A diet rich in healthy carbohydrates -- found in fruits, vegetables, and whole grains -- can reduce body weight and improve insulin function in overweight individuals, a study claims.
In the 16-week clinical trial, researchers with the US-based nonprofit Physicians Committee for Responsible Medicine placed participants in either a plant-based, high-carbohydrate, low-fat diet group or asked them to maintain their current diet.
"Fad diets often lead people to fear carbohydrates. But the research continues to show that healthy carbohydrates -- from fruits, vegetables, beans, and whole grains -- are the healthiest fuel for our bodies," said Hana Kahleova, lead author of the study published in the journal Nutrients.
The plant-based diet group avoided all animal products and added oils and limited fat intake to 20-30 grams per day. There were no limits on calories or carbohydrate intake.
The control group maintained their current diets, which included meat and dairy products. Neither group altered their exercise routines.
Total carbohydrate intake did not change in the control group, but increased significantly in the plant-based diet group, both as absolute intake and as a percentage of total calories.
Participants focused on whole, complex carbohydrates from fruits, vegetables, whole grains, and legumes.
At the end of the trial, body mass index, body weight, fat mass, visceral fat volume, and insulin resistance decreased significantly in the plant-based diet group. There were no significant changes in the control group.
The study's results support previous research finding that a plant-based, high-carbohydrate diet can help with weight regulation and body composition and reduce the risk for type 2 diabetes.
Complex carbohydrates are naturally rich in fiber -- a nutrient found in plant foods that add bulk to the diet without adding extra calories.
Previous studies have shown that high-fiber diets are effective for weight loss and can help reduce the risk for type 2 diabetes, heart disease, and certain types of cancer.