30 and change Calories per lb of excess fat


(Jeffry Lauder) #1

Is this a hard and fast rule? I’ve heard @richard mention that we can only use a seemingly very prescribed amount of body fat for energy during a given day. I guess I have some confusion around this information because my inclination is to assume that number is related to insulin sensitivity and fat adaption. Is this just a hard coded upper limit that our body enforces some how? I’d love to know more about this. Thanks!


Is weight loss ever too rapid?
(Richard Morris) #2

That limit (290 kJ/kg (body fat)/day or roughly 31.5 kCal/lb (body fat)/day is given by this study

blog.2keto.com/alpert-2005/

It works out to be a transaction limit of about 1% of your total account per day.

But you can also draw less energy from storage than that. If for example you don’t need that much in a day … obviously you will use less. Also there can be structural reasons that you can’t access some body fat, for example if the tissue grew faster than it’s blood supply (in which case it’s probably hypoxic and very sick).

Finally one of insulin’s primary roles is to push circulating energy into storage when insulin is high, and release it from storage when insulin is low. So if you can’t get your insulin to go low when you need energy (ie: type 2 diabetic) then that will be a further restriction on how much energy from storage you have access to.

The underlying data from that Alpert study was from Ancel Keye’s starvation studies after WWII. Unfortunately Seymore S Alpert died in 2014 so we can’t ask him if there is other starvation data that supports or challenges his numbers … but I am on the look out for starvation studies that could do just that.


(Jeffry Lauder) #3

Ooh wow, that’s really interesting. So there’s a weight loss speed limit enforced by your body during fasting. I wonder if there are ways to measure that limit while feasting, it would be interesting to see if it changed then, or perhaps was higher during the earlier portions of a fast.

I saw that the abstract also mentioned a similar (but slightly lower) relation to resting metobolic rate and body fat during fasting. I wonder if these continue to be correlated as you start consuming fuel again. Thank you so much for taking the time to respond.

Edit: now that I think about it I suppose insulin would be a limiting factor while feasting or during the early part of fasting.


(Richard Morris) #4

Yes you can draw down roughly 1% of your body fat a day, and it will be less if your insulin is high. But body fat isn’t the only component of weight loss. If the amount you can get from body fat isn’t enough energy to adequately fuel your body, then you will draw the arrears from burning amino acids that you draw from lean mass.

So the context of how much energy you need, and how much that can come from body fat will dictate how your body composition will change.

The theory advanced by the energy balance consortium (ie: Coca Cola funded scientists, dietitians, and personal trainers) that if you have 10 lbs of body fat you must have (10 lbs x 3500 kCal/lb =) 35,000 kCals of available energy is not borne out by the mechanism, or the evidence. You really only have 315 kCal while fasting and if you need 1200 for your day then you will need an additional 885 kCal and you will find around 221g of protein to burn to get that.


(Dustin Cade) #5

how does autophagy play into this? Do we know how much is being processed during the process of autophagy?


(Richard Morris) #6

Protein is a massive structure folding in upon itself and it gets most of it’s function from it’s shape not it’s chemistry. Sometimes proteins become misfolded and cells quarantine them in reservoirs and then when the cell gets a break in normal frenetic activity … it recycles that protein. That’s what autophagy is, a normal process that happens in cells when they have some downtime. Fasting drives a hormonal signal that tells your cells it’s down time so start breaking down junk proteins into it’s component amino-acids into what is called your labile store of amino acids, ready for the next feast where they will be built up into new fresh proteins.

No fat is processed in autophagy. But if you don’t have enough body fat to adequately fuel your body then you will tap that labile store first burning amino acids for energy. That labile store is about 1% of your total protein, so once that is tapped you’ll be cannibalizing any protein structures optional to immediate survival - like muscles.


(James storie) #7

Dang @richard, I was just about to say the same thing! Hahaha! :laughing:


(Richard Morris) #8

You can get the next one :slight_smile:


(James storie) #9

Haha, I was going to say that I believe a big part of autophagy has to do with this calorie need that the fat can’t keep up with, but what you said definitely sounds a lot better! :smile:


(Dustin Cade) #10

@jamestorie @Richard does have a way of making hard to understand information, easier to understand…


(Richard Morris) #11

This is what the protein insulin looks like when it is made, it’s looks like some weird accident involving a kaleidoscope, and an Olympic ribbon competition.

Any of those twists and turns bend in slightly the wrong direction and it stops being able to perform it’s designated function. So it makes sense that we have a process to greedily scavenge the weirdly shaped ones, break them apart and rebuild them. Fasting just kicks that up a notch.


(eat more) #12

at Christmas time LOL


(Dustin Cade) #13

my thoughts exactly!!


(Crow T. Robot) #14

Is there any basis to think that a different number might be obtained if fat-adapted subjects were studied?

I do notice that fasting gets easier the more often you do it, could the body adapt to release more energy from fat stores with practice?


(Richard Morris) #15

That is always a possibility, although a few lean people who had problems fasting, and tried the calculator I built were able to fast when they supplemented with sufficient dietary fat to supply the arrears - which might indicate that being fat adapted (as these people were long term ketoers) doesn’t appear to lower that limit.

Two things that people think MAY cause adipose tissue to release energy at a higher rate are Caffeine and Ephedrine. I’m also on the lookout for anyone who has looked into those, or other stimulants.


(Meeping up the Science!) #16

You called?

Huh, this was also (somewhat) related and interesting.


(Richard Morris) #17

You are awesome Donna thank you … and it’s not even my birthday. :birthday:

I wish we knew the mechanism for a limit on fat cells releasing energy, rather than just the observation. < Pausing to see if the Donna genie delivers on that wish too >

Those studies propose a mechanism that caffeine affects lipid mobilization by affecting how the CNS signals adipose tissue. If that is correct, and that is the only mechanism by which caffeine stimulates lipid mobilization then caffeine might not be a candidate for changing the maximum rate.

To test that I think we’d need a lean person, pushed to test their maximum rate of free fatty acids. Then give them a shot of caffeine and see if the FFA doubles.

The fact that Alpert found that the limit correlated with fat mass indicates that it is likely an attribute of the adipocyte. I suspect the above experiment wouldn’t show a blip.


(Meeping up the Science!) #18

It would be interesting if irisin or UCP1 somehow were used regarding limits (as an adjunct to their typical functions), but I don’t recall any research off-hand. One of the “positive” sides to Vyvanse being utilized for binge eating disorder is they are starting to investigate stimulants in general more. I mean, someone has to have tested the limit mechanism? Well, maybe not. I’m at work but I’ll look at home.

As a throwback tangent to your earlier post, folks might find this useful. It’s an interesting (if brief) general review of various stimulant and non-stimulant thermodynamics.


(Mary Ann) #19

Exactly-- this is the part that is worth teasing out. I hope some folks are on this track.