Most weight loss or maintenance diets warn against excess carbohydrates. But what about carbohydrates found in plants, those complete and complex carbohydrates found in fruits, vegetables, whole grains and legumes? According to this study by the Physicians Committee for Responsible Medicine, a Washington-based nonprofit research and advocacy organization, published in Nutrients, diets high in these types of carbohydrates do promote fat and body weight loss and improve insulin function in overweight people.
This 16-week randomized clinical trial asked its participants to follow, among other things, a plant-based, high-carb, low-fat diet vs. maintenance of the usual diet. The intervention group was to avoid all animal foods and added oils and limit their fat intake to 20-30 grams per day. On the other hand, it had no limit for the intake of calories or vegetable carbohydrates. Both groups continued with their exercise routines. Total carbohydrate intake did not change in the control group, but increased significantly in the plant-based diet group, both as an absolute intake and as a percentage of calorie intake. Participants focused on whole and complex carbohydrates from fruits, vegetables, whole grains and legumes. Experience shows that in the intervention group:
- body mass index (BMI), body weight, fat mass, visceral fat volume and insulin resistance decreased significantly vs no significant change in control group.
This research adds to the evidence that “healthy carbohydrates , those found in fruits, vegetables, beans and whole grains are the healthiest fuel for our bodies,” says lead author Dr. Hana Kahleova, Director of Clinical Research for the Physicians Committee for Responsible Medicine. This is indeed not the first demonstration that a plant-based carbohydrate diet can help control weight and body composition and reduce the risk of type 2 diabetes: a recent study published in the Lancet had also shown that people who consume diets low in carbohydrates of animal origin have a longer life expectancy.
Complex carbs are naturally high in fiber which adds "mass" to the diet without adding extra calories. High fiber diets are already well documented as effective for weight loss and preventing the risk of type 2 diabetes, heart disease and certain types of cancer.
Important implications, therefore, and which corroborate the interest of consuming at least 5 servings of fruits and vegetables per day.
