It’s a dieting scenario many of us are familiar with – sticking to healthy eating during the week before going all out on a junk food binge as soon as Saturday arrives.
But now experts have warned that this yo-yo dieting can be just as dangerous as a consistent diet of calorific fast food.
A new study, published in the Molecular Nutrition and Food Research journal, used rats as subjects to examine the effect this yo-yo dieting can have on the gut’s organisms (microbiota).
There are believed to be up to 100 trillion microbial cells that make up the human gut, which can influence metabolism, immune function and nutrition – as well as mental health, according to new and growing evidence.
However, if the microbiota are disrupted, it can lead to conditions such as inflammatory bowel disease and obesity.
Scientists conducting this study used microbiota from an obese human and transferred it to a lean mouse, which led to the mouse becoming obese.
In addition, high-fat diets can lead to a major shift in microbiota – associated with weight gain and added fat.
In order to properly gauge the reaction of these diets, the scientists split the rats into groups – one were given a healthy diet, one a junk food diet and one a mixture of the two, having healthy food for four days and junk food for three, over the span of 16 weeks.
The rodents that were on the cyclical diets consumed three times as much energy as those eating solely healthy food.
As well as this, when they returned to the healthy diet, they ended up consuming half as much nutritious food as those on the healthy diet consistently.
The end of the study showed that the rats on the cyclical diet were 18 per cent heavier than the ones on a healthy diet only, but were still lighter than those having junk food all the time.
Looking at the microbiota profiles though, the rats on the junk food diet and the cyclical one had their gut profile shifted.
Therefore those consuming junk food all the time and those having it only three days of the week suffered similar, negative, changes to their guts.
The results of the study show that it’s the same when applied to humans, with binge eating at the weekend having a similar effect to eating junk food all the time.
However, experts reassure that anyone eating unprocessed foods and an unhealthy diet can quickly change their ways – and their gut profile – to become healthier for the future.