PSMF and Fat Supplemented Fast Experiment

(Shawn Cochran) #1

So I didn’t get much in the way of a response on showing me the science between a Protein Sparing Modified Fast or with a Fat supplemented fast. I did some reading out on the internet on both including @richard 's post on how people that are somewhat lean (15-20% BF) would probably need to supplement with fat to get through an extended fast. Since I am at about 20% BF and did a 3 day fast that was fairly difficult for me to get through, I’ve decided to try both ways.

So I’ll do a 5 day PSMF(about 0.8 g protein/lb lbm with minimal fat & carbs) as per Lyle McDonald I’ll take a week off and do some maintenance (or maybe just 2 days of keto feasting) and then do a 5 day Fat supplemented fast (I think about 40 g fat, 0 protein, 0 carbs) and report the results.

I’m working on the specific protein or fat amounts per Lyle McDonald and Richard’s calculator (compared to my own spreadsheet for fat burning calculations). I’ll post my results when I’m done. 5 days may or may not be long enough to show a difference, but I’ll also check blood glucose levels every day. I do question the need to do so since glucometers can vary +/- 20 mg/dl but at least it will give me a ball park idea of where BG levels are sitting. Just for the record, I have not been diagnosed with diabetes and have no other health issues.

(Richard Morris) #2

I believe a gluccometer model has to be within 20% of the lab results to be certified for sale in the USA and Australia, but most have tighter tolerances. But I think an individual meter is very reliable for point to point comparisons. So if your meter said your BG was 100 then it could be from 80 to 120, but if you tested again in an hour and it showed 90 then you can be pretty sure your glucose had moved 10% lower.

One trick for reducing inaccuracies caused by the collection method picking up glucose on the skin, is to express a larger droplet of blood and put the collection surface of the strip in the middle of the droplet where there will be less contact with the skin surface.

I’m interested in your experiment but I suspect you won’t see as much difference as the purpose of supplementing with fat to support fasting is to add energy to make up for the fact that body fat is capping out. Protein is also energy but not as dense as fat. At 40g of fat you are proving 360 kCal/day of energy. That’s roughly the same energy as eating 90g of protein (not sure what your lean mass is so don’t know the exact amount you’ll be eating).

I suspect the biggest difference will be internal where the fat supplemented fast should provoke a maximum rate of autophagy after 3 days. The protein supplemented one probably wouldn’t.

(Shawn Cochran) #3

Thanks for the response @richard. I don’t expect to see a big difference between the two either except in how I might feel. I work in a 10 hr a day job and am constantly walking and moving so pretty physical. Energy levels are key for me. On normal keto diet, no problem, during the fast it was rough. I am a 46 yr old male, 6’ tall and about 194 lbs (down from 234) and about 20% bf based on visual. Would love to get a dexa scan but not in the budget right now. My goal is to drop down to 15% BF if I can. Working out body weight resistance training 2x a week, walking stretching and some yoga the rest of the week plus work.

As someone with a biochem background, the accuracy of the glucometer bugs me a bit. I’m used to instruments I can calibrate and are very accurate. I get that the glucometers are accurate up to a degree. I take precautions to minimize variables in my samples (ie. washing hands with hot water, not squeezing etc). In your example above, I understand but I have taken four samples in a row one morning and have gone from 88 to 108, so when I pull my one sample a day (say for example 93 on day 1) and then my sample on day 2 goes up to 103, how I can I honestly accept that number when in reality that number could be 83? I’m more or less just taking it as a good number or a bad number. I have yet to get a number above 108 so I’m feeling pretty good about my numbers. I did have a blood test about 6 months ago though and my fasting BG was 85. Sorry, didn’t want to ramble on about his as I have read the discussion on accuracy as well.

Overall the goal of this experiment is to see how much weight I drop using each modified fast and to see how I feel during each fast energy wise. Cheers!

The Ketogenic Brewer :beer:

(Richard Morris) #4

I’m also very interested in how you brew ketogenic beer :slight_smile:

(Shawn Cochran) #5

Lol yeah still working on that. I work as a brewer but found keto in the past year. A bit challenging. I did make a homebrewed 3% abv pale ale with 10 g carbs per 12 oz serving. So I might have 1 on a weekend night but I don’t think it will get much better than that. A friend of mine is going to make a cider and backsweeten with xylitol. As all the sugar of a cider is consumed during fermentation this might work.


5 days isn’t long enough for Lyle’s PSMF so I don’t know if that will tell you much.

(Shawn Cochran) #7

It’s more to get an idea of how my body feels while on a modified fast. The 3-day water fast I did was pretty difficult. Energy levels were crashing hard. So I’ll try supplementing with protein and then supplement with fat and see what happens.

(Scott Telfer) #8

I find this aspect fascinating. I’m 16/17% body fat and I find 2-4 spoons of mct/coconut oil really let me ‘fast’ for longer periods

(Shawn Cochran) #9

Well, day 2 down on the PSMF. So far so good. Not feeling like I was completely drained. Still getting a little tired at the end of the day, but I kind of expected that.

