Genetics of obesity.

BACKGROUND: The prevalence and cost of overweight and obesity are projected to continue to rise in our current sedentary, energy-rich environment. The heritability of obesity is reported to be 40-80%.

OBJECTIVE: The objectives of this article are to review recent genetic discoveries about the basis of human obesity; describe familial or syndromic obesity, which is rare but presents early and should, if suspected, be referred for full specialist diagnosis of the underlying genetic disorder; and summarise immediate implications for general practice.

DISCUSSION: Increasingly, specialised genetic studies are helping to unravel the complex physiology underlying the regulation and control of body fatness. Rare but serious syndromic obesity can now be identified early in life. Possible targets for future drug treatment are currently being found and tested, offering hope for the future. Understanding the heritable nature of obesity should also help to relieve the blame and guilt from the professional's approach to current weight management.