Is it true that metabolism can slow on keto if I have lots of fat to lose?

#1

Can metabolism slow on keto if you have lots of fat to lose?

I’ve seen this stated on several Keto forums and it always strikes me wrong. If a person, me for instance, is eating a few hundred calories below maintenance (below 20 net carbs and I watch my macros carefully), and has a lot of body fat to lose, why would my metabolism slow?

If I’m fat adapted (in my case I’ve been strict keto since July 26, 2018), then shouldn’t my body be able to meet all of it’s energy needs from body fat? Is there something I am missing? (FYI, my start weight was 350 and I weigh 261 today, so I still have a LOT of fat!) Wouldn’t that only apply to someone who doesn’t have much fat to lose? Just curious.

I wonder if I am missing something. My own weight loss has slowed dramatically, but I think my body is healing and I really, really hope the weight drop picks back up soon. Anyway, I’m always looking for ways to keep the weight dropping.

Do you think metabolism slowing is an issue for fat adapted fat people like me?

(You've tried everything else; why not try bacon?) #2

Even in the absence of carbohydrate, famine conditions encourage the body to hang on to all its resources and cut back on nonessential expenditures (hair growth, the reproductive system, etc.) to get through the hard times.

By contrast, fasting doesn’t trigger this reaction. It makes sense if you think about it—a hunting community would naturally go through cycles of fasting and feasting, and since we haven’t noticed any fridges in most paleolithic archaeological digs, they would have been limited to only the amount of meat that they could eat before it all spoiled. Then they wouldn’t have any more until the hunters returned with another carcass. You certainly wouldn’t want your hunters to have low energy while stalking cave bears or woolly mammoths. To say nothing of chasing down antelopes or gazelles.

In any case, this is why we recommend eating to satiety. The body sets our appetite at the correct level to use both stored and dietary fat, without our having to calculate calories at all. Setting an arbitrary caloric intake runs the risk of setting it too low and triggering the famine reflex.

(Scott) #3

From what I know metabolism slows during calorie deficit or the body perceiving starvation. What I don’t know is if fat adaption makes up for the calorie deficit to bypass this slow down. I was going to defer to Paul but he beat me to it.

#4

Hummm… Well, I’m never hungry. I stopped feeling hungry just a couple of weeks into low carb. That’s when I switched to eating two meals a day. Since early on I’ve been eating around 3 pm and again at 8 pm with my husband and children.

My problem has always been that I love eating and would just eat because it was there. Now I forget about food and remind myself to eat. I have to plan to eat. Sometimes I forget. But I have difficulty getting enough food and nutrients in if I only eat OMAD, so that’s why I try to eat twice a day.

I guess I have been wondering about metabolism since my weight loss has slowed so much. Some weeks nothing changes, others I drop a pound. I have tried eating more from time to time to see if that helps, but it doesn’t seem to make a difference any more.

I haven’t seen any studies done on keto and metabolism, but would love to read them if they are out there. I read a LOT of studies pertaining to keto, heart health, insulin resistance, etc.

I’ve been reluctant to fast since I had blood pressure spikes and rapid heart rate issues four months into this way of eating. It terrified me. More magnesium and potassium helped and it went away, but my bp is still a high (not nearly like during the spikes).

I’m also intrigued by comments that we don’t need to take as many electrolytes after we are fat adapted. Due to my experience, I am reluctant to reduce my supplements. Perhaps I just have further to go to heal my body before I can relax. I still have a lot of weight to lose!

Thank you for your input!

#5

RclauseScott

33m

“From what I know metabolism slows during calorie deficit or the body perceiving starvation. What I don’t know is if fat adaption makes up for the calorie deficit to bypass this slow down. I was going to defer to Paul but he beat me to it.”

Yes. Since my body should be able to access all the energy it needs from my ample fat stores, why would it ever perceive “starvation”?

(Scott) #6

I think you are doing fantastic. We started about the same time and I lost 20 pounds right away but stalled in mid November. I have just watched a waited but now I am just starting to tweak a few things to see what happens next.

#7

I also have quite a lot of weight to lose and am worried about metabolism slowing. However, if you think about it from the perspective of your body as an animal/product of evolution, here is what I think is happening: in nature, “rapid” weight loss is a sign of danger. For survival, our bodies and brains seek homeostasis above all. That means KEEP EVERYTHING THE SAME. So, when our energy input goes down, our energy output goes down. It’s how our bodies keep us safe. It doesn’t know that we want all this fat gone asap and are basically trying to starve to do so. It thinks “well, this is a lean season because we aren’t getting much, so we better hold on.”

I think this is why some people have more success shifting fat when they fast/feast after fat adaptation. This tells the body that this isn’t actually a lean season at all, and to burn body fat for energy until the next feast happens.

This is my opinion.

#8

It doesn’t matter how much fat you have on you, if your body can’t access it, it won’t get to it. If your fasting insulin levels are high, it won’t be able to access your fat stores. This is why obese people are frequently “starving,” because they constantly have high levels of insulin floating around. And the only way to bring insulin down is to not eat. You can do some damage control while eating by choosing foods with low insulinogenic responses (hence low carb, moderate protein, high fat). But it’s still going to take at least four hours for insulin levels to go back down.

