Dietary fiber from plant-based foods such as fruits, vegetables, whole grains, and legumes promotes gastrointestinal health, helps lower blood cholesterol levels, and may reduce the risk of developing cardiovascular disease and diabetes. High-fiber diets have also been associated with weight maintenance and weight loss. Inulin is a naturally occurring soluble fiber that is added to an increasing number of processed foods in order to increase dietary fiber, replace fat, and add mild sweetness.
A recent study (1) investigated the effect of inulin on hunger, fullness (satiety), and the amount of food consumed at the next meal. Each of 38 participants completed six different testing conditions: high-calorie yogurt drink with inulin, high-calorie yogurt drink without inulin, low-calorie yogurt drink with inulin, low-calorie yogurt drink without inulin, orange juice with equal calories to low-calorie yogurt drink, and no drink. For each testing condition, participants consumed the beverage in the morning; rated their hunger, fullness, thirst, nausea, and desire to eat every 20 minutes for 2 ½ hours; then ate as much of the served lunch meal as they desired.
The researchers found that all of the yogurt drinks suppressed hunger more strongly than an equal volume of orange juice. The high-calorie yogurt drinks suppressed hunger the strongest, but the low-calorie yogurt drink with added inulin suppressed hunger as well as the high-calorie yogurt drink without inulin. The results suggest that six grams of added inulin can be as filling as 260 calories. This study supports the hypothesis that dietary fiber such as inulin plays a role in weight management or weight loss by helping control food intake.
Perrigue MM, Monsivais P, Drewnowski A. Added soluble fiber enhances the satiating power of low-energy-density liquid yogurts. J Am Diet Assoc 2009;109:1862-8.