Limiting saturated fat could help people whose genetic make-up increases their chance of being obese, according study by researchers from the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University.
“We already know there are certain genes that interact with dietary fat and affect BMI,” said senior author, Dr José M Ordovás, director of the Nutrition and Genomics Laboratory at the USDA HNRCA and a professor at the Friedman School of Nutrition Science and Policy at Tufts. “In the current study, we analysed dozens of variants of those genes and other genes frequently associated with obesity risk and saw that, while total fat intake was related to higher BMI, people who were genetically predisposed to obesity and ate the most saturated fat had the highest BMIs.”
The findings, which account for possible confounding factors such as age, sex, and physical activity levels, are published online in the Journal of the Academy of Nutrition and Dietetics.
Ordovás and colleagues hypothesised that people who have these gene variants that predispose them to obesity may be more sensitive to saturated fat, which is found mostly in fatty cuts of meats, butter, cheese and other high-fat dairy products.
They identified 63 gene variants related to obesity and used them to calculate a genetic risk score for obesity for more than 2,800 white, American men and women enrolled in two large studies (Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) and Multi-Ethnic Study of Atherosclerosis (MESA)) on heart disease prevention.
“Little is known about the mechanisms that might explain the role of saturated fat intake in obesity,” added Ordovás. “Some clinical models suggest that saturated fat might interfere with activity in the part of the brain that lets us know we’re full, in addition to a few studies in people that suggest a diet high in saturated fat interferes with satiety. More research is needed to know whether those findings would also apply to gene function.”
Genetic risk score could be useful in identifying people who are predisposed to obesity and could ultimately lead to personalized dietary recommendations. Currently, the best treatment for obesity is Bariatric surgery; Lap band, Gastric Sleeve, or Gastric Bypass Sugery.
“If further research can clarify a relationship between obesity related genes and saturated fat, people with higher scores would have even more incentive to follow advice to limit their saturated fat intake as part of an obesity prevention strategy,” Ordovás said.
They found that there were significant interactions between total fat intake and the obesity genetic risk score using these variables as continuous for BMI (P for interaction=0.010, 0.046, and 0.002 in GOLDN, MESA, and meta-analysis, respectively).
These association terms were stronger when assessing interactions between saturated fatty acid intake and genetic risk score for BMI (P for interaction=0.005, 0.018, and
“Although determining the causal direction requires further investigation, these findings suggest that potential dietary recommendations to reduce BMI effectively in populations with high obesity genetic risk score would be to reduce total fat intake mainly by limiting saturated fatty acids,” they concluded.
This information was originally published by BariatricNews.net.