Prebiotics are indigestible components of foods that promote the growth of specific bacteria in the colon. Supplementation with prebiotics can have a significant effect on BMI increases during puberty. A recent study showed that when calcium intake is adequate the improvement in BMI was even greater and the improvement was still measurable a year after the supplementation stopped.
Prebiotics are normally found in unprocessed carbohydrates including oats, soybeans, whole wheat and barley. Examples of prebiotics include Fructo-oligosaccharides (FOS), Inulin and Galacto-oligosaccharides (GOS). They are also available as food supplements.