PSMF with IF/OMAD (low calorie)?

(Bob M) #21

I have decided I can fast and not eat, but if I eat, I can’t eat a small amount. The idea of a PSMF is really about low calorie. And I haven’t been able to do low calorie.

What I’ve been doing is eating higher protein, lower fat, and trying for one 36 hour fast per week. I’m averaging 2 out of 3 weeks for 36 hour fasts, though sometimes that’s due to external events. For instance, today would be my normal fast, but I’m working from home and going to visit my mother. I’ll eat with the family tonight, and it’s tough to sit in front of the family while they eat but I don’t.

I think fasting can be tough, because I do think we can cause our metabolic rates to decrease. How long does that take? I don’t know.

But it also makes sense to me that a PSMF should do the same: at some point, your body will say “Hey, I’m starving here! I’m going to shutdown!”

I think PSMF - if you can do it - is a tool like any other tool. If you try it and it works, then it’s great. If you try it and it doesn’t (or like me, you can’t do it), then it’s not.

Another thing I have been doing is to try to eat a bit more before I hit a 36 hour fast. I THINK that might be helping, but I’m not sure. My guess is that rotating PSMF, longer fasts >24 hours, and the like, with eating a lot might trick our bodies to prevent them from lowers BMR (basal metabolic rate). But, of course, I have no real data on that.

Anyway, let me know if you try a PSMF and if so, if it works for you.

(Central Florida Bob ) #22

When I see something like 500 calories a day, I think that’s like 4 or 5 ounces of meat, especially if you put anything on it. It’s not even something particularly high fat. A 500 calorie PSMF day isn’t sparing much protein, just some.

I’m just finishing 40 hours of fast today, and after my 6 or 7 hour eating window today I start another fast. I find I’m not really hungry, I just want to eat. Eating is pleasurable - who’d have guessed?

(Bob M) #23

Yeah, it’s really tough to eat that few calories.

There are different viewpoints, and some believe protein helps with satiety. I do find this to be correct for me, at least to a point. That point? When I eat too few calories, I’ll still get hungry.

But in general higher protein for me equals satiety. Right now, I eat a lot of leaner meats, but I still don’t stop eating fat. For example, for “Taco Tuesday” (which is Wednesday this week), I’ll have sour cream. So, while I’m eating a lot of low fat meals, I’m not going crazy about not eating higher fat.

I also found when I was trying to eat a lot of saturated fat that if I ate a TON of saturated fat over a short period, I got a tremendous satiety signal. I did this at “lunch” (my first meal of the day).

The problem? Since it was a pandemic, my kids were home. So I ate dinner with them. And even though I was NOT hungry AT ALL, I would end up eating a normal meal. There’s something hormonal, I think, that causes me to want to eat.

(Doing a Mediterranean Keto) #24

I do PSMF (but relatively high fat, not low fat).

For me at least, IF does not work, I prefer to eat several times per day (4), smaller portions. But this is not in PSMF only, it is in general.


Sometimes it’s a tiresome chore to me… And fasting can be very pleasurable too :wink: But yeah, I am a big foodie hedonist, I can understand. Eating is a very important joy of life for me and I don’t want it to change ever. Some people consider eating mere refueling, it’s fine but I am not like that.

500 kilocalories is 150g pork chuck roast, it’s such a tiny food, I would get hungry eating that! PSMF is like low-fat, belongs to my room 101. I am a lot like Bob, I need proper sized meals.

And eating a really substantial meal before EF definitely helps me - though I still have a hard time to do it, that’s why my last EF was ages ago. But without very well-fed just before it I have even smaller chances. The bigger my meal, the longer I fast, typically. Tiny meals makes me hungry right away. 1200-1500 kcal lasts for 3 hours, usually (carbs raises the numbers, it’s for very low-carb)… Bigger ones typically last for a day. But food choices matter too, not surprisingly.

For satiation, I need lots of protein and lots of fat (the higher the carbs, the more, no wonder I prefer staying close to carnivore). Just lots of protein can’t work though I probably will make more experiments. But I just stop eating protein at some point and miss the calories, it’s quite bad, according to my tiny experiments. It takes a different type of person to do that and be okay with it (= not eating up a lot of super fatty protein extra to get rid of the bad feeling).

(Doing a Mediterranean Keto) #26

I guess different people are different, but I would not say 150g of pork is little.

It is not a lot, but not little.

Myself, I eat 150g of meat/fish/… per meal, so it is reasonable to me.

Just to understand: how many eggs do you use for an omelette?

(Michael - When reality fails to meet expectations, the problem is not reality.) #27

Just curious, when I think about PSMF. How is this ‘fasting’? I get the ‘protein sparing’ bit (although at the risk of protein poisoning), but eating 500+ calories of protein is not fasting. It’s just restricting calories from both carbs and fat. ‘Modified fast’ would be something like do you want to drink plain water, salted water or club soda.

(Doing a Mediterranean Keto) #28

Yes, that is a good point, a PSMF is not fasting. I guess there is an analogy with Longo’s Fast Mimicking Diet.

The idea is that if you are at say 20%, you are closer to 0% than to 100%.

(Michael - When reality fails to meet expectations, the problem is not reality.) #29

:innocent: Fasting is like pregnancy. You are or you aren’t.

