Diet Fail: Genetics Explain Why Your Friend Lost Weight on a Diet And You Didn't

Some people actually fare better on higher fat diets while others put on the pounds on these eating plans. Scott Olson/Getty Images

Traditional dieting plans advise people to eat less and move more. The science of weight loss is increasingly showing that things just aren't that simple as genetics plays a role, too.

Related: Why Are Some People Fat? One Gene, Not Diet, Might Be the Problem

New research from scientists at Texas A&M University found that a standard diet doesn't work for everyone, in a study in animals. Published in the research journal Genetics, the team looked at how five different diets impacted the animals' health during the course of six months. According to a release, creatures in the same genetic group had virtually no variance while those in different groups had genes that would indicate they were from different families.

The diets were picked to reflect our own and included American (high in fat and carbs), Mediterranean (wheat and red wine-based), Japanese (heavy on the rice and green tea), ketogenic (low in carbs, high in fat) and Atkins (high in fat and protein, low on carbs). The team also used a control diet to compare against.

Researchers looked for evidence of metabolic syndrome, a compilation of factors that increase your chances of heart disease, which includes things like high blood pressure and cholesterol. Behavioral changes, such as appetite and activity level, were also studied.

Unsurprisingly, the "healthier diets," such as the Japanese-based eating plan, worked for most of the animals. However, one genetic type actually suffered from consuming all that rice and tea.

"The fourth strain, which performed just fine on all of the other diets, did terrible on this diet, with increased fat in the liver and markings of liver damage," William Barrington, lead study author, said in a statement.

The Atkins diet also wasn't for everyone and the research that two of the genetic types had some unpleasant consequences.

"One became very obese, with fatty livers and high cholesterol," Barrington said. The other accumulated more fat and essentially became a couch potato. "This equates to what we call 'skinny-fat' in humans, in which someone looks to be a healthy weight but actually has a high percentage of body fat," he said.

While the researcher was hoping to find the best overall diet, the results showed that there may not be just one optimal way of eating as what keeps one person svelte might cause another to gain weight.

This is just the latest in a growing body of research showing how our genes might determine whether we're slim or constantly struggling to maintain our dress size. Of course, there's still a lot of research that needs to be done, but the present findings have spurred a new industry of customized diet plans, like Fitness Genes, which analyzes DNA and sends back a fitness and eating plan personalized for your body.

Now, if only science could make weight loss without dieting possible.