8 Types of Intermittent Fasting

Woman standing on scale, trying to determine her weight.

Intermittent fasting (IF), which is also called time-restricted eating, occurs when you limit eating to a short window of time and then eat nothing and fast for another set duration before eating again. Research shows that this approach, like other methods of calorie-restricted dieting, can work if you’re overweight and trying to lose weight.

Fasting approaches that restrict eating during a specific timeframe are popular and considered easier to follow than many traditional diets — especially when the fasting window encompasses nighttime hours when you’re asleep and not obsessing about food cravings and hunger pangs.

Other fasting plans focus on calorie restriction or eating only low-calorie foods such as fruits, vegetables, juices and soups during that fasting timeframe.

Here’s an overview of IF approaches. (Always talk to your doctor before making major changes to your diet.)

Alternate day fasting (ADF)
ADF is a favored approach involving calorie restriction versus full calorie elimination on fasting days. It entails fasting every other day by restricting calories to only 30% of your regular calorie intake on fasting days and reverting to the full recommended calories for your age, gender and weight goal on non-fasting days.

Eat-Stop-Eat (ESE)
Often used as a reset fast, ESE is a 24-hour fast free from calories done once or twice a week.

The 5:2 approach requires fasting for two days out of every seven by only consuming 500-600 calories on fasting days.

The 16/8 method, also known as the Leangains diet, involves fasting for 16 hours and eating only within an eight-hour timeframe. Most choose noon to 8 p.m. as their eating window so a large part of their fasting period is during sleep.

Water fasting
As the name suggests, this approach entails drinking only water for set amounts of time. While considered popular as part of a detox diet — targeted to rid the body of harmful toxins — detox diets don’t actually do much and can be dangerous.

Juice fasts
Juice fasts or ‘juicing’ entails only drinking fruit or vegetable juice during a predetermined fast time. It is not recommended if you are managing or at risk for diabetes as carbohydrate sugars in natural juices can impact blood glucose levels.

Partial fasting
This approach eliminates certain foods or drinks from your regular diet at frequency for a set amount of time, such as a couple of days, weeks or months. Popular categories include animal products, processed foods, sugar, soda and caffeine.

One Meal A Day (OMAD)
As named, OMAD is a fasting method of eating just one nutrient-dense, high-calorie, high-volume meal a day. The recommended approach is to eat the meal within one hour and consume nothing except zero-calorie hydration for the following 23 hours. People typically approach this by fasting breakfast to breakfast, lunch to lunch or dinner to dinner.

If you’re considering fasting, talk to your primary care doctor first. Fasting isn’t for everyone. Depending on your age, gender, health conditions you’re managing and medications you’re taking, there are pros and cons to consider before you embark on depriving yourself of complete recommended daily calories.

If you get the green light to fast, make sure you’re hydrating. Foods contain water and make up some of our hydration. Fasting can leave you dehydrated. Drink lots of water.

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