Intermittent fasting is a dietary approach that involves cycling between periods of fasting and eating on a regular schedule. Research has suggested that this method can assist with weight management and potentially prevent or even reverse certain illnesses. But what exactly is intermittent fasting, and is it safe?
Intermittent fasting is a way of eating that focuses on when you eat, rather than what you eat. The approach involves restricting food intake to a specific time period each day, with research indicating that fasting for a set number of hours per day or eating just one meal a few days each week may have health benefits.
According to Johns Hopkins neuroscientist Mark Mattson, our bodies have adapted to going extended periods without food, even several days or longer. In the past, before farming, humans were hunters and gatherers who evolved to survive for prolonged periods without eating. Mattson's research has shown that after hours without food, the body exhausts its sugar stores and starts burning fat. This process is referred to as metabolic switching.
The various intermittent fasting plans have different schedules. One such schedule is daily restriction, limiting daily eating to a specific six- to eight-hour period each day. The 5:2 approach involves eating regularly for five days a week and limiting yourself to one 500-600 calorie meal on two days.
Experts recommend consulting your doctor before attempting intermittent fasting. It's critical to note that longer periods without food, such as 24-, 36-, 48-, and 72-hour fasting periods, may not be safe and can be dangerous.
Intermittent fasting can take a few weeks for the body to adjust, and you may feel hungry or cranky initially. However, Mattson's research indicates that research subjects who make it through the adjustment period tend to stick with the plan because they notice feeling better.
During the fasting periods, drinking water and zero-calorie beverages like black coffee and tea are allowed. Eating healthily is also critical. Research suggests that eating high-calorie junk food during feeding times won't assist with weight loss or promote health.
Intermittent fasting has been associated with several health benefits, including improved heart health, physical performance, and type 2 diabetes and obesity prevention. Intermittent fasting has also been shown to protect organs against chronic diseases like type 2 diabetes, heart disease, and even certain cancers. Studies have found that it can improve thinking and memory, reduce tissue damage, and provide several other health benefits.
Before trying intermittent fasting, consult with your doctor, particularly if you have a history of eating disorders or are under 18, pregnant, breastfeeding, or have type 1 diabetes who take insulin. If done safely, intermittent fasting can be a lifelong lifestyle change with several benefits.