In the previous study, Ordovas, Corella and colleagues found men and women with the CC genotype had a statistically significant higher intake of fat than the TT and TC genotype groups. Additionally, CC carriers ate about 200 more calories per day and were about twice as likely to be obese.

The authors saw the same results for obesity prevalence within the CC genotype in the present study. "We saw a strong association between obesity and high-saturated fat intake, but again, there was no significant association between the two in CC carriers with low-saturated fat intake or in TT or TC carriers," Corella added.

Obesity was defined as BMI of 30 or greater. The researchers calculated BMI as weight in kilograms divided by height in meters squared. Dietary intake was measured by self-reported dietary questionnaires.

As in the general population, the majority of study participants possessed the TT and TC genotypes. Approximately 10 to 15 percent of the United States population is CC carriers, which was reflected in the FOS, GOLDN and Boston Puerto-Rican Study.

"Although CC carriers are only a small portion of the population, we believe the interaction we observed between saturated fat and BMI merits further investigation," Ordovas says. "There is a need to understand the mechanisms behind this particular diet-gene interaction and to find out whether other there are similar interactions in other genes that could factor in obesity prevention."

Source: Tufts University, Health Sciences