Why would my metabolism slow down if I’m getting cals from fat stores?

(Alec) #121

That so reminds me of this wonderful cartoon… [credit to @atomicspacebunny who posted it in humour]


(Neil) #122

@daddyoh, the way I read your BG test results is that your meal didn’t really produce any noticeable insulin response at all – which is what I’d expect given that it sounds like it had very very few carbs! Keto at its finest. :slight_smile:

(Eric - NSV count!) #123

Yes that is my interpretation. Also as mentioned my midday BG levels are below 90 which is good for this old man’s body.

(Wendy) #124

So reading this encourages me. I’m only 54 but I am also having trouble NOT losing weight.
I don’t know how many calories or any macros I’m eating but maybe I just need to eat more. I’m 5’6" and 119 today. My goal was 132 so I’ve lost an additional 13 pounds. I do go up and down five pounds while not doing anything purposely different.
I started around 200 pounds about a year and a half ago. I’m also sure I have lost some muscle. :slightly_frowning_face: But haven’t worked out.
So I guess time will tell if I maintain or gain. But I think I need to eat more than I am.

(Michael - Don't expect miracles and you won't be disappointed.) #125

Thank you for saying so, hopefully you will resolve things successfully. :wink: Have you posted what you’re eating anywhere on the forum? Anyone who wants to try to advise what and how much to eat specifically will need to know that info to help. But generally, from my experience, if you want to stop losing weight eat more fat and protein. At some point the weight loss will stop, and it may take a lot more food than you think! Whether you want to continue to follow the advice of a lot of people on the forum not to bother to track macros and calories, or if you decide that doing so would be helpful is up to you. Either way, keep the carbs sub-20 and just eat a little more each week until the loss stops. It will. If you think you’ve also lost muscle mass then eat more protein.

(Wendy) #126

I could share what I eat but it varies day to day. Somedays I’m hungrier than others so I’ll eat more. Sometimes I eat a large steak with mushrooms and broccoli, somedays I eat several deviled eggs. I eat twice a day, I eat once a day occasionally. I even eat three times a day at times. So I’m not sure logging or sharing will help too much
But I will try to eat a bit more or at least try to eat more more often.
I did have icecream yesterday. :grin:
I don’t “cheat” much but I am not afraid of fat and add butter and fat to my diet freely.
I am definitely not a tracker. I’m just not that disciplined.

(PJ) #127

In the interests of not making a zillion separate posts, I read the thread and all my responses are in one.

If the caloric limit is by some miracle exactly what the body needs that day, then the metabolic rate remains normal, and the body is happy.

Yeah like that’s easy :rofl: That reminds me of one of my favorite comics ever:

If fasting slowed our metabolism, we’d never have survived going out to hunt, right?

After reading and watching Fung, and then trying to explain it to my best friend on the phone, I found myself using this analogy:

UNDER-eating makes you a "competitive eater." There’s not much food. You need more of it. Your appetite goes up… people get sneaky when they’re hungry. They get sly in order to get more of things – they steal, they ingratiate themselves with those in power – all behaviors driven by increased hunger – in other words, they compete with other people for limited available resources (food). The metabolism goes down: you have to survive until Spring.

NOT-eating makes you a "competitive hunter." For your own survival as well as your tribe/clan you have to outwit and outfight your prey to survive. Your brain function gains clarity for survival planning and strategy. Your body taps on its own energy stores for strength and endurance in the stalk and in the fight. In other words: Your metabolism goes UP to make you more competent as a hunter SO that you (and your tribe) can survive until Spring.

Many people are “eating to satiety” (#4) and this lowers their caloric intake (#3)–that’s why they’re losing weight and aren’t hungry, but their metabolic rate is also dropping. Or they’re “eating to satiety” and not losing or gaining (#1), because that generalized guideline isn’t lowering their intake enough to where they start tapping into stored energy. “Eating to satiety” is a nice representative mental state, but it doesn’t necessarily tell you anything about someone’s energy intake.

I agree with this. I ate ‘to satiation’ and even well past it when I first did keto. And I profoundly underate, lost 170# very rapidly, and most of my hair fell out.

This belief in appetite regulation requires a nearly faith-element that massive chemical abuse by the pseudofood supply every day pretty much our entire lives from toddler on, has not forked up our satiety signals – and that ketogenic state’s natural appetite reduction won’t.

It also has the unfortunate effect of shifting objective biochemistry response which due to our creaturehood feel subjective, back to some ineffable and amorpheous moral-quality of the individual (a subtle vibe of ‘gluttonous vs anorexic’), something corporate-food and its marketing try hard to keep in focus I might add, and far away from research and understanding about how the most critical things, ‘appetite’ and ‘satiation’, are affected – and mercenarily managed in the $ case – by food.

