I have a quick question for fasting gurus.
having watched/read Dr. Fung, specifically regarding how calorie restriction lowers metabolism, I am wondering this works for people doing OMAD?
I have been playing with it again for a couple of weeks, and I really seem to tolerate it quite well. However I am concerned that I may be damaging my metabolism as I am certain I do not eat more than 1500kcals during my dinner, and often less.
Is there some special sauce here to prevent the same slowdown that CR people see? OMAD would appear, at least on the surface, to be different than conventional 24/36/48 hour fasting as you are eating every day.
I (used) to do a lot of fasting, whether it was skipping breakfast, TMAD, OMAD, multi day water fasts, you name it. I ABSOLUTELY screwed up my metabolism bad! Physical job, Heavy lifting 4-5x /week, cardio 2-3x /week, and at 5’9" averaging 210-220lbs with ~180 of it being muscle I SHOULD have had an inferno as a metabolism… RMR testing showed I was at 1700! Not even the “normal” 2000 cals that we’re supposed to eat. Problem with OMAD is eating a days worth of food in your window. A combination of the fasting and me buying into the “Eat to satiety” thing is what destroyed me. I don’t know which one did more damage to me. What I know is I used to be able to loose weight eating 2500-2800 cals a day and being reduced to 1700 is literal HELL! Still fixing it now!
If you are familiar with Dr Fung, you probably also heard of his associate Megan Ramos who is his Nutrition and Fasting expert. ( Twitter description) . They do not recommend OMAD at all as a weight loss method, and in fact deny that it is even fasting, just a calorie restriction method. They believe that within 3 months or sooner the body slows down to meet the caloric needs that you are giving it. I enjoy OMAD and it works for me, but I change it up on weekends where I might fit in 3 meals or at least 2. Usually I’m Monday to Thursday OMAD, but even then sometimes I will mix it up throwing a breakfast in there once in a while.
They do recommend a fasting method that is similar to OMAD, which would be one meal for the first day, then lunch the next day , then dinner the next day, so that you are doing a 16/30 alternative day intermittent fast. That doesn’t work so well for me, so I’m good with what i do but I mix my quantify of food often so that calories will range quite a bit, day to day. On Keto it was around 1500-2000 per day, once a day, on carnivore it’s just under 2500 a day and up to about 3000 some days. You have to mix it up for OMAD to work. Here is a little article put out by Megan that will help answer your question
I can’t imagine it would matter if you do OMAD or not, undereating is still bad. What it means for who, I don’t know that. I need 1500+ kcal, that’s sure and sometimes more.
I never worried about my metabolism as I can’t eat little. I was fine with shockingly little food on OMAD for a few days - then my body noticed and I fell off the wagon due to huge hunger… Little food never worked for me, no matter what. Even if I felt great for days, it ended unwell. And it sounds logical to me especially with my not huge amount of excess fat. I can’t get enough energy from that, I need proper meals too. I’ve heard about huge people being fine with 1500 kcal for months, losing at a great pace… Surely their bodyfat helped them enough. And there must be some individual factor too.
Many of us, intentionally or “accidentally” have a higher calorie day when us can’t get enough energy on our current woe (I have that even when I eat on maintenance level). It surely does good for metabolism, often the moral too So if OMAD doesn’t give enough calories, a day or two per week with a bigger window may be the solution for some. I don’t have fixed rules, what happens, happens, sometimes I eat once, sometimes two or three times, whatever I need to get what I need… My typical meal became way smaller on carnivore(-ish) so I don’t often do OMAD on that diet. It seemed a way better idea on my previous keto when I couldn’t eat small meals at all and 2 of them was too much. Sometimes I did OMAD with extra bites around it… My fasting window still was pretty big.
I think we need to be flexible and figure out what works best.