The Burrill Report



Why some people seem to eat whatever they want without gaining any weight while others seem to gain weight merely by looking at fattening foods may come down to biology. Researchers in the United States, Canada, and Australia report in the July 2010 issue of Genetics that genes interacting with diet, rather than diet alone, are the main cause of variation in metabolic traits, such as body weight. The study involving fruit flies helps explain why some diets work better for some people than others, and suggests that future diets should be tailored to an individual's genes rather than to their physical appearance.

“There is no one-size-fits all solution to the diseases of obesity and type-2 diabetes,” says Laura Reed, lead investigator in the study and a genetics researcher at North Carolina State University. “Each person has a unique set of genetic and environmental factors contributing to his or her metabolic health, and as a society, we should stop looking for a panacea and start accepting that this is a complex problem that may have a different solution for each individual.”

The scientists studied 146 different genetic lines of fruit flies that were fed four different diets: nutritionally balanced, low calorie, high sugar, and high fat. Researchers then measured a variety of metabolic traits, including body weight, in each group. Flies in some of the genetic lines were highly sensitive to their diets, as reflected by changes in body weight, while flies of other lines showed no change in weight across diets. The scientists were able to ascertain what portion of the total variation in the metabolic traits was determined by genetics alone, by diet alone, or by the interaction between genotype and diet.

Results showed that diet alone made a small contribution to the total variation, while genotype and genotype interactions with diet made very large contributions. The study strongly suggests that some individuals can benefit from altering their dietary habits, while the same changes for others will have virtually no effect.

The research confirms the one-size-fits-all approach offered by many diet programs does not work the same for all people. The fact remains that people must deal with their individual genetic makeup and tailor their diet to work for them.



July 28, 2010
http://www.burrillreport.com/article-one_size_does_not_fit_all.html