What’s not to love about a cheat day? You can ditch your diet, eat all the chocolate chip cookies you want, and boost your metabolism. Right?
Wrong, says Michael Roussell, Ph.D., “Overeating simply isn’t going to enhance the rate you lose fat.”
Roussell acknowledges there are people who maintain low body-fat percentages even as they regularly indulge in daylong cupcake benders. “But for every one of those people, I could show you five others that only allow themselves just five to six cheat days per year in order to maintain single-digit body fat levels,” he says.
To step back, the idea is that a big cheat meal—or even an entire cheat day—fixes the decrease in your metabolic rate that normally occurs with dieting. One problem: That’s not what happens when scientists study the phenomenon.
For example, in a 2006 study, researchers at the Mayo Clinic had study participants overeat by 1,000 calories a day. After seven days of binging, the subjects’ average metabolic rate increased by a whopping 18 calories. (Note sarcasm.) You don’t need your Ph.D. in nutrition to realize that eating an extra 1000 calories to burn an additional 18 isn’t a formula for fat loss.
“This is just one study, but there are plenty of examples and the punch line is always the same: You never end up burning more calories than you consume,” says Roussell. “Any increases in your metabolic rate are temporary at best, and never enough to produce a noticeable effect.”
Roussell does advocate for having the occasional “discretionary meal” when dieting, but with the reminder that overdoing it will just slow your progress.
So if cheat days don’t boost your metabolism, then what does? “Exercise,” says Roussell.
“Lifting weights, specifically, will have the biggest impact on increasing your metabolism,” he says. What’s more, getting enough sleep and trying to maintain low levels of stress can also help keep your metabolism revving.
By Danielle Zickl