The study and the article refer to the 5:2 method whereby 2 days out of the week calories are restricted to a very low level and the other 5 days are normal eating days with no restrictions. That to me is not Intermittent Fasting. If you’re eating you’re not fasting.
Intermittent fasting, to me, is better described as not consuming any food for a large portion of your day. For instance, consuming one meal a day means you’re not eating for about 23 hours out of each day. It’s not calorie restricted. You eat what you want during that one meal. But you are not eating the rest of the time. It’s intermittent because in normal fasting you don’t eat for and entire day or several days or more.
I don’t even buy into the time restricted form of Intermittent Fasting where you can eat during an 8 hour window and fast for 16 hours. That’s just eating. If you eat breakfast at 8a, lunch at 12p, and dinner at 4p you’ve consumed a normal American diet. Especially if you’re eating a low fat high carbohydrate diet. No matter how you shift those hours that’s a lot of eating.
Fasting takes place between time-restricted feeding windows. The two main types of intermittent fasting include time-restricted eating and the 5:2 format.
During time-restricted eating, you can eat within an 8-hour window of choice. For example, it could be from 8 a.m. to 4 p.m. or from 12 p.m. to 8 p.m. During the remaining 16 hours of the day no food is consumed, only no-calorie beverages (like water and unsweetened tea).
The 5:2 format is when two non-consecutive days of the week are spent “fasting,” with only 25% of daily recommended calories eaten during those two days. If the average U.S. adult consumes 2,000 calories per day, that would mean 500 calories would be consumed on the two “fasting” days. The remaining five days of the week, you could eat your regular diet. This type of intermittent fasting is seen in “The Fast Diet” by Dr. Michael MosleyUS News & World Report