Carbohydrates: friend or foe of obesity and its complications?

With more than 650 million patients worldwide and a prevalence that will only increase further, obesity has become one of the biggest health-threats of the 21st century. Obesity is such a big problem because it induces a systemic inflammation that causes a lot of co-morbidities including cardiovascular disease and cancer. The biggest risk factor for obesity and obesity-associated inflammation is a western diet, high in fat and carbohydrates. However, the exact role of carbohydrates or fats in this inflammation, is not known yet. Therefore, the aim of this study was to investigate the effect of macronutrient composition on obesity and its complications in a murine model. Male, C57BL/6JRj mice were fed a diet high in fat, sucrose, fructose, sucrose and fructose, starch, a western diet or a control diet during 15 weeks. We demonstrated that a sucrose-rich- and high-starch diet induced less obesity, a better metabolic profile, less adipose tissue (AT) inflammation and better intestinal integrity than a western diet. Based on these data, we performed an intervention study to reduce the metabolic risk after mice were already obese. To this end, obese mice were put on (i) a caloric restriction (CR), (ii) change of diet composition and/or (iii) prebiotic supplementation. (i) To investigate whether there is a diet-dependent effect upon CR, mice wer subjected to a CR of 30% on either a western diet, a sucrose-rich diet or a high-starch diet. CR induced weight loss and decreased both metabolic abnormalities and AT- inflammation, regardless of macronutrient composition. (ii) Even without CR, switching obese mice to a sucrose-rich diet induced weight loss and decreased AT-inflammation and metabolic aberrations. (iii) Strikingly, prebiotic supplementation did not exert any beneficial effects. In conclusion, we demonstrated that a sucrose-rich or high-starch diet induces less obesity and obesity-associated complications. Moreover, switching obese mice to a sucrose-rich diet elicits weight loss and decreases obesity-induced metabolic complications, highlighting the potential of carbohydrates to treat obesity.status: accepte