Heritability of common obesity

Abstract

There is a global rise in prevalence of obesity, which will be followed by a rise in prevalence of cardiovascular disease, metabolic syndrome and cancer. Understanding why individuals fail to balance their energy intake and expenditure is a key point in bringing this “pandemic” to a halt. Twin studies on obesity show that 50 – 90% of variance in body mass index (BMI) is explained by genetic factors. This also holds true for food choice and behaviour like cognitive restraint, emotional eating and uncontrolled eating. The results are confirmed by experimental studies testing the response to overfeeding or dieting; change in bodyweight differs between twins but shows resemblance within twin pairs. The genes underlying this genetic contribution to obesity can be identified via genome wide and candidate gene study approaches. The most promising candidates include genes involved in metabolic efficiency as well as genes influencing behaviour and brain function, with the systems being closely interlinked. Understanding this underlying pathophysiology will improve future treatment for obesity.