A Banana a Day, Keeps the Belt Loops at Bay

Bananas are rich in inulin and resistant starch, which has prebiotic effects.

Scientists may have found a novel way to address childhood obesity: through the gut. Obviously. No really, a recently published study suggests that prebiotics, those nondigestible carbohydrates often confused for probiotics, may be one of the keys to fostering losses in body weight and body fat in overweight children.

Researchers from the University of Calgary recruited 42 children aged 7 to 12 who were classified as obese to participate in a double-blind placebo-controlled trial involving the effects of prebiotic fiber on various metrics of health. The participants were randomly assigned to the control group, which was provided a maltodextrin placebo, or the trial group, which was given oligofructose-enriched inulin, a common prebiotic combination of two substances found naturally in many conventional foods, such as bananas and garlic. The supplements consisted of a powdered fiber that participants were asked to mix with water and take once daily. Otherwise, participants were asked to maintain their normal food and physical activity routines over 16 weeks. At the beginning of the trial, and every four weeks thereafter, various health metrics were collected, including fat and lean muscle mass measured using dual-energy x-ray absorptiometry. At the conclusion of the trial, children in the control group saw an average 0.5% increase in bodyweight and 0.05% increase in fat mass, while the trial group experienced nearly 3% decreases in both weight and body fat. The trial group also experienced significant improvements in blood glucose regulation and serum cholesterol levels. Furthermore, the trial group showed distinct and statistically significant alterations in gut microbiota population compared to the placebo group. Although the study was focused on preadolescent children, researchers found no reason why the findings would not be generalizable across all age groups.

This latest finding isn’t surprising when evaluated in context with the rest of the recent research evaluating the influence of gut bacterial population on obesity. Metagenomic and metabolomic studies have shown that a strong population of healthy microbiota in the gut, due to a diet focused on whole unprocessed and high fiber foods, may help modulate energy balance from both sides of the equation: by more effectively converting food into energy and increasing energy expenditure through increased fatty acid oxidation. It is also believed that gut bacteria may influence the chronic inflammatory state of obesity by regulating the level of endotoxins in our blood. Other studies have provided further evidence that gut microbiota is a cause and not a consequence of obesity or altered dietary habits. In one animal study, researchers actually transplanted the caecal microbiota from lean and obese mice into the gut of germ-free mice and found that the mice hosting the “obese microbiota” showed several markers of decreased metabolic efficiency and ultimately gained weight while the animals with the “lean microbiota” actually lost weight despite the exact same caloric intake and physical activity regimen. In human studies, researchers have found that a lack of gut bacterial diversity was highly associated with obesity, including one study that examined twins. While the unfortunate truth is that the composition of our gut microbiota is highly genetic, numerous human trials have shown that healthy whole food diets and probiotic and prebiotic supplementation can positively influence gut bacterial colonization. Possibly even more interesting, maternal and paternal diets have been shown to influence the gut microbiota of their unborn children. Even more reason for parents to eat healthy and include plenty of fiber and fermented foods in their diet.

There is no doubt about it, prebiotics can be beneficial to health and weight management, especially in children. But as usual, the primary takeaway from this latest research is the importance of a whole food diet. While supplementation is always a great alternative, the best sources of fat-fighting prebiotics are densely fibrous foods, such as leafy greens, asparagus, onions, and bananas. For the size and composition of your gut, and that of your growing children, stick to the periphery of the grocery store on your next shopping trip.

Dr. Damian Rodriguez is the health and exercise scientist for doTERRA International, LLC. He holds a doctorate in health science, a master’s degree in exercise physiology, and countless professional certifications. He has spent most of his life researching nutrition, exercise, and the lifestyle behaviors associated with optimal health. Along with his passion for health, as someone who lives with Asperger’s Syndrome, he is also involved in bringing awareness to autism spectrum disorders. There are varying opinions about many health and fitness topics. His opinions are his own and not necessarily that of doTERRA International, LLC. Consult your healthcare provider before making any changes to diet and exercise.