A new study conducted by researchers at the University of New South Wales indicates that yo-yoing between eating well during the week and binging on junk food over the weekend is likely to be just as bad for your gut health as a consistent diet of junk. The team of researchers, led by Professor Margaret Morris, the Head of Pharmacology at UNSW, used rats to examine the impact of yo-yo dieting on gut microbiota. "The findings indicate that intermittent exposure to junk food three days a week is sufficient to extensively shift the gut microbiota towards the patten seen in obese rats consuming the diet continuously," said Morris, according to a press release.

The research team did a study comparing the abundance of microbiota in rats. The rats that were given constant access to both nutritious and non-nutritious food were compared to a group of rats who cycled between the two diets - healthy for four days and the remaining three days eating junk food - over the course of 16 weeks.

The results at the end of the 16 weeks indicated that rats on the cycled diet were 18 percent heavier than those on the healthy diet. The study also revealed that the cycled rats showed a diversity in food intake, consuming 30 percent more energy than the rats on a strictly healthy diet. When the cycled rats switched back to a healthy diet, they consumed half the amount of food and calories than a rat that regularly ate healthy.

"The study suggests certain gut microbiota, including Ruminococcus and Blautia, may be promising targets for future therapeutic strategies to treat metabolic disorder," said Morris. Though these findings are yet to be preformed on humans, the study is a strong indication that those people who have a healthy diet during the week and binge on the weekends are possibly undoing all of their hard work.

The findings were published in the journal Molecular Nutrition and Food Research.