I think the folks who came up with the idea just didn’t want to call it the ‘Rabbit Starvation’ diet.

(Doing a Mediterranean Keto) #30

It depends. There is dry fasting, there is fasting with water, and with coffee or tea …

But yes, I would never say that what I am doing is “fasting”.

(Old Baconian) #31

Ah. I’ve always thought that “protein-sparing” referred to sparing the protein already in the body


2-3 eggs for an omelette/scrambled eggs but it’s just the first eggy course of a proper meal in my world. 8 eggs is a decent amount of eggs per meal/day for me but it’s very little food, no way I get satiated with it under normal circumstances so I eat other things. It’s not too many eggs to have along with a proper amount of meat for a proper, substancial meal (like, 500-600g pork chuck, my most important staple meat).
I never was good with tiny meals but occasionally they happen, just usually very close to other meals.

But super rarely I have 60g meat days too, it’s not a meat dish, just some processed stuff or a turkey neck in my soup. But those almost never are carnivore(-ish) days as I can’t live on eggs and dairy.

It’s different for you and many others as you function well with more than 1(-2) meals a day and you eat a significant amount of plants even on a good day.
But I like the meat I eat anyway and a little would be so pointless, I mean business when I eat, I couldn’t get satiated with a little (unless I would eat very many eggs in various forms including desserts but it’s better to eat more meat).

I see 500g pork a really not big piece after I roast it… Nice, not too little (except when it is) as it’s only the main course, not the whole meal but it’s so small on my plate… :smiley:
But I have my own idea about what is small or too little food.

Indeed but there are these things called fasting. Egg fast, fat fast, PSMF. They aren’t fasts but one eats in a restrictive way and I don’t know why but people call that fast sometimes… Egg fast doesn’t even have a calorie restriction, technically, one eats fat and protein alike though very little protein unless someone is able to eat much on that horrible, insanely fatty mini-diet (I can’t but I quit after 9 hours anyway when I tried. but it was very satiating while lasted, similarly to the fat fast that I quit on the 2nd day and only because I got paranoid about my protein).
The egg fast has the worst name as it has very little eggs and it isn’t a fast AT ALL, I think it’s recommended to eat many times a day…? I couldn’t eat much at once anyway unlike on the fat fast (if 1000 kcal is much for someone, that was the amount there and it was enough for a day for me, amazing).

I feel compelled to try PSMF for a day once (scratched that, make it low-fat, so <80g. that’s little, right?). It can’t be much worse than the egg fast… And in the worst case I will get interesting experiences and then quit soon but TRY a meal. It just needs an insane focus to avoid fat. I am bad at it. Once I wanted to eat lots of protein and only focused on my protein and ended up with 220g fat somehow. Once, very long ago I just jumped one of my no satiation fav foods, bread with honey, ate a ton of it and ended up with 45% fat somehow. Fat just appears around me. I need my decade long training and habit and a low level continuous focus on keeping it as low as I comfortably can to only go over 200g fat occasionally. 280g regularly happens but I am usually way lower. But going below 80g… Sounds impossible. But I will make some honest attempt one day :slight_smile: (Without eating a ton of sugar the previous day as that would make it almost realistic… I had 500kcal days in my life. Not every year, even full fast days are more frequent but they happened.)

(Central Florida Bob ) #33

I was going by the way people talk about egg fasts or things like that, where they eat nothing but eggs. I think I remember someone talking about a bacon fast. I thought protein sparing fast meant eating nothing but protein.

As I said up above, I know next to nothing about PSMFs. I watched an hour long documentary on Amazon Prime about fasting that specifically talked with Valter Longo about PSMFs but that’s long enough ago that nothing much deeper than remembering I saw it survived.

(Doing a Mediterranean Keto) #34

Question: this amount of food refers to OMAD, right? Or do you eat all this amount more than once per day?

(Michael - When reality fails to meet expectations, the problem is not reality.) #35

Didn’t know where else to put this. So put it here, as somewhat related to topic. I think it’s a very interesting paper.



The ‘protein sparing’ effect of the KD is well noted in the literature. However, I believe this is challenged when energy restriction is one of the variables. I posted this elsewhere:

Nutrients | Free Full-Text | Effects of Combining a Ketogenic Diet with Resistance Training on Body Composition, Strength, and Mechanical Power in Trained Individuals: A Narrative Review (


Sorry for the late answer.

It’s for my first meal, usually. It doesn’t matter if I have OMAD or I have more meals. My first meal is typically proportially huge, it’s what comes naturally. After a 18-23 hour fast I need my calories and protein and fat, I can’t help it. I may get away with a small meal, like 1000-1200 kcal occasionally but I tend to get quite hungry very soon then (1 hour is typical for small meals).

I had some low-fat protein and tried to make a PSMF meal and see if I last for 1-2 hours… Nope. It was 1000 kcal and 50% protein (tiny and unusually protein rich in my world) but I just couldn’t stop, had to add a lot of fat too, it was automatic, I couldn’t even stop and wonder, I was hungry, I had to continue to eat.
So yeah, PSMF seems to be impossible for me even for a meal. No matter how curious I am, I just can’t do it.