Slacking off on weekends isn’t a good idea – it’s almost as bad for the microbiota as a bad diet all week.
Spending the weekend in front of the television, sweets and packets of crisps available: this is a ritual that many French people follow. Even some who the rest of the week comply with a more strict lifestyle. Those who hoped to avoid damage in this way may be disappointed. According to a study, published in Molecular Nutrition and Food Research and carried out on rats, three days of junk food is enough to unbalance the intestinal flora.
18% heavier
For 16 weeks, the researchers tested 3 types of diets: healthy food, foods with the wrong nutrient profile, and a mixture of the two – 4 days of healthy eating and 3 days of junk food. The last solution does not prove to be more beneficial than the second.
At the end of the research, rats on a cyclic diet were 18% heavier than those on a healthy diet. Their levels of leptin and insulin, two markers of metabolic health, fall halfway between the two groups. But the microbiota of animals that “alternated” the two types of food was not significantly different from that of animals that ate poorly all week.
More energy consumed
Yo-yoing between two types of food is therefore as bad for the intestines as permanent junk food. More worrying: it seems to boost food consumption: “alternating” rats absorb 30% more energy than their “strict” counterparts, when they are fed healthy foods.
“A decrease in diversity in the intestinal microbiota, and the loss of some of the beneficial cells is clearly not a good thing for health,” underlines Professor Margaret Morris, who signs this work. These results have yet to be replicated in humans, but those who are strict about their diet during the week should continue their efforts by eliminating junk food from their weekend. “
If these results are confirmed, they also open the way for a therapeutic intervention, which would target certain intestinal bacteria, such as Ruminococcus and Blautia.
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