While the benefits of intermittent fasting for weight loss are pretty well known, restricting your eating to set time periods can do much more than just trim your waistline. Intermittent fasting can also trigger a range of other benefits, including increased stress resistance, longer lifespan, and a lowered risk of obesity and cancer, according to a new study from researchers at Johns Hopkins University. The study was published yesterday in The New England Journal of Medicine.
“We are at a transition point where we could soon consider adding information about intermittent fasting to medical school curricula alongside standard advice about healthy diets and exercise,” neuroscientist Mark Mattson, one of the authors of the study, said in a Johns Hopkins press release.
By analyzing several previous studies of people and animals on a time-restricted diet, the researchers found mounting evidence that intermittent fasting can have a powerful effect on overall health. While individual fasting regimens vary, the meal plans the researchers studied generally fell into two categories: eating only in a six to eight hour window every day, and eating only one modest meal on two days of the week, USA Today reports. (We’d argue that there’s a third way to fast as well.) The researchers found positive health effects with both methods.
First, the new study shows that fasting could provide a boost for heart health. Mattson told the Johns Hopkins blog that previous studies already show fasting can reduce stress, improve blood sugar regulation, and reduce inflammation. In addition, four separate studies on humans and animals found that intermittent fasting helped lower blood pressure, blood lipid levels, and resting heart rates—all key improvements in cardiac health.
Fasting could also help counteract obesity and diabetes. Another two studies in the U.K. followed 100 overweight women and compared fasting with traditional calorie counting. Women who fasted lost the same amount of weight as those who counted calories, but had less belly fat and improved insulin sensitivity.
There’s even evidence that fasting could help our brains, too. A clinical trial in Canada followed 220 healthy adults on a calorie-restricted diet for two years. At the end of the trial period, cognitive tests showed that their memory had improved.
Although the way intermittent fasting influences the body is still poorly understood, Mattson believes it’s related to how our cells create energy. Fasting triggers metabolic switching, a cellular adaptation to food scarcity: When the body uses up its reserves of easily accessible insulin derived from food, it switches to burning fats for energy. That switch in the body’s fuel source—previously touted for its weight loss benefits—could also trigger fasting’s other important health benefits.
Want to feel those benefits yourself? Start off slowly, Mattson said in the press release, and give your body time to adjust.
“Feeling hungry and irritable is common initially,” he said, “and usually passes after two weeks to a month as the body and brain become accustomed to the new habit.”
Gradually increasing the length and frequency of your fasts over a few months will make it easier, Mattson advises. You can trust him on that—besides studying intermittent fasting for decades, he’s been doing it himself for 20 years.