Being a sort of health nut, I dabbled in eating only one meal a day a few years ago. I first heard about the “Warrior Diet”, which is listening to your instincts when it comes to eating food. Ancient warriors would hunt and gather during the day, and would eat their catches at night. Apparently, eating 3 meals a day came from European settlers who decided that we needed to be more civilized and sit down for meals instead of eating whenever we felt the need to.
The idea is that you eat all of your daily calories in one meal after fasting for 8+ hours. While fasting, your body will start to use stored fat for energy. You will burn fat, improve cognitive health, improve glucose metabolism, and can even lengthen your life span.
The downfalls of doing the one meal a day diet were mainly the judgmental comments and looks I would get from my coworkers when they noticed me skipping meals. They definitely thought that I had an eating disorder and would persuade me to eat when I was trying to fast, which drove me to be insanely annoyed with them. Another downfall was that after eating a big meal after fasting all day, I would get extremely tired when digesting my food and had no energy to go out. It was a hard thing for me to do on the weekends.
On the other hand, I felt great. I did it for about 3 months and was in the best shape of my life. I surprisingly had energy during the day even though I wasn’t eating. I haven’t done the one meal a day diet for a while now, mainly because I switched jobs and now I stand all day so fasting can make me feel a bit faint, but I would like to go back to doing it. The “Longevity & Why I Now Eat One Meal a Day” video (linked above) has some of the best, most persuasive information I’ve seen on the topic.
“Our ancestors consumed food much less frequently and often had to subsist on one large meal per day, and thus from an evolutionary perspective, human beings were adapted to intermittent feeding rather than to grazing.”
(Mattson, M.P., PhD, Lancet 2005; 365:1978-80)
There is also a blog post which contains the same information as the video found here.