Intermittent fasting (IF) is an eating pattern that cycles between periods of fasting and eating. It does not specify which foods you should eat but rather when you should eat them. In this respect, it is not a diet in the conventional sense but more accurately described as an eating pattern.
Popular Intermittent Fasting Methods
- Eat-Stop-Eat: This involves fasting for 24 hours once or twice a week. For example, not eating from dinner one day until dinner the next day.
- The 16/8 Method: Also called the Leangains protocol, this involves skipping breakfast and restricting your daily eating period to 8 hours, such as 1 PM to 9 PM. Then you fast for 16 hours in between.
- The 5:2 Diet: With this method, you consume only 500 to 600 calories on two non-consecutive days of the week but eat normally the other 5 days.
How Intermittent Fasting Affects Your Body
When you fast, several things happen in your body on the cellular and molecular level. Here are some changes that occur during fasting:
- Human Growth Hormone (HGH): The levels of growth hormone skyrocket, increasing as much as 5-fold. This has benefits for fat loss and muscle gain.
- Insulin: Insulin sensitivity improves and levels of insulin drop dramatically. Lower insulin levels make stored body fat more accessible for energy.
- Cellular repair: When fasted, your cells initiate cellular repair processes. This includes autophagy, where cells digest and remove old and dysfunctional proteins that build up inside cells.
- Gene expression: There are changes in the function of genes related to longevity and protection against disease.
These changes in hormone levels, cell function, and gene expression are responsible for the health benefits of intermittent fasting.
By reducing your calorie intake, all of these methods should cause weight loss as long as you do not compensate by eating significantly more during the eating periods. Many people find the 16/8 method to be the simplest, most sustainable, and easiest to stick to. It is also the most popular.
As with any dietary change, it is important to consult with your healthcare provider before starting intermittent fasting, especially if you have any underlying health conditions.