Oh, weekend. You fleeting, merciless creature. Forever tempting us with promises of good times and impunity, only to leave us chewed up and spit out on Monday morning, wondering how it’s even possible to feel more tired after two days of “rest.”
And while Monday mornings can be tough for most people who let themselves go on the weekend, they may be even harder on 100 trillion or so microbial cells in the human gut which help regulate metabolism, nutrition, and immune function.
Videos by VICE
That’s according to a new study published in the journal Molecular Nutrition and Food Research, which suggests that substituting regular junk food consumption with weekend binges is just as unhealthy, at least as far as the gut is concerned.
Researchers were able to quantify their results by comparing the amount of gut microbiota in rats who had continuous access to either a healthy diet, junk food, or a third group which cycled between healthy food for four days and junk for three.
After 16 weeks, the rats on the cycled diet turned out to be 18 percent heavier than those on the purely healthy diet. More interestingly, the researchers also found the microbiota of cycled rats was almost indistinguishable from rats fed a constant diet of junk, with both groups’ microbiota significantly different from those in the rats fed a healthy diet.
The study was headed by University of New South Wales pharmacologist Margaret Morris who said that her research is the first to compare regular junk food intake with intermittent binges.
“The findings indicate that intermittent exposure to junk food three days a week is sufficient to extensively shift the gut microbiota towards the pattern seen in obese rats consuming the diet continuously,” she said in a press release. “A reduction in the diversity of the gut’s microbiota and a loss of some of the beneficial biota is clearly not a good thing for health.”
Even though the experiment in this case was limited to rats, the researchers also warn that their findings could have important implications for humans who delay gratification until the weekend. “While these findings are yet to be replicated in humans, those who are strict with their diet during the week may be undoing all their good work by hitting the junk food over the weekend.”
Morris also argued that her research could lead to more effective treatment of human disorders. “The study suggests certain gut microbiota, including Ruminococcus and Blautia, may be promising targets for future therapeutic strategies to treat metabolic disorders,” Professor Morris said, adding that the team’s results are especially significant “given the current obesity epidemic and the prevalence of yo-yo dieting in Western countries.”
So next time you wake up on a Monday morning feeling bloated, lethargic, and a little guilty, your gut feeling is probably right.