Currently, over one third of Canadian children and youth aged five to seventeen are overweight or obese. Childhood obesity leads to increased risks of co-morbidities such as type 2 diabetes, fatty liver disease, cardiovascular disease and certain types of cancers. Changes in the food supply have been linked to obesity and include a decrease in the intake of dietary fiber. Prebiotic fibers are a group of non-digestible carbohydrates that modulate the composition and actions of the gut microbiota and have been shown to reduce body fat and energy intake in overweight and obese adults. The investigators hypothesis is that prebiotic fiber intake in overweight and obese children will similarly result in improvements in body composition and reduced energy intake.

Obesity in the pediatric population is a primary public health concern given that overweight and obesity in childhood continues into adulthood. Consumption of high-fat, calorie-dense diets do not provide individuals with the suggested daily intake of many important nutrients. This is especially true for dietary fiber which has positive health benefits such as roles in weight management. A form of dietary fiber with links to obesity treatment/prevention is prebiotic fiber. In the gut, there are many bacteria which have been shown to affect a person's health depending on the type and number of each type of bacteria. The role of prebiotic fiber is to increase the number of beneficial bacteria which in turn promotes health. Studies in humans have shown that prebiotic fiber is effective at reducing body fat and food intake in overweight and obese adults. The aim of this study is to see if prebiotic fiber can provide the same benefits to overweight and obese children. Since weight management becomes increasingly difficult as a person ages, treatments that promote weight maintenance at an early age are critically needed.

Inclusion Criteria:

• Boys and girls between the ages of 7-12 years old
• BMI percentiles >85th percentile for their age and sex
• Tanner stage of ≤ 3, girls premenarche

Exclusion Criteria:

• Tanner stage of >3 or girls postmenarchal
• Use of antibiotics up to 3 months prior to study
• Regular prebiotic supplement and/or probiotic supplement use
• Subjects unable to provide consent (parental) or assent (child)