GENES AND BODY-FAT

This paper reviews recent data concerning the role of inherited differences in body fat content. The heritability of percent body fat or fat mass reaches about 25% of the age and gender adjusted phenotypic variance. One study has reported a significant major gene effect accounting for almost one half of the variance in body fat content. Experimental overfeeding studies suggest that body weight and fat gains are influenced by undefined genetic characteristics. Significant heritability estimates have been reported for major determinants of body fat content, including fat content of the diet, resting metabolic rate, thermic response to food, and level of habitual physical activity. Animal genetic studies and other experimental approaches indicate that the number of genes affecting body fat content, and associated with the susceptibility to obesity, is likely to be high. Currently available research strategies along with more extensive intermediate phenotyping will advance our knowledge about the genetic basis of human obesity. (C) 1993 Wiley-Liss, Inc.