My PSMF Story

(Central Florida Bob ) #1

I’ve mentioned before around here that I’ve had to go on a PSMF fast for surgery (tomorrow). Today, on the last day of the preparation, I thought I’d post results. If anything unexpected happens I’ll add more tomorrow (if I have time) or later.

To begin with, although it’s obviously a PSMF, that’s not how the surgeon frames it. They call it a liquid diet, but it’s low calorie, low fat, protein shakes and zero calorie fluids only for seven days. Since I had to buy 8 days worth, at $11 and change per day, being a cheapskate, I’m doing 8 days. I bought Fairlife Core Power shakes because of the 42g of protein per bottle at 230 calories. Three a day is 690. I added a teaspoon of HWC to my coffee, getting me to 720 calories per day. Unfortunately, I didn’t shop carefully enough because they have 8grams of carb per bottle or 24g/day. On most days of regular life, though, I’m around 30g so it’s not really a big deal.

The results surprised me a bit. I lost a bit over 1 pound per day. According to my Renpho digital scale:

Date Weight lb.s BMI Body Fat % Lean Body Mass lb.s
01/18/23 212.8 28.8 28.0 153.2
01/19/23 210.8 28.5 27.5 152.8
01/20/23 209.8 28.4 27.3 152.4
01/21/23 208.0 28.2 27.0 151.8
01/22/23 207.0 28.0 26.8 151.6
01/23/23 206.0 27.9 26.6 151.2
01/24/23 205.2 27.8 26.4 151.0
01/25/23 204.2 27.7 26.2 150.8

(Left off all the other columns)

My weight at the end of an overnight fast the previous Friday (1/13) was 209. Why the big jump from Friday to Wednesday? I’m afraid that’s just going to remain a puzzle. I’ve gone to only weighing in once a week after about 36 hours of fasting because it’s more repeatable; I don’t know how that fits into this measurement. All I can say is they have in common being first thing in the morning, wearing the same minimal clothing.

As you might imagine, if I plot that piece of the spreadsheet, it’s almost a straight line.

While I like the progress, the experience was a bit of let down. As a way of living, it’s incredibly boring, and I’d consider it unsustainable long term. If it was repeatable, and I could stay on it another 15 or 20 days to reach a goal weight, I might be able to do it, but like anything with vastly restricted food choices there are just too many uncomfortable questions.

The first is how much comes back when we start eating again? If my scale says 205, like the last line, what is it “really?” Just having more in our digestive tract will add weight.

I think anyone who has been on a calorie-restricted diet, or even read about them (which is pretty much everyone here), knows that our bodies adapt and slow our metabolisms to reduce our CO in line with CI. (I like to pronounce CICO as “psycho”). It’s not just we need fewer because of the reduced weight, basal metabolism goes down.

That said, maybe it would be more interesting to experiment with PSMFs that use real food. If that varies from pure carnivore, which I almost am.


PSMF’s are great unless they make you ravenously hungry, like they do me… but they work!

Congrats on the fat dropped, luckily, BIA scales don’t know muscle mass from a brick, because you did NOT lose over 2lbs of muscle in a week, especially doing a PSMF, so no worries there!

Not much in a keto’rs case. Most of the rebound is reloading muscle glycogen, which somebody doing standard keto has little to none to begin with, the digestive waste comes into it, but that’s usually not much. I don’t notice any huge swings with going on/off PSMF’s, and I do mine with food.

(Central Florida Bob ) #3


I haven’t gone looking for info on PSMFs with food, yet. Is that essentially carnivore but reduced calories?

Maybe better, any links or recommendations on info? A good book?

(Bob M) #4

I think it’s just less food, although you could try leaner meat (think top round instead of ribeye). I also like ham, and even can like chicken breasts from good (local farm raised) chickens or brined, sous vided chickens.

The PSMFs usually are pretty small, 500 calories or so.

Hmm…no added fat to those shakes. Most people are taking them for the protein.

To lessen the chance of lowered metabolism, you could do a PSMF MWF or Tues/Thurs or something like that.

Maria Emmerich seems to like them, though she’s also lean anyway. But she has a lot of her clients doing them.

I have tried a PSMF, but I get too hungry. I’d rather fast 36 hours instead.


Not really, while there’s clearly different ways to go about it, the “official unofficial” way is typically considered the way it was laid out by Lyle McDonald in the Rapid Fat Loss Handbook, he’s the one that pretty much put them on the map when he was going on the Podcast tour about it.

Typically, it’s the low calorie, enough protein so you don’t lose lean mass based on your bodyweight, but also allows unlimited green veggies and a very limited amount of some others.

(Bacon is a many-splendoured thing) #6

It’s essentially a ketogenic diet, with no intentional limit on calories (eat to satiation, in other words).

(Central Florida Bob ) #7

I can’t argue with the 1 lb/day rate I had, it’s just that it was insanely boring. The shakes weren’t disgusting, but one flavor for a week is too restrictive.

Maybe they’re trying for a flavor zone between good enough to not say, “I’ll never buy one of these again” and so good you want to cheat and have more.

Something like you say there about

I’ve done alternate day fasts for a six months, two years in a row. They never got me to a weight I was comfortable with as my goal. We’re adaptive systems, so new tools that our bodies aren’t used to seem to make sense.

(Central Florida Bob ) #8

So just for completeness sake, on the final morning, the trend of 1 lb/day continued. Final weight 203.2.

I expect to be out of it for a couple of days. Be back when I can.


(buzz) #9

I’m praying for you, Bob. I hope to see you back soon!



(Bob M) #10

I agree with this. If PSMF works for you, then give it a try.

(Central Florida Bob ) #11

Just a short note that I’m back from the surgery and doing OK. Still a bit sore, still have a half dozen incisions healing and my digestive tract getting back to actually eating, so not “DONE” done, but it went remarkably well.

The next phase is adapting to it and “eating as physical therapy.”


Yay! I hope your recovering will be quick too!

(Bob M) #13

Great news!