Day 1: So basically doing IF while on this so I ate about 9:30-10:00 am and then again about 2:00 pm, nothing after that. Was a bit foggy mentally, but not too bad. Felt hungry at times but felt satisfied after both meals for quite a while. Took my BG at 9:00 pm right before hitting the sack as I am working early shifts this week and so was up at 4:00 am. BG on the handy ol’ glucometer was 91 mg/dl.

Day 2: Up at 4, had my coffee black (I really miss my cream and coconut oil), grabbed my food and out the door about 4:30 and off to work. Hungry, but not feeling like I was starving. Ate my breakfast again about 9:00 and then lunch about 12:30-1:00. Energy level was good. Fogginess wasn’t there. Did my body weight resistance training today after work and took the dogs for a walk. Will check my BG before I hit the sack.

Here’s a question that I’ve always wanted answered: Since protein is somewhat insulinogenic, if you do IF, you are basically taking in a larger amount of protein in 1-2 meals, shouldn’t that by definition kick you out of ketosis? So in that case, you’d only be back in ketosis after about 4 hours or so after your last meal. So if you do a 16/8, you are really only in ketosis for approximately the time the insulin drops off until the next morning (or whenever) so perhaps 12 hours. Just a thought.

One other thought: people have said I wouldn’t get the benefit of autophagy doing a PSMF, but I think I disagree with this. As I am basically doing IF, I should still receive the benefit of autophagy during the fasting hours. Just because I’m only eating protein with minimal fat and carbs, doesn’t automatically negate autophagy (when in the fast zone).

(Shawn Cochran) #10

Day 3: Pretty much same as yesterday. Good energy with some hunger here and there. Definitely starting to look forward to the weekend when I can eat fat again. Missing it in coffee, butter on my veggies, etc. However, I started at 196 lbs on Mon and weighed in at 192 today. Pretty decent drop for 3 days. BG last night was 95 last night so in the same area numbers wise as the night before. Pants are a bit looser and I had to tighten the belt a little bit more so. When we took the dogs for a long walk tonight, I could tell I was generating some pretty good heat. Not fever heat, but in general I felt like I was exuding heat. No work tomorrow so I don’t have to be up at 4 so I’ll see how getting some more sleep impacts my energy levels. Got some yard work tomorrow so I won’t be sitting on my butt too much.

BG last night was 88 mg/dl and weight this morning was 191.5 lbs.

(Shawn Cochran) #11

Okay Day 4 and final day 5

Day 4: BG was 88 so lowest so far, but I suspect that my meter is reading about 10 points higher than what it actually is. Reason for this is my wife and I are trying to get the CAC scan, but have to have a “consult” with our doctor to get a referral. So while she was at her doc’s she got a blood panel done and her bg levels (even after 3 hours of eating) were at 75. I tested her at home later and it read about 88. Funny thing in her blood work though, her LDL levels were elevated. Which is what I would expect after listening to the podcasts from the 2 keto dudes regarding hacking cholesterol. Also reading Cholesterol Clarity right now, very interesting.

Day 5: BG was 95. Again I think this meter reads high. I can honestly say, I am really looking forward to eating fat tomorrow. Going to do a feast day or two and then hit maintenance for the rest of the week. The coffee with cream and coconut oil is going to taste so good. I also add a teaspoon of the hershey’s special dark cocoa powder. Yum yum. I was pretty tired today as well. I don’t ever get headaches but have a very slight one as I head to bed. Body is definitely missing fat. How can people think that eating fat is bad for you when it obviously tastes so good and your body craves it when you don’t get it. I guess I understand: this is the first time I can recall ever having a noticeable craving for fat and not carbs! Of course, beer (good beer, not the fizzy yellow stuff) tastes really good to me too.

I did test ketones this week using the ketosticks. I never went above small (light pink). When I did the 3 day fast, I was always at moderate or higher so spilling out acetoacetate.

A little side note: Lyle McDonald does say that in the middle of the week you should have 1 meal where you eat unrestricted and then 1 day at the end of the week to do the same. I did 5 days straight though as I was already fat adapted and figured my body could handle it. Seriously though, I don’t know if I could have done this being a glyco-burner. I’ll also disagree with Lyle that having a meal mid-week and a day at the end of the week to eat unrestricted would be beneficial for a glyco-burner. In my eyes it would continually make things more challenging by jumping in and out of ketosis without ever getting fat adapted.

Added this morning: my final weight was 190.5 lbs, down from 196, so 5.5 lbs lost in 5 days. Not too shabby.

The Ketogenic Brewer :beer:

(Steve Stephenson) #12

It’s hard for me to go beyond a 3 day water+salt fast. My last fast I went to day 4, but I felt weak and my wife (carb burner) was worried that I looked fragile (she worried about possible stroke – I’m 75).

@richard In addition to not affecting autophagy, will a fat supplemented fast (say with coconut oiled coffee) also not raise serum insulin levels? (I believe insulin stimulates growth of metastatic cancer sites.)

(Richard Morris) #13

Eating anything will stimulate some insulin. Thinking about food will stimulate insulin. Dietary glucose and 2 amino acids will specifically trigger a massive insulin secretion.

Dietary Fat is the caloric nutrient that causes the least amount of insulin secretion.

And yes Insulin and IGF-1 both drive cancer reproduction.