When they fed cows coconut oil, they had more energy and they lost bodyfat. This was completely without regard to their relationship with their mother. But human food paradigms would have us believe that how human bodies react to the ‘food’ supply is all about subjective feelings.

I get that SOME people – rare unicorns among us :slight_smile: – have a less-damaged metabolism and appetite signals and can literally eat to satiety and they are fine. But I suspect that these people are the exception, not the norm, at least if we are grouping mostly the people who want to eat lowcarb for fat loss reasons.

So if you keep your energy intake high enough to prevent weight loss, there’s nothing inherent about keto that would cause it to drop. Which is good confirmation.

Yes, but the note about IGF-1 decreasing independently is not good (from that study). I mean it’s nice it didn’t seem to affect REE but these kids growth was stunted, essentially, that’s what it was saying, right. So still there is something going on, although perhaps it doesn’t affect our metabolism discussion.

I take these 2 studies together to mean that endogenous release of FFA has the same effect as adding fat into the system. Total energy is maintained.

I hope it means that. Given that we are essentially animals (mammals) and our bodies create saturated fat, how would our brain know fat is ours vs. our steak’s, unless of course it recognizes our unique signature somehow.

I am no scientific genius–quite the opposite–but I read the studies I referenced to say that metabolism dropped when intake dropped. Even the obese people (who would have plenty of fat stores to add to total intake) in these studies experienced metabolism drops on keto diets.

True and I am glad you call this out (despite its un-PC unpopularity LOL). The important thing is not the data but the conclusion. If that’s the data then it suggests something is going on but it doesn’t have to be that “keto is harmful to metabolism,” it might very well be that “overweight and obese people are almost always insulin resistant and this improves but doesn’t totally resolve overnight.”

Especially since being hyperinsulinemic is not the same as being insulin-resistant although they are correlated of course, and even solving the latter doesn’t mean you’ve already solved the former, which can be present even without signs of IR in ordinary glucose tolerance tests (and long before).

And I might add, the insulin problem (separate from glucose) interferes with leptin – an appetite/satiety signal.

The result possibly being that we pay attention to the wording, as I notice @Karim_Wassef seems to try to be – it is about ACCESS to the fat, not merely whether the fat exists.

I think this is really important, because deciding it means a diet reduces metabolism just leads to “bummer, man” but deciding it MIGHT mean that access /interference is happening may lead to more research and perhaps even some solution or improvement in this area.

When I read the collective wisdom of these threads, I am simply amazed that our ancestors managed to survive. How did they do it, with no supplements, without equipment to measure their BMR, no blood meters, without even the least knowledge of what a calorie is? Obviously, we would all just drop dead if we relied on our bodies to handle things without supervision . . . .:rofl::rofl::rofl:

Funny! I think back then, getting fat in the fall on all those berries and honey was probably more likely to make Grita say, “Grok you’re looking hot with that little pot belly!”

Expressed relative to body mass (kilojoules per kilogram), REE was not significantly affected by the VLCKD (2.3%) or low-fat diet ( -5.7%).

That’s a happy finding. I don’t think the 2.3% is enough to be statistically significant but still it’s a warm fuzzy feeling that it’s a positive number. :smiley:



Yes. I think the tendancy to overeat is reduced from an imperative signal to dull background noise for most people going from carb to keto. Not everyone will experience this, at least not right away, maybe never. It also doesn’t take into account emotional-based eating and other psychological aspects that aren’t food based.


Yes, for starters, I think we’re mostly talking about metabolism here. Since we don’t have studies specifically on that topic, we’re looking at stand-ins.

As for the kids and growth in that study, it may open up a whole new avenue of debate, but I think it’s important to remember that they’re on a medically ketogenic diet for epilepsy. Those diets tend to be low protein, so it makes sense that kids were not growing as they might otherwise. People who are on a nutritionally ketogenic/very low carb diet should be eating sufficient protein, so the same concern does arise. There is no need to restrict protein just for the sake of hitting a certain macro percentage, as there is with the medical diet for epilepsy.

(PJ) #130

Ah yes, excellent point – the low protein – I had forgotten that entirely, thanks!

I also hadn’t thought until after the post about the fact that IGF-1 though normally good (growth hormone yay) is possibly dose dependent. A lot of things seem to have a point where higher doses begin to not work as well and eventually can do harm.

