In the past decade, Intermittent Fasting (IF) has grown increasingly popular amongst health enthusiasts, including famous personalities like Jennifer Lopez, Kourtney Kardashian, Hugh Jackman, Chris Hemsworth, and more. Unlike traditional fasting, it does not require you to starve yourself. Instead, it is a diet schedule that involves alternating cycles of voluntary abstinence from food and drinks. While some intermittent fasting plans don’t restrict the type of food you consume during the non-fasting period, they recommend making healthier food choices during the non-fasting window.
Types of Intermittent Fasting
From time-restricted fasting and alternate-day fasting to modified fasting, these are the different types of intermittent fasting:
- Time-restricted Fasting – The most common type of IF includes prolonged nighttime fasts, such as the 16:8 method where individuals fast for 16 hours overnight, leaving an 8-hour window in the day to eat normally.
- Alternate-day Fasting – As the name implies, this type of IF means individuals alternate between days of fasting and days of eating. This means that no food or drinks with calories are consumed on fasting days, only non-caloric drinks like water and sugar-free tea or coffee.
- Modified Fasting – This IF type involves consuming very little on fasting days. One popular method is the 5:2 diet, where individuals fast for two days a week and eat normal for the remaining five days.
Why and How Does IF Work?
Intermittent fasting alters the way your body obtains energy. Once your body goes into starvation mode and uses up its carbohydrate source for fuel, it will start using fat sources, which puts the body into ketosis, burning fat. According to an NIA-conducted review of IF-related research, published in the New England Journal of Medicine, ketogenesis, or the increase of ketones in the bloodstream, helps improve health and aging. Ketogenesis enhances the body’s defenses against oxidative and metabolic stress and activates the removal or repair of damaged molecules. The impact of ketogenesis also carries over into the non-fasting period and can improve glucose regulation, increase stress resistance and suppress inflammation. As a result, you will lose weight and reduce your risk of heart disease and diabetes. Repeated exposure to fasting periods can also result in improved mental health and physical performance.
IF provides a convenient way to eat fewer calories resulting in a number of physical and mental health benefits. It also realigns our eating patterns with our circadian rhythm (the day/night cycle) which helps regulate our metabolism and sleep, allowing us to get back in sync with our natural rhythms. While IF is generally considered safe and a great way to improve your overall health and lifestyle, it is always a good idea to discuss any new diet with your primary healthcare practitioner or doctor before starting.