So the best bet is to not count calories, eat only when hungry, and eat until you’re satisfied so you can go long hours between meals.

(Raj Seth) #9

I had the same experience. Old style hunger disappeared. I have realized that my brain is still making me eat quantities like I used to eat. I just feel overfull and blechh bloated whenever I am not fasting.
So now, I am on a quest to recalibrate my eyes to the amount of food I am going to eat. Just last night, I sat down to dinner with the family, had one bite of my chuck steak, and a bite of my pulled beef, and felt full. I had had some bacon jerky and a bag of pork rinds an hour earlier - which was the likely culprit. As I said it, and put another forkful in my mouth - my teenage daughter said “Just stop eating Dad!”
Such simple advice. I did, and felt great all evening and night. BTW, I had not eaten anything since dinner the day prior.

That ramble aside, just eat to true hunger, and keep it mixed up, and your body will let you know what it wants and your metabolism should not suffer. If you go through a phase where the body does not want to reduce fat stores for a bit, you will likely have more hunger - not the old style carb-fed hangry, but the new improved keto true hunger.

As for forcing 2 meals a day because you can’t get enough “food & nutrients” in doing OMAD - don’t worry about it - your body will let you know
As for slowing metabolism - are you cold, lethargic, listless? If not, likely your metabolism is fine.

(Omar) #10

a loaded truck will consume more gas than when it is unloaded for performing the same job.

when losing weight you will have a smaller version of your self and naturally your body energy expenditure becomes less. But this is not bad thing. So if you keep eating the same calories after losing weight as the amount of calories before losing weight, it should not be surprising to observe a weight stall.

#11

No, I’m not cold, lethargic or listless. I have more energy than I have had in years. In fact I have finally gotten around to unpacking boxes I left untouched when we moved several years ago! smile: I have been slowly increasing my walking, but because of my weight I don’t want to over-do it too quickly.

I feel as though I am participating in life more fully now since I am not tired like I used to be all the time. I’m only going on my 7th month eating this way and love it! It is just that a few months ago I had two weeks where my bp and heart rate really spiked and that has me frightened and has left me cautious.

#12

I agree. I have reduced my food intake some since I have started because of my weight loss, but I don’t want to go too low. I may try OMAD again, but it was what I was doing when I had those crazy heart rate spikes and bp spikes. I am pretty sure it was all because of a magnesium deficiency, but I’m a bit skiddish about changing things too much too quickly.

I think I would still like to find studies where low carb and metabolism were studies, but I haven’t found any. I’m probably going to increase my walking a bit. I’ve been very sedentary for a long time, so I know my body needs a lot of repairs.

#13

Some days I eat lunch and I’m not hungry for dinner. Other days I need 2 meals. I plan for 2 but sometimes my body only wants/needs one.

#14

And (from what I’ve read) the reality for those of us with a lot of extra adipose tissue is this: even when we control our insulin as much as possible, we still have more insulin circulating than if we didn’t have all that extra fat. That means when we eat it goes up higher, and when it “recedes” it’s still at a higher level. Right?

So, doesn’t this mean fasting can be more useful, not because of calorie reduction, but because of its potential for re-setting insulin sensitivity? I don’t want to get embroiled in the “do calories matter” argument, but I honestly am surprised at how much people depend on that weirdly arbitrary number to determine their energy intake.

#15

Thanks for your imput! I only refer to calories because it is something people are familiar with even though it isn’t really accurate.
A few months ago I had my a1c tested and it was 5.8, pre-diabetic. But this was after 4 months of low carb. Not sure what it would be now. I don’t test my blood sugar levels and never have, but I do expect that my body is repairing damage done from too much carb intake. I know it will take a long time. I’m not sure how or if that relates to how insulin sensitive my body has become. I suspect I do have a way to go yet.
I do think fasting would be good to try, but think I need to work my way towards that by just having OMAD for a while to prove to myself my that my bp and heart rate will stay in a safe zone first.

I like to look at studies done on humans whenever I can, although I admit I don’t always thoroughly understand them. :blush:

(You've tried everything else; why not try bacon?) #16

While too much insulin can make us fat, by forcing glucose into fat tissue, I don’t think the presence of fat in fat tissue causes the pancreas to secrete insulin. As I understand it, insulin secretion is tied to the blood glucose level (because hyperglycemia is dangerous) and (to a lesser degree) to the amount of protein eaten.

But the response to protein is moderated by the presence or absence of carbohydrate in the diet. In the presence of carbohydrate, there is no glucagon secretion, and any risk in insulin therefore increases the insulin/glucagon ratio, and even more glucose gets stored in the fat cells. In the absence of dietary carbohydrate, if protein stimulates insulin, it also stimulates a commensurate increase in glucagon, so that the insulin/glucagon ratio remains unchanged at a low level, and fat can now be released from the fat tissue.

Dietary fat has such a minimal effect on insulin secretion that to all intents and purposes it can be considered null.

#17

Thank you PaulL!

(Vic) #18

I had lost 60 Lbs doing 18/6 most days some OMAD days, then I stalled for 2 weeks So I stopped the 18/6 and eat a bit more as I was concerned about lowering my metabolism and I began to lose wieght agian

I will proboably go back to 18/6 next week

This is the first time this has happened I am guessing the body will need this from time to time to keep metabolism going strong