Quote from a random blog:

insulin-growth factor 1 (IGF-1), which at high levels can contribute to insulin resistance, and potentially rids the body of inflammatory, ill-functioning senescent cells, which in turn can improve cellular functioning and metabolic flexibility (the ability of cells to switch seamlessly between fuel sources such as sugars and fats) in aging tissues.

Possibly IGF-1 reduction was merely reducing it to what should be normal; or was a result of the low protein; but in any case seems possibly related to lower growth pattern, but might relate not to keto but to the low protein.

(Give me bacon, or give me death.) #131

The brain doesn’t know, that’s the point. But the low insulin level resulting from minimal carbohydrate intake allows fat cells to release fatty acids into the bloodstream. These then become available to be metabolised. The low insulin level also permits leptin, secreted by the fat cells when they are full, to be received by the brain again (high levels of insulin block off the brain’s leptin receptors), so that the brain knows there is an abundance of available energy. The brain then shuts off the secretion of ghrelin, the main hunger hormone, and secretes other hormones that tell us we are not hungry. So it really does not matter where the fat comes from, it is available to be metabolised. As long as insulin remains low, excess fat in the fat cells is included with the fat available to be metabolised. And of course, when the available fatty acid drops below a certain level, the fat tissue stops secreting leptin, and the brain activates the secretion of ghrelin to make us hungry again.


Interesting thread. Two comments:

  1. Regarding reduced metabolism: in addition to less metabolism due to having to carry less weight, it is supposed keto should induce a “partial fasting”, so organs should contract. This would be essential for future autophagy. Then, this reduced metabolism would be at least partly benefitial, no?
  2. For the time being, my medically-controlled high-protein-keto diet is working really well. The amount of protein (from soy mostly) is at normal levels, but both fats and carbs are set at very low levels. I am severely calorie restricted, but without hunger. I do not have the feeling my metabolism is slowing down at all. Could it be that eating “normal” protein, while reducing fat (inducing own fat consumption) and carbs (low insulin, leading to switch towards a “anti-fat-storage” mode) is optimal?


As I understand it, autophagy is a function of protein restriction so a fat-only fast would be preferential to a protein-sparing fast for this purpose.

I’m not sure what you mean by reducing fat “including own fat consumption”?

Assuming you are not creating excess insulin because of IR or T2D and thus limiting the release of fatty acids from your adipose tissue…
IF you are able to meet daily energy requirements by using your own fat, then reducing dietary fat shouldn’t change your metabolism for the worse, beyond the effects of reduced bodyweight on energy expenditure. If your hunger signals are working correctly, that is. Some people might experience an anorexic effect? So, rule of thumb: take estimated number of pounds of bodyfat x 30 kCal and use that as a maximum you’re getting from your own stores to be on the safe side.

Sometimes a short period of overfeeding can jump start a higher metabolic rate, and get past a stall. Or alternate fasting and feeding can do the trick.

Some warnings signs of slowing metabolism are cold feet or hands, tiredness, hunger or specific food cravings.

(Eric - NSV count!) #134


Or both. Mix it up.

You can get cold on extended fasts, especially at night. I’m not sure why but I think it is because for me I expel fluids. (I pee a lot of fluids out). As soon as I refeed this goes away.

(Doug) #135

If you’re aiming at weight loss, it sounds really good to me. The body’s response to protein while on a ketogenic diet is much different than if a lot of carbs are eaten, i.e. vastly less insulin response. You’re evidently getting plenty of energy from burning your own fat, and feeling pretty good.

Protein digestion consumes a meaningful portion of energy, moreso than for carbs and fat. The ‘thermic effect of feeding’ for the protein in some meats is as high as 35%, i.e. it takes a good third of the energy contained just to digest it.

I see the following study, where soy protein averaged a peak 24% increase in oxygen uptake after eating it :


Day by day this is not a huge influence - it’s only while protein digestion is going on.

Or is it? Just my own experience here - there have been multiple days where the only thing I ate was something like a container or two of sardines and a piece of cheese. We’re talking 400-600 calories, probably, in the afternoon or early evening. Should be no big deal, but then later on I feel increasingly energetic and warmer, and it continues through the night, sweaty pillow and all.

It does not do it every time, so I don’t really know what’s going on. What I want is fat loss, so I’m glad of it - and more convinced than ever that protein, per se, is not to be feared when eating keto.

Over the long term, it’s a good question - what really is “optimal”? Different people will experience different things. I wish we knew when the average person would get a metabolic slowdown from calorie restriction.

