Dietary fiber is found in a variety of plant-based foods such as whole grains, fruits, vegetables, and legumes. Research supports the concept that high-fiber diets may reduce the risk of obesity and obesity-related diseases. Thus, the current Dietary Guidelines for Americans encourage ample consumption of whole grains, fruits and vegetables, and legumes. To date, however, research into the relationships between dietary fiber from specific food types and weight outcomes remains limited.
A recent study conducted in five European countries analyzed food intake data, body size measurements, and other lifestyle information for more than 89,000 adults (1). Study participants remained in the study for an average of 6.5 years, allowing for calculations of annual weight change and annual change in waist circumference. In addition to total dietary fiber intake, researchers also assessed intake of fiber from cereal grains and fiber from fruits and vegetables. The results showed that an increase of 10 grams/day of dietary fiber resulted in an average annual weight loss of 39 grams and an annual waist circumference reduction of 0.08 cm. Although these changes are small, they do support fiber’s role in preventing weight and waist circumference gain. Dietary fiber from cereal grains was similarly associated with small but significant reductions in weight and waist circumference. Fiber from fruits and vegetables was found to be associated with decreased waist circumference but not body weight.
The findings from this very large study and other studies support the current recommendations to consume plenty of dietary fiber in an effort to help prevent obesity and obesity-related risk factors.
Du H, van der A DL, Boshuizen HC, Forouhi NG, Wareham NJ, Halkjær J, Tjønneland A, Overvad K, Jakobsen MU, Boeing H, Buijsse B, Masala G, Palli D, Sørensen TIA, Saris WHM, Feskens EJM. Dietary fiber and subsequent changes in body weight and waist circumference in European men and women. Am J Clin Nutr 2010;91:329-36.