Intermittent Fasting and Human Metabolic Health. Patterson RE, Laughlin GA, Sears DD, LaCroix AZ, Marinac C, Gallo LC, Hartman SJ, Natarajan L, Senger CM, Martínez ME, Villaseñor A. Journal of the Academy of Nutrition and Dietetics. 2015 Apr 6.
I usually read several papers a day and try to find time to blog on one of them and today this one won. My last blog was a mouse study on intermittent fasting types that found it had some benefits over calorie restriction diets, and the benefits of calorie restriction diets appear considerable. This paper was specifically looking at human data so I wanted to give it a read. One benefit of intermittent fasting that I like is you don’t have to count calories, or prepare a number of small sensible meals, which in a million years I’m never going to do.
The gist of the article is that the various forms of intermittent fasting seem to be at least equally effective as calorie restriction diets and they broke intermittent fasting into several types so they could better compare apples to apples.
- Complete Alternate Day Fasting: Participants ate every other day, ad libitum (as much as they wanted) on food days and on fasting days they ate nothing. They drank on fasting days, but nothing that contained calories.
- Modified Fasting: Participants ate what they wanted on food days and did energy restriction, generally 20-25% of normal, with liquid diet. Also these diets often weren’t every other day but were 5 days of food and 2 (non-consecutive days) of relative fasting. It’s the basis of the better known 5:2 diet.
- Time Restricted Feeding: Participants could eat ad libitum but only during certain hours of the day. It’s the method I thought I was doing with the Warrior diet, but it turns out what I’m doing is more in line with the Fast 5 (5 hour eating window starting at 5 pm, followed by 19 hour fasting in a 24 hour period), which is simpler. Best of all the the Fast 5 diet book is free.
As I’m reading more about the various fasting literature and the above 3 pretty much cover it. Some peoples recommendation being a combination or tweak of the above ideas. The Warrior diet being an example, sort of a modified time restriction diet as they allow light snacking during the fast period. The conclusion of this review was that all the methods appear to be effective for a variety of biomarkers described in the calorie restriction diets. As of yet there is not enough data to strongly suggest that one intermittent fasting method is better than others, particularly in humans. However, in general they reported the human study findings were in line with the animal research. They note that unlike the animals, people sometimes cheat on their diets and complain. Noting that on the complete alternate fasting that…
“self reported hunger on fasting was considerable and did not decrease over time, suggesting that alternate-day fasting may not be a feasible public health intervention.”
…which changes my plans a bit. I was planning the alternate day fast for 30 days, after 30 days on the Fast 5. However it sounds like in reality, alternate day eating is just as miserable as it sounds and you don’t get used to it. So maybe I’ll just try it for a couple days, just to say I did. On the contrary, I’m 17 days into the Fast 5, and so far it’s a cake walk, figuratively if not literally.
Thanks for reading my blog. If you have any questions or comments (even hostile ones) please don’t hesitate to ask/share. If you’re reading one of my older blogs, perhaps unrelated to neck or back pain, and it helps you, please remember Spinal Flow Yoga for you or someone you know in the future.
Chad Reilly is a Physical Therapist, obtaining his Master’s in Physical Therapy from Northern Arizona University. He graduated Summa Cum Laude with a B.S. Exercise Science also from NAU. He is a Certified Strength and Conditioning Specialist, and holds a USA Weightlifting Club Coach Certification as well as a NASM Personal Training Certificate. Chad completed his Yoga Teacher Training at Sampoorna Yoga in Goa, India.
2 thoughts on “Intermittent Fasting Types and Terminology”
Hi Chad. Listened to your recent interview with Steve Anderson and had some questions as to how you are doing your eating window. Do you eat one giant meal? Do you just graze for 5 hours? Do you eat a meal at the beginning and end of the window? Just wondering how you approach the window and if it has changed the further down the IF path you have gotten. Thanks!
Now I usually eat one big meal and call it good. When I first started fasting, about 4 years ago, I was more into “windows” and trying to get enough protein in, that I wouldn’t lose muscle, trying to get a gram of protein per pound of bodyweight as many bodybuilders try and do. So if I had a 4 hour window, I would hit a protein shake to start, usually at 5 or 6 pm, then eat my dinner that could be whatever, and then drink another protein shake right before my window closed at 9 or 10 pm. However, I think I was getting too much protein back then, at least too much in such a short time, so I’ve reduced that to ONE shake, and I’ll drink it either before or after my meal, usually within a few minutes, and almost always within an hour. Between eating a single meal, vs a short window of 2-5 hours I don’t think it makes a lot of difference, but I think shorter is better if you are trying to lose fat, as you’ll feel more full relative to however much you eat. It is something that gets easier with time, I never really decided I was going to eat one meal, it more or less turned out that way when I started counting and reducing my calories, to see how lean I could get and to optimize my strength to weight ratio to test higher on the SF5 exercises. It does seem that so long as I’m increasing my reps on SF5, then I wasn’t losing muscle. In contrast when I was doing some longer fasts of 2-5 days, I did lose muscle, even though I was lifting weights regularly at the time.