positive impact on your weight and health.”
This study is a secondary analysis of an earlier research project where overweight participants were randomly assigned to either an intervention or control group for 16 weeks. The intervention group followed a low-fat, plant-based diet with no calorie restrictions, while the control group made no dietary changes. Results showed that participants on the plant-based diet experienced weight loss, improved metabolism, and better heart health compared to those in the control group.
The new analysis focused on the role of processed foods in weight loss. Participants’ food intake was tracked and categorized using the NOVA system, which classifies foods based on their processing level. NOVA divides foods into four categories: category 1 for unprocessed or minimally processed foods, category 2 for processed ingredients like salt and oil, category 3 for processed foods with added sugar, salt, and preservatives, and category 4 for ultra-processed foods, which are heavily modified using industrial processes.
Participants in the vegan group reduced their consumption of animal products and increased plant-based foods across all four NOVA categories. As a result, they lost an average of 13 pounds (5.9 kilograms), while the control group saw no significant change.
The study identified three main factors linked to weight loss: cutting back on processed animal foods (like smoked fish), unprocessed or minimally processed animal foods (such as milk, beef, and eggs), and ultra-processed animal foods (including cheese, fried chicken, and sausage).
These changes in diet led to reduced calorie and fat intake, increased fiber consumption, and greater calorie burn from a boosted metabolism after meals.
“This study highlights that plant-based foods—whether processed or not—such as canned beans, cereal, and veggie burgers, are an important part of a healthy diet that can help address America’s chronic diet-related health problems,” Dr. Kahleova added.
