Here's some of the benefits science has discovered about intermittent fasting

The concept of intermittent fasting may seem scary at first. Going many hours without food? Not even a snack to tide you over? Whether you refer to it as time-restricted eating or IF, the practice of going for a block of time without sustenance — and doing that on a consistent basis for at least a few weeks — has inspired numerous researchers to investigate one big question: Does it really improve your health?

According to a number of studies, the answer seems to be yes. Although more research is needed to pin down all the physiological mechanisms that make this strategy beneficial, we've got a sampling of what researchers have discovered so far. Keep reading to discover the five potential benefits of intermittent fasting.

1. It May Help You Live Longer

Restrict your eating, lengthen your life? The evidence for the fountain-of-youth effect is promising. Researcher Mark Mattson, PhD, an adjunct professor of neuroscience at Johns Hopkins University School of Medicine in Baltimore, looked at numerous intermittent fasting plans and concluded that two in particular are especially effective: restricting your eating time to a six- to eight-hour window every day (so, only eating between 11 a.m. and 7 p.m., for example), or a technique called 5:2 fasting, that involves eating normally five days a week and then eating only one moderate-size meal two days a week.

Publishing the results in The New England Journal of Medicine in 2019, Mattson noted that people who followed these plans showed improvement in blood pressure regulation, resting heart rate, blood sugar regulation, inflammation, and overall resistance to stress. “Taken together, it’s not hard to see why results like that might lead to a longer lifespan,” he says. “The more that evidence like this builds up, the more it feels like a transition point for intermittent fasting from an interesting personal health strategy to one that may be added to medical school curricula alongside standard advice about healthy diets and exercise.”

2. It Helps Maintain Muscle Mass

For people who are carrying a significant amount of excess weight, simply losing pounds often results in health benefits. But a better weight loss strategy tends to be maintaining or increasing muscle mass and lowering body fat. Research shows this combination brings many advantages, including a lower risk of chronic diseases and better mobility as you age. Maintaining muscle as you age also helps ward off sarcopenia, which puts you at risk for various potentially fatal conditions, including falls.

Mattson says intermittent fasting can help because at a certain point, usually after several hours without food, the body stops relying on calories taken in through food and starts burning fat instead. Metabolic switching is the name of this process, and it can be a boon for reducing body fat overall. Studies have shown that intermittent fasting, especially time-restricted eating, spares muscle while burning fat.

3. It Boosts Heart Health in Many Ways

Thanks to improvements in blood pressure and blood sugar management (also known as insulin sensitivity), intermittent fasting can be beneficial for heart function, says Luiza Petre, MD, a cardiologist and assistant clinical professor of cardiology at Mount Sinai School of Medicine in New York, who practices intermittent fasting herself.

Research published in The American Journal of Medicine in 2021 found that time-restricted eating benefits heart health through multiple surprising mechanisms. For one, it tends to improve the body’s circadian rhythm, which in turn improves sleep. Considering that insomnia is strongly linked with higher blood pressure and heart disease risk, this is a major benefit for your ticker.

4. It Reduces Diabetes Risk and Fine-Tunes Hunger Signals

If you already have diabetes, it’s crucial to check with your doctor first before making a major change to your diet, including trying intermittent fasting. However, it may be worth having that conversation: Research published in the journal Clinical Diabetes and Endocrinology in 2021 found ample evidence that intermittent fasting can not only reduce body weight in people with type 2 diabetes, it also decreases fasting glucose, insulin resistance (where your body becomes numb to the effects of insulin), and levels of a hormone called leptin. It’s responsible for adjusting hunger based on how much energy you have stored.

When leptin production is working correctly, it tends to reduce hunger signals so you don’t overeat. That optimization can help regulate blood sugar, which leads to a range of effects like more energy and lower weight. For people with type 2 diabetes, it could also lead to less reliance on medications like insulin.

All of these advantages mean time-restricted eating may be helpful for reducing diabetes risk as well, especially if you’re in the prediabetes category, says Jason Fung, MD, author of The Complete Guide to Fasting. Of course, that also depends on what you’re eating during your feeding window, he says. “Intermittent fasting on its own can improve factors like insulin regulation, but if you’re eating highly processed, very high-calorie foods with little nutritional benefit, you’re not going to see many improvements from simply changing your eating window," he adds.

5. It Bolsters the Immune System

An interesting study published in Metabolism Open early in 2022 looked at intermittent fasters during the holy month of Ramadan — when practicing Muslims go without food from dawn to dusk — with an eye toward how it might affect the immune system and protect against COVID-19 infection. The researchers found that there were multiple mechanisms by which “fasting has the potential to optimize the immune system function...as it suppresses chronic inflammation and oxidative stress, improves metabolic profile and remodels the microbiome.” While these changes may make it easier for the body to ward off COVID infection, more targeted research is needed (in the meantime, all other necessary precautions should be taken). In addition, several studies have shown intermittent fasting can reduce levels of pro-inflammatory cytokines and the risk of inflammatory diseases, including heart disease, cancer and fatty liver disease, which is on the rise.

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