From the ‘Biggest Loser’ contestants and things like Keys’ Minnesota Starvation Experiment we know that in 5 or 6 months, the metabolism can be slowed. For those with adequate stored fat and access to it, I’m not sure there would be a slowdown, and some who have fasted for very long periods seem to not suffer from it, other than what stems from overall decreasing body weight and the lack of energy expenditure for digesting food.

While some people do feel cold while fasting, I don’t think that in a week or two the metabolism is going to be really much affected, i.e. after they start eating again, they’re like they were before. So somewhere out there in time, a month, two, three, four - is where I’m guessing the time for slowdown is, if calorie restriction is what’s driving it.

@Arbre - how long have you been on your current diet?

(Tammy) #136

Hi Sharon, it is well worth the investment to get Dr. Fung’s books “The Obesity Code” & “The Diabetes Code”. (I just finished my second reading of them.) Both of these books have been a wealth of information for me. They are very well written for the average person. Not a while lot of scientific jargon, but explained simply. Read Obesity Code first, then Diabetes Code. Whether we have a diagnosis of diabetes or not (which I did not have, but still quite sure I was insulin resistant), the info hit me like a bolt of lightning! He very sussenctly explains how our metabolism slows as our weight drops. It’s our body’s safety mechanism from starvation mode. Nothing to worry about or beat ourselves up over. Just takes longer to lose those pesky last 20 lbs or so as we get closer to the prize, our goal. #KeepCalmAndKetoOn sister!

(Karen) #137

So if I weigh 165 pounds, and 26% of that is currently fat, and I can get 30 kcal per pound then… I should be able to get 1287 cal from my own body fat. That seems like a lot. Are you sure it’s not kilocalories per kilogram? For me that would mean a lot of calorie restriction to lose any weight at all . And maybe that’s actually true. Please verify, thanks

(Give me bacon, or give me death.) #138

Yep, 165 lb. x .26 x 31.5 (k)cal/lb. (a bit more, actually, than the 30 you were quoting) = 1331.35 (k)cal. Which is why Phinney and Volek found that people in the induction phase of a ketogenic diet who eat to satiety typically eat around 1000 (k)cal less than their energy needs, because their appetite is set at a level that allows the “missing” 1000 (k)cal to come from stored fat. I’m not sure where “calorie restriction” comes into the picture, because you are not restricting calories if your body is telling you to stop eating because you don’t need more food.

Note that there is a minimum level of fat that the body wants to retain. In the case of women it’s in the range of 21-23% of total weight, in the case of men around 10-13%. (Women need a larger fat reserve, of course, to support pregnancy and lactation.) As we approach this in-built limit, the amount of fat the body considers excess shrinks, the caloric contribution from dietary must increase (it does so automatically if we continue to eat to satiety), and fat loss slows and eventually ceases.

I highly recommend reading through the following thread, in which @richard explains the issues at length:


@OldDoug I have started my second keto diet (the first one went well, and I maintained my weight for a few years; then I regained them, after a change in my lifestyle) recently.

I remember from my first keto diet that when I lost most of my weight, I was colder than usual in winter.

But I was giving the responsibility to the lack of fat, which naturally acts as a “coat”. Of course, it could be both: the loss of the “fat coat” and the reduction of metabolism.

But even in the case of reduction of metabolism, we should differentiate between absolute reductions (e.g. less muscle is needed to carry the body, less blood pressure is needed …) which in general are “good” from relative reductions (e.g. is the internally generated heat lower than in the case of a “healthy” person, with a stable weight and BMI similar to the ketoer?).

Even though relative reductions may exist, I would like to see the numbers and compare them with the absolute reductions. My intuition is they are not very meaningful. I think most of the reductions are healthy (less blood pressure, less muscle to carry the weight …).

(Karen) #140

Well if I look at a number of calculators to see would a woman of my age and sedentary lifestyle needs to eat by way of calories I come up with somewhere between 1400 and 1500 cal. (I’m 63, I weigh 165 lb, I have 26% body fat, and I have a sedentary lifestyle)

If I can pull almost 1300 cal from my own body fat then I pretty much need to be fasting all the time to lose ANY weight. I will tell you right now that I eat somewhere around 1300 to 1500 cal. I stay below 20 cal, sometimes below 20 total calories, of carbohydrates. I have increased my protein, and reduced my plate fat. The “eating to fat to satiety” is more fat than I normally allow myself to eat. I could probably eat more fat but I’m trying to help my body eat my own fat. I have stayed at about 165 pounds for a solid year.

Either I need to fast, a lot, or maybe just lean protein, no carbs and no fat.

Thank you for the article I will re-read it