More Than 70% Fat Differences Could Be Genetics
The researchers found that food intake correlated with body weight and lean mass. However, intake levels didn't account for the body fat changes seen with the high-fat, high-sugar diet. The investigators estimated that more than 70% of these body fat differences could be attributed to genetics.
To identify specific regions associated with obesity, the scientists performed a genome-wide analysis of about 100,000 genetic variations, or single nucleotide polymorphisms (SNPs). They found 11 regions that were associated with obesity. The regions contain several genes with known links to fat biology and metabolism in mice. Some have been linked to obesity in humans as well.
The researchers also analyzed gut microbe populations. They found that some mouse strains had large microbial shifts after eating the high-fat, high-sugar diet. Other strains of mice, however, showed little fluctuation. This finding shows that genetics strongly influences changes in gut microbes in response to diet.