Intentionally skipping or delaying meals, known as fasting, is an unusual practice for many people, but it’s gaining popularity as a way to prevent disease and maintain a healthy body weight. Proponents of intermittent fasting believe it’s better for your health to constrain your eating to just a portion of the day, allowing your body to go stretches of 12 hours or more without food.
Intermittent fasting is not a diet, but a method of scheduling your meals to optimize how your body uses nutrients. This pattern of eating doesn’t change the total number of calories you consume each day, but alters the frequency with which you eat these calories.
Maxine Barish-Wreden, M.D., a complementary and integrative medicine physician with the Sutter Medical Foundation, says doctors and researchers are realizing that our current eating patterns are contributing to the health epidemics of obesity, metabolic syndrome and diabetes. She says intermittent fasting offers the opportunity to eat as our ancestors did, without excessive amounts of carbohydrates and sugars.
“Human beings used to eat when the hunting was good. When it wasn’t, they might not have eaten for days,” Dr. Barish-Wreden says. “Our bodies are meant to have periods of time when we don’t eat so we can heal and regenerate.”
Ronesh Sinha, M.D., an internal medicine specialist with the Palo Alto Medical Foundation, agrees and notes that intermittent fasting as a cultural or religious practice has been around for thousands of years.
“In many cultures, fasting is a selfless act devoted to some higher spirit,” Dr. Sinha says. “Once a person is in the habit of intermittent fasting, he often feels purified and experiences improved cognitive performance. It’s a way to clear the mind and renew the body.”
In addition to mind-body benefits, intermittent fasting has been shown to curb sugar cravings, reduce overeating, improve gut function and offer potential protection against various types of cancer. However, these health benefits do not occur during extreme fasts where people go for multiple days without eating. This can lead to nutritional deficiencies and chronic health problems.