Over the past few years, “intermittent fasting” has become a popular diet trend. Studies show it plays a potential role in weight loss, longevity, and chronic disease management. So what should you know before you try it and how can you make it work for you?
What is Intermittent Fasting?
This basically involves time-restricted eating. It’s not necessarily a calorie-restricted approach (which also has benefits for longevity and health) but simply requires you to eat your food within a certain window of time. For example, eating all of your daily meals between 9 a.m. and 5 p.m. (food window) and fasting (no food window) is one way to complete an intermittent fast.
The Benefits of Time-Restricted Eating
Fasting has many health benefits, including improved heart health, reduced cancer risk, gene repair, and increased longevity. Studies show it normalizes insulin sensitivity, boosts mitochondrial efficiency (energy in our cells), lowers fats in the blood, reduces oxidative stress, and promotes human growth hormone production. Keep in mind, Human Growth Hormone (HGH) helps to maintain, build, and repair healthy tissue in the brain and other organs. HGH also helps build muscle mass, boost metabolism, and burn fat.
According to a recent study, metabolic switching is another proposed benefit of intermittent fasting. This occurs when the body switches back and forth between using glucose for fuel and fatty acids (ketones). It’s known as metabolic flexibility (that’s a good thing). In addition, it promotes autophagy (awe tä fə-jē) which is the body’s way of clearing out damaged cells, to regenerate newer, healthier cells.
Different Ways to Practice Intermittent Fasting
There are different approaches to this type of fasting and a few “made-up” ways you’ll find all over the internet. But time-restricted feeding (TRF) and the 5:2 approach were the methods that were most effective according to studies.
The Overnight Fast
This is the easiest place for most people to start and is an example of time-restricted feeding. You basically finish dinner by 6 p.m. and avoid all food until 6 a.m. the next morning. These times are flexible but the idea is to fast for 12 hours overnight.
The 16:8 Fast
Currently, the 16:8 is the most popular intermittent fasting method and another example of TRF. You eat all of your meals in an 8-hour window and then fast for 16 hours. For example, if you eat between 9 a.m. and 5 p.m. (food window) and fast from 5 p.m. to 9 a.m. the next morning. The times are flexible.
- 7 a.m. to 3 p.m.
- 8 a.m. to 4 p.m.
- 9 a.m. to 5 p.m. (as mentioned above)
- 10 a.m. to 6 p.m.
- 11 a.m. to 7 p.m.
- 12 p.m. to 8 p.m.
Many people are currently using a 12:00 p.m. to 8:00 p.m. window. But skipping breakfast and eating later in the evening goes against our body’s natural circadian rhythm. The 12-8 eating window eliminates food (especially protein) when you need it most (mornings) and promotes eating too close to bedtime. If you are trying a 16:8 approach, it’s best to finish your last meal by 6:00 p.m. Some proponents of this type of TRF feel that a 14:10 approach is more realistic as it opens up the eating window to ten hours instead of eight.
The 5:2 Intermittent Fast
Three studies show that this approach is very effective for improving insulin sensitivity (blood sugar balance), weight loss, and reduced waist circumference. The 5:2 fast involves eating normally five days a week and eating only one meal two days a week (non-consecutive days). The one meal should be about 600 calories. Everything outside of this one meal-a-day approach includes fasting time. This method may be easier to implement as a 6:1 approach (six days of normal eating and one day eating only one meal ).
Give it a Try!
Keep in mind, that during the fasting times you are only allowed water or non-caffeinated herbal teas. While there are many other different types of fasting methods, such as extended fasts (beyond 48 hours), the ones described above were very effective and easier to maintain as part of a healthy lifestyle.
“The best of all medicines is resting and fasting.” – Benjamin Franklin
Thanks so much for this! The chart makes it easier for me to arrange my meal plans.
Thanks. I’m sharing this with a friend who skips breakfast! She’s fasts everyday 7pm-11am.