Too much fat and sugar as a kid can have long-term health effects, study finds

Eating too much fat and sugar as a child can alter your microbiome for years, even if you adopt a healthy lifestyle later, a new study on mice suggests.

The study, by researchers at the University of California Riverside, is one of the first “to show a significant decrease in the total number and diversity of gut bacteria in mature mice fed an unhealthy diet as juveniles,” the scientists wrote.

“We studied mice, but the effect we observed is equivalent to kids having a Western diet, high in fat and sugar and their gut microbiome still being affected up to six years after puberty,” UCR evolutionary physiologist Theodore Garland said.

Your microbiome refers to the bacteria — as well as fungi, parasites and viruses — that live on and inside a person or animal. Most are beneficial, “stimulating the immune system, breaking down food and helping synthesize key vitamins,” the researchers wrote.

When you’re healthy, there is a balance of good and bad organisms in your microbiome. This balance can be disturbed, however, by antibiotics, illness or an unhealthy diet, leaving the body susceptible to disease.

For this study, published in the Journal of Experimental Biology, Garland and his team divided a group of mice into four groups. Half were fed the standard, “healthy’ diet, and half received the less healthy “Western” diet. Half had access to an exercise wheel.

After three weeks, all the mice were returned to how they normally would be kept in a lab — a standard diet and no exercise. They stayed this way for 14 weeks when the scientists checked the diversity and abundance of bacteria in them.

They found that Muribaculum bacteria increased in mice fed a standard diet who had access to a running wheel and decreased in mice on a high-fat diet, whether they had exercise or not.

Researchers wrote this species of bacteria, and the family of bacteria it belongs to, might influence the amount of energy available to its host.

Garland and his team found that, for children, eating a Western diet high is fat and sugar had a longer-lasting effect on the microbiome than exercise did.

The takeaway, Garland said, is essentially, “You are not only what you eat, but what you ate as a child!”