Prince RL, Kuk JL, Ambler KA, Dhaliwal J, Ball GD. Predictors of metabolically healthy obesity in children. Diabetes Care. 2014 May;37(5):1462-8.

 Why do some obese youth remain healthy while others develop disease?

Despite the abundance of evidence demonstrating the negative consequences of excess weight, there are some individuals who do not have the common health conditions that are linked with obesity. These individuals who are healthy and obese are more commonly seen in youth, and reasons as to why they do not have these negative health problems are unclear. Also, what factors should be used to decide that they are ‘healthy’ are unclear.

In this study, we categorized 181 pediatric patients attending the weight management program at the Pediatric Centre for Weight and Health at the Stollery Children’s Hospital in Edmonton, Alberta as healthy or unhealthy. Healthy was defined using two commonly used definitions: 1) Insulin sensitivity alone; or 2) no traditional cardiovascular health risk factors (high blood pressure, blood fats or sugar). Healthy obese youth were compared on diet, physical activity and obesity factors.

Depending on the definition used, the prevalence of obesity was 21.5 to 31.5%. Even within this relatively homogeneous population or obese youth, individuals with high waist circumference were less likely to be considered ‘healthy’ by either definition. Youth that consumed less calories, whether in the form of fat, carbohydrate or protein were more likely to be considered ‘healthy’, whereas youth engaging in moderate or vigorous physical activity were more likely to be categorized as ‘healthy’. However, screen time was not different between obese youth who were or were not ‘healthy’.

“Our findings challenge the idea that all obese youth are ‘unhealthy’. However, our finding does suggest that there may be a limit to ‘healthy obesity’ as those within the upper levels of obesity were more likely to have these negative health conditions” says study co-author Jennifer Kuk, an Associate Professor in York University’s School of Kinesiology & Health Science. “Clearly, engaging in a healthy lifestyle with physical activity and moderation in diet are important for weight management, but may also be important for the maintenance of health in obesity. Given the difficulties in sustaining long term weight loss, the more realistic alternative may be to try to limit weight gain, while engaging in a healthy lifestyle.”

The study, “Predictors of metabolically healthy obesity in children and youth” appears in the May issue of Diabetes Care, published by the American Diabetes Association. It is co-authored by Rhiannon L. Prince, Kathryn A. Ambler, Jasmine Dhaliwal and Geoff D.C. Ball from the Alberta Health Services and the University of Alberta.