It stands to reason that exercise makes us hungrier. We’re burning more calories, so we need to take more in, right? Well, there is a relationship between exercise and what you eat, but it’s more complicated than that.
Sally Squires, who writes the Lean Plate Club™ blog, told WTOP that researchers had the same common-sense assumption about exercising and appetite, until they performed a study on overweight men.
It turned out that “the numbers didn’t track that way,” Squires said.
Two factors did matter, though: 1) the intensity of the exercise and 2) when you exercise.
“If you exercise within an hour of eating a meal, you’re much less likely to eat more calories,” she said. Those who exercised an hour before a meal not only ate fewer calories at that meal, but they didn’t negate that by eating more later: “They were less hungry throughout the day.”
The men showed less craving for salty foods. And those who engaged in high-intensity exercise were less hungry the next day as well.
It turns out, Squires said, that exercise does more than that: It can change the composition of the bacteria in your gut.
“Exercise does help change some of the microbiome,” she said, comparing it to the kind of change you get from the healthy bacteria in yogurt. (She also said “We are actually more bacteria than we are human cells,” but we’ll leave that here for now.)
“Even older people who exercise, it seems to change their gut bacteria, and that may help or moderate things like Alzheimer’s,” Squires said. It’s not definitive, but “this is a new line of investigation that scientists are going to continue to pursue.”
She added, “This is why it’s really important for all of us to continue to remain active.”