After only five days of eating a high fat diet, the way in which the body’s muscle processes nutrients changes, according to a study by Virginia Tech – published in the online version of the journal Obesity. This is thought to be the first study to find that a change in metabolism happens so quickly after adopting an unhealthy diet, with these shifts increasing the risk of diabetes and other diseases.

Healthy college-age students were fed a fat-laden diet during the study. The diet included sausage biscuits, macaroni and cheese, plus food cooked with lots of butter to increase the percentage of their daily fat intake. A normal diet is made up of about 30 per cent fat and the participants in this study had high fat diets of 55 per cent fat. The students’ calorie intake remained the same as it was prior to the high fat diet.

Muscle samples were then collected because, as the authors of the study say, the body’s muscle is a major clearing house for glucose in the blood – which appears after food is eaten. Muscle may break glucose down for energy or store it for later use. Muscle makes up about 30 per cent of our body weight and it is an important site for glucose metabolism, however, if normal metabolism is altered it can have dire consequences and lead to health issues.

The researchers found that the muscles’ ability to break down glucose after a meal is disrupted after five days of eating a high fat diet, which could lead to the body’s inability to respond to insulin – a risk factor for the development of diabetes and other diseases.

“This [study] shows that our bodies can respond dramatically to changes in diet in a shorter timeframe than we have previously thought,” said Matt Hulver, an associate professor of human nutrition, foods and exercise at the Virginia Tech College of Agriculture and Life Sciences. “If you think about it, five days is a very short time. There are plenty of times when we all eat fatty foods for a few day, be it the holidays, vacations, or other celebrations. But this research shows that those high-fat diets can change a person’s normal metabolism in a very short timeframe.”

While the student participants did not gain weight or show any signs of insulin resistance, the researchers are now interested in examining how these short-term changes in the muscle can adversely affect the body in the long run and how quickly these changes can be reversed once someone returns to a low fat diet.