Question on OMAD, Metabolism, and Calories

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(George) #1

So I’ve been doing OMAD (dinner) for the past 3-4 weeks (not really including weekends) and have been doing pretty well at it. I’ve been consistently losing approx. 2 lbs. per week (which are pretty identical results to when I was having a light keto lunch plus a heavier keto dinner in the weeks prior to OMAD). After doing the math, my OMAD calories end up being anywhere between 600 and 900 calories per day, plus my protein and fat macros are pretty low from what I believe I should be intaking.

I did a 72 hour fast last week, which helped me understand the difference in feeling between hunger and just an empty stomach, so I can’t really call my recent mid-day stomach grumbling as hunger, and have no problem pushing through till dinner time.

My question is, is my daily low caloric intake going to harm me at some point? I have quite a bit of body fat at the moment, I’m 5’9, 253lbs.), but nowhere near as much as when I started keto a few months ago (297lbs.)

I’m really happy with what my progress has been so far, so I’m worried that I might negatively impact my metabolism with such little calories and hinder further weight loss.

Should I stop OMAD and have lunch and dinner within a 16/8 window again, or should I keep on doing what I’m doing with OMAD 5 days/week, with some extra meals on weekends?

(Karim Wassef) #2

If you’re fat adapted, OMAD cycles your metabolism. It doesn’t really change it on average.

Caloric restriction does hurt metabolism so you need to make sure you eat enough fat when you do eat.

Extended fasting will reduce metabolism but not as much as caloric restriction. It should also recover after the fast on refeeding.

(George) #3

Thanks for the info! I guess I’m having a tough time figuring out how to squeeze in enough fat during the OMAD. I usually use quite a bit of butter, olive or sesame oil, avocado, cheese, etc., but not sure how much more to add to get passed a calorie restricted threshold

#4

I don’t believe you need to worry about calories on OMAD, just protein. We keep forgetting that we have all the calories we need and we want our system to draw on that reserve.

#5

Sesame oil is a seed oil which almost all say is off limits.

(Karim Wassef) #6

You just don’t want to be running on 800 calories from diet. Keto allows the body to gently transition to fat burning. It does it hormonally but it creates a small but continuous deficit.

If you suddenly decrease your dietary energy intake too much, it pushes back and drops metabolism.

(George) #7

That’s another issue I guess I’m encountering. I’m usually able to eat anywhere from 5-8 oz of meat based protein on OMAD, along with keto sides, but I eat till satiated. I don’t know if I should push beyond satiation, or stop when full.

#8

The question was, will it harm and I believe it will not. Plus he’s already been doing this a while so it’s not “sudden”. And what of those that burn 4k calories on ultra marathons and other endurance feats of daring? Our ancestors did this all the time and I don’t mean prehistoric (theoretical) ancestors.

(Karim Wassef) #9

If you go too deeply into caloric restriction, there will me a metabolic drop.

Will it hurt? It depends. If you’re a fat burner, the ketone should step in and reduce the impact. If you’re a carb burner, it will absolutely hurt.

(Bunny) #10

I agree with this also, you want to try to get a feel for when your really really hungry. The goal is not to naturally not feel hungry even though your cutting back the carbohydrate part of the caloric restriction even with OMAD, if you are really really hungry don’t ignore it (be honest with yourself?) and eat something before that timing window or your leptin signaling will tell your body to hold on to the body fat. The more you spread out your eating windows the easier it becomes to not feel hungry in between a - 24 hour eating cycle.

If your fasting for therapeutic purposes (autophagy, diabetes etc.) other than burning body fat that’s another thing; you ignore that hungry feeling until the ghrelin wave spikes dissipate.

Just be aware and make a logical and clear distinction between those two things, because that subtle understanding makes a big difference depending on your goals and reasons for the methods you are choosing?

See also: 70% calories of dietary fat does not equal 70% volume

#11

How deep is too deep of a caloric restriction?

(Bunny) #12

I think it would depend on how much body fat you have compared to lean person that would determine how deep of a caloric restriction you would want to maintain?

A lean or muscular person is going to burn carbs immediately:

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(George) #13

Well I’m 253 now, and I believe the ideal weight for someone of my height would be at 180. Given I have that much body fat, I wasn’t really too worried about some caloric restriction, but I just wanted some opinions on what the best course of action would be (stick with OMAD, or incorporate lunch again into a 16/8 daily IF)

#14

Even if a lean person goes deficit enough to slow metabolism it is life extending and healthy. It’s one of the healthiest things we can do for long life. Now if your goal is to increase metabolism and life FASTER then that would be counter productive toward your purpose.

Generally speaking that is. Some may have medical conditions that contraindicate

#15

OMAD is a great maintenance strategy. If you want to continue losing it’s a good idea to mix things up now & again.

(Bunny) #16

With OMAD I would follow my hunger signaling and eat when I’m hungry and gradually space out my eating window until I did not feel hungry or ill (symptomatic; hypoglycemic: headaches, migraines, nauseous, weak, dizzy, brain fog, forgetful, tired or lethargic etc.)?

(George) #17

I guess that’s where my signaling might be off. Before keto, I’d get headaches/migraines pretty frequently, and could always eat. Since Keto, no headaches/migraines, and after I tried an EF, what I consider real hunger doesn’t start to peak until it’s close to my usual meal time.

I also exercise while fasted, right before meal time, and I haven’t lost any energy or ability to lift the same amount, if not more, than before.

(Karim Wassef) #18

My longest was was 19 days. I’m only eating on weekends now. I usually fast at least 3 days a week. I also OMAD when I do eat.

I measure my composition with DEXA and my metabolism with RMR before and after so I quantify my n=1.

I appreciate the longevity benefits of fasting.

However, I think we should decouple the metabolic impact of fasting from the epigenetic and hormonal signaling that is the underlying mechanism for longevity.

As with most things … there’s a sweet spot. Too high and oxidative stress gets you. Too low and your ability to burn fat diminishes and you easily gain weight even with restricted intake and inflammation gets you.

OMAD is great, as is fasting in general. But if you starve vs fast, then it takes time for the body’s metabolism to recover.

(Robert C) #19

This might be true but it is a bad situation if you have excess body fat you want to lose.
Slow metabolism means it is very difficult for you to lose more weight.

One of Keto’s good points is to keep calories high sometimes - keeping metabolism high but insulin low (because most calories are from fat).

Then skip some meals and drop some locally stored fat - go back to higher calorie intake periodically.

(Karim Wassef) #20

Nature likes waves… cycles… growth & decline… life and death…

When you fast and then eat, and repeat… you’re actually in sync. This is why OMAD is so natural.

The problem is when the average level of the waves drops too far… then your deficit triggers other responses that can be damaging.

If your RMR is 2000 and you go Keto. Without even noticing it, you’ll be satisfied around 1800. That 10% deficit, with the hormonal triggers of satiety and the availability of energy from your own body gradually pulls at your own fat. No stress… no pain… no hunger.

If your RMR is 2000 and you decide to go Keto and drop to 1000 while hungry… your body goes into metabolic revolt. This is not Keto.

For me, the natural response of going into Keto was satiation at about 10% less than my metabolism… it varies by person and few people are lucky enough to have their own RMR machine. I’m looking at you, Nick! @Don_Q