Intermittent fasting, also known as intermittent energy restriction, is an umbrella term for various meal timing schedules that cycle between voluntary fasting and non-fasting over a given period. Methods of intermittent fasting include alternate-day fasting, periodic fasting, and daily time-restricted feeding. There are many different types of intermittent fasting, such as the 16/8 or 5:2 methods. People who follow this eating plan will fast for 16 hours a day and consume all of their calories during the remaining 8 hours. T he 16/8 method involves fasting every day for 14–16 hours and restricting your daily eating window to 8–10 hours. Within the eating window, you can fit in two, three, or more meals.
Water, coffee, and other zero-calorie beverages are allowed during the fast, but no solid foods are permitted. Intermittent fasting can: Stabilize blood sugar levels, increase resistance to stress, and suppress inflammation. Decrease blood pressure and cholesterol levels, and improve resting heart rate. Improve brain health and memory. Some people believe that this method works by supporting the body’s circadian rhythm, which is its internal clock.
Most people who follow the 16:8 plan abstain from food at night and for part of the morning and evening. They tend to consume their daily calories during the middle of the day.
There are no restrictions on the types or amounts of food that a person can eat during the 8-hour window. This flexibility makes the plan relatively easy to follow.
Intermittent fasting enhances hormone function to facilitate weight loss.
Lower insulin levels, higher growth hormone levels and increased amounts of norepinephrine (noradrenaline) all increase the breakdown of body fat and facilitate its use for energy.
Intermittent fasting works on both sides of the calorie equation. It boosts your metabolic rate (increases calories out) and reduces the amount of food you eat (reduces calories in).
Fruits, vegetables, and whole grains are high in fiber, so they can help keep a person feeling full and satisfied. Healthful fats and proteins can also contribute to satiety.
Beverages can play a role in satiety for those following the 16:8 intermittent fasting diet. Drinking water regularly throughout the day can help reduce calorie intake because people often mistake thirst for hunger.
The 16:8 diet plan permits the consumption of calorie-free drinks such as water and unsweetened tea and coffee during the 16-hour fasting window. It is important to consume fluids regularly to avoid dehydration.
Every action has an equal and opposite reaction, intermittent fasting too comes with its own set of advantages and disadvantages. 16:8 intermittent fasting has some associated risks and side effects. As a result, the plan is not right for everyone.
Potential side effects and risks include:
- hunger, weakness, and tiredness in the beginning stages of the plan
- overeating or eating unhealthful foods during the 8-hour eating window due to excessive hunger
- heartburn or reflux as a result of overeating
