I don’t have any personal experience with intermittent fasting, but I have read research about the effects. I am a science educator and I’m a bit of a nerd when it comes to science, health, and nutrition. :)
Compressing one’s calories within a certain window of time really isn’t new. I’m 56 years old and for the most part, this is the way we ate in the 70s. You had breakfast, lunch, maybe a snack in the afternoon, and dinner. So that would be from about 7:00 AM to 5:00-7:00 PM.
When you know you’re not going to eat but a few times a day, snacks typically are not around. Out of sight, out of mind. I’ve read studies in which adults that ate meals and snacks were more likely to be obese. Other studies have divided the same number of calories on 8 separate occasions and in 3 meals. It was reported that those consuming the calories on 8 occasions had a greater appetite than those consuming the same number of calories in 3 meals.
There is a biological reason for this and it has to do with the hunger hormone, ghrelin. This hormone is highest before meals and lower after. Studies have shown the amount of ghrelin in blood samples was lower in subjects that ate 3 meals than those that ate more meals of identical foods. There is also evidence that the amount of ghrelin needed to suppress hunger differs in people. Hence, the reason eating small, frequent meals is effective for some.
Of course, intermittent fasting is coming on the heels of this trend of eating small, frequent meals to increase metabolism. Exercise and diet can influence metabolism. However, I haven’t read anything that definitively confirms this thought.
Frequent meals or meals within a few hours. In the end, it’s calories in and calories out and how your body responds.
P.S. I’ll be happy to cite sources if anyone is interested.