A new study has revealed that diet response is highly individualised, with the effects of diet decided as much at the genetic level as in regards to what is being eaten. The study, which was performed using mice, has big implications for both the individual seeking to eat as healthy as they can and for regulatory bodies providing dietary recommendations.

“There is an overgeneralization of health benefits or risks tied to certain diets,” said Dr William Barrington, a researcher from North Carolina State University who conducted this work in the laboratory of Dr David Threadgill at Texas A&M University.

“Our study showed that the impact of the diet is likely dependent on the genetic composition of the individual eating the diet, meaning that different individuals have different optimal diets.”

The scientists used four mouse strains, in order to properly model genetic variation, and fed them food equivalent to today’s Western diet, a traditional Japanese diet, a traditional Mediterranean diet, or a high fat, low carb Atkin’s-like diet. Some mice also received standard mouse chow as a control point of comparison. The mice were fed like this for six months and while they could eat as much as they wanted, their intake was monitored by the researchers.

Monitoring various health-related responses, the team found that the effects of each diet were highly dependent on the strain of mice. Mice eating the Western diet, for example, generally showed negative health effects, such as obesity and fatty liver disease, but the severity of these effects wildly varied across the different strains. Additionally, one of the strains seemed to be mostly resistant to the negative effects of this diet.

“Given the metabolic and genetic similarity of humans and mice, it is highly likely that the level of diversity of diet response seen in our study will also be observed in humans,” said Barrington. “Since there are different optimal diets for different individuals, this underscores the need for precision nutrition, which would identify optimal dietary patterns for each person.”

Given the study’s findings, we may be looking to a future where our diet is individually tailored to us based on certain genetic markers.

Barrington’s findings indicate that our approach to diet so far has been far too heavily generalised and we will in fact be better served by a case to case basis, identifying the genetic indicators that correspond to certain diets and eating accordingly.

While introducing a new layer of difficulty in the specification required, the findings may allow for dietary design that more efficiently combats negative health effects such as obesity.

“We’ve largely viewed diet the same way for the last 100 years – assuming that there is one optimal diet,” said Barrington. “Now that we’ve identified that this is likely not the case, I think that in the future we will be able to identify the genetic factors involved in the varying responses to diet and use those to predict diet response in humans.”