A few weeks ago, I wrote about the benefits of intermittent fasting for weight loss. In a MindBodyGreen podcast, Courtney Peterson, a nutrient scientist and associate professor at the Harvard T.H. Chan School of Public Health explains when to benefit most from the food you eat in the context of intermittent fasting. In short, our bodies respond in different ways to nutrients at different times of the day.
What is intermittent fasting? Alternate periods of eating and extended fasting for at least 14 hours is a form of intermittent fasting. It is also called time-restricted eating. You eat in a time-restricted window of 10 hours or less.
One intermittent fasting study looked at the consequences for rodents of grazing throughout the day versus eating for the day within an eight-hour window. In both cases, the rodents ate the same amount of food. The study found that rodents who did time-restricted eating had better blood sugar control and gained less weight. They had less fat in their liver and lower cholesterol levels. Across the board, these rodents were in better physical health.
Why would intermittent fasting have benefits independent of what you eat? A typical meal takes four to six hours to digest. Once you get to 14 hours of fasting you see the greatest benefits to the body. The body recycles “worn out proteins and cells.” It “rejuvenates and repairs them.” Fat burning happens to the maximum when people fast between 12 and 24 hours.
The longer fasting time allows your body additional time to eliminate sodium in your body and that lowers your blood pressure. The data show that happens when you fast for two to three days. Peterson does not say whether it also happens in a 14-hour period. But, she does believe that the benefits of intermittent fasting are greatest in the shortest eating window.
Peterson explains that when you come out of a fast, you are better able to build muscle. Eating more in a shorter period also has been found to reduce people’s blood-sugar level. How? You don’t need to secrete as much insulin to control your blood sugar level.
What time of day should you practice intermittent fasting? Peterson advises to eat breakfast like a king, lunch like a prince and dinner like a pauper. If you do, you are more likely to lose weight and to be less hungry. In a study comparing the two approaches, a group that ate dinner like a king, lunch like a prince and breakfast like a pauper struggled to lose weight and were hungrier. She believes it’s because your blood-sugar control is best in the morning and gets worse over the course of the day.
Here’s more from Just Care:
- Live longer, avoid ultraprocessed foods
- If you need nutrition counseling, Medicare may cover it in full
- How sweet is your diet?
- To live longer, you must both eat well and exercise
- Want to lose weight? Try intermittent fasting
