Why people say fat adapted

#1

Why do slot of people on this forum and various other places talk about being fat adapted ,surely you either burn fat or you don’t ,if someone eats a normal diet with carbs but at a calorie deficit then they will burn fat for fuel ,how can they be any less 'effecient 'at burning fat for fuel than someone on keto ,if you don’t eat carbs for a few days then you must be burning fat for fuel ,so why do people say it takes weeks to become adapted ,it’s something I’ve never really understood,I’m no newbie to keto I’ve been on it 5+ years just can’t get my head around this

(KCKO, KCFO) #2

Can’t speak for everyone but for me, it means my body prefers to use the fat. I can slip in and out of ketosis, we all do to some extent, but now, I slip back more easily and much more quickly. Also not experiencing any of the side effects, like lack of electrolytes when you’re adapted.

Looking forward to seeing the other responses.

(K-9 Handler/Trainer, PSD/EP Specialist, Veteran) #3

My body has adapted to burning fat primarily, instead of carbs. Hence, the term fat-adapted. Most people who grew up with grains… sugar… the refined stuff, typically served for the last 50+ years, are not. They’ll store the extra calories as fat, hold that fat, and at the first opportunity, burn the glucose instead.
It takes me at the longest, the next day and I’ll be in ketosis again.

My body prefers burning my body fat first.

(Joey) #4

@Wotters My understanding is that, yes, your body can metabolize SOME fat even while we’re heavily into a carb diet … but not much. So it’s not 100% all or nothing. But, as long as we’re loading up on dietary carbs, the fat burning is minimal at best. Hence our bodies store most of the fat for the proverbial rainy day.

It takes a while for the various components of your body’s overall system to adjust - including the initial keto flu withdrawal process when you highly restrict dietary carbs. But even after those initial symptoms subside, you’re still not yet fully exploiting the fat-burning potential (hence extra AcAc in the urine for a while) as both the supply and demand sides of the metabolic equation begin to settle in together to an efficient balancing point.

While that initial rough patch for most falls within those first first few days/week or so, it take more time for your entire system (liver, kidneys, heart, brain, muscles…) to shift over to rely on a steady source of ketone/fatty acids as fuel - and then only use glucose (produced via gluconeogenesis of fat) secondarily.

In short, it’s not like an on-off switch is being flipped inside your body. There are a lot of “moving parts” that make adjustments in a dynamic way that interrelate and affect each other as the longer-term process of transition unfolds.

If anyone with a more advanced understanding (which isn’t asking for much in my case) can set things straight, thank you in advance!

(Bacon is a many-splendoured thing) #5

It’s for a biochemical reason. Bear with me, this might be a bit long-winded.

Glucose, while necessary at a certain level in the body (about 4 or 5 grams is circulating in your bloodstream at any given time), is toxic when the level in our blood rises too high. It causes damage, and if it gets high enough it can actually kill us. So when the level of glucose rises, say after we eat a lot of carbohydrate, the pancreas manufactures insulin to drive the excess glucose out of the blood and into muscle cells, which burn it for fuel, and fat cells, which store it in the form of fat.

When we continually feed on high amounts of carbohydrate, the muscle cells are kept so busy metabolising glucose that they never get a chance to use fat—not to mention that the high insulin is keeping all the fat inside the fat tissue, anyway. So the muscle cells end up powering down the “machinery” that metabolises fatty acids—no sense keeping it going when there’s no work for it to do.

When we cut our carbohydrate intake to ketogenic levels, the muscles quickly run out of glucose (within a day, usually) and start burning ketone bodies instead. But they are not really happy about using ketones, so we experience a drop in endurance and performance. This period only lasts, however, as long as it takes for the muscle cells to power up their fat-burning “machinery” again. This process generally takes around 6-8 weeks, and at the end of it, we have our power and endurance back, because our muscles are happily burning fatty acids again.

Fat-adaptation is not an on-off switch, but a gradual process. As bits of our muscle machinery come back on line, our energy and endurance start to come back, too. But there’s usually a point at which people sort of realize that, hey! I have my energy back! And that’s how we know we’re fat-adapted.

Hope that helps.

(Cancer Fighting Ketovore :)) #6

To illustrate a point…
I had an RMR (resting metabolic rate) study done in April and again in July. Here are the results:

April

IMG_20190815_203136446
IMG_20190815_203136446.jpg3024×4032 2.85 MB

July

IMG_20190815_203841252
IMG_20190815_203841252.jpg3024×4032 3.98 MB

This shows that in April I was essential just using fat that I ate too fuel my body. In July I was still primarily using fat, just a little less so than before.

When we talk about fat adaption we are talking about the respiratory exchange ratio. There closer to 0.70 the more fat adapted you are. A person who primarily fields their body with carbs will have a ratio closer to 1.0

(Rebecca 🌸 Frankenfluffy) #7

Terrific explanation, Paul! Really helpful!

#8

hey @PaulL im in no way trying to discredit the keto movement or.way of life like i said im in keto 5 years plus ive lost 4 stone in weight , but the bit when you say having excess carbs will not allow you to burn fat has to be incorrect if you are at a calorie deficit, the science is rock stone solid if i eat at a calorie deficit i will lose weight , so my question still remains , if every study done to date proves that , there is no difference from someone burning there own fat from calorie defficit to someone burning fat from being in a carb deficit , how can there be a 'fat adapative ’ stage it still seems nonsense ?

#9

and the other point is i can eat a absol;utely huge carb heavy meal , and if i fast for 30 + hours i am deep in ketosis according to blood monitor
without any adaptation period

#10

yes but if they eat less calories than they need they still burn fat , my question is why is your version of burning fat more effecient than theirs surely they are using the same process

#11

you say not much , but every study done to date confirms that eating at a calorie defficit burns the same as eating a low carb diet

(John) #12

From my own personal observation on my journey so far, the difference was in how I felt in the absence of plenty of carbs as a fuel source.

So perhaps it was a gradual increase in how effectively my body was willing to burn stored fat for fuel, and my body to be able to use that fuel to run all daily processes without me feeling tired, fatigued, or sluggish at times.

Probably about week 4 in the process is when I started to feel an upswing in a perception of generally available energy, and by week 12 I pretty much felt “normal” all day long, no matter when or how much I ate, or whether I had eaten anything at all. That is when I think I was “fat adapted” for lack of a better term.

I think in generally metabolically healthy people who are at a stable weight, sure, they go in and out of fat burning every day. In particular, when they are asleep and there is no steady source of incoming food energy.

And that is one of the goals of a ketogenic diet - to reverse the effects of a “carbs as primary fuel” and get your body re-adapted to switching back and forth between carbs and fat for energy seamlessly.

So to me, re-establishing the healthy metabolic state is really what the whole way of eating is about. Once that is accomplished, THEN things like mild caloric restriction and increases in exercise can have the expected results.

(Kath Galvin) #13

I can only say how different I feel after building my fat burning ability over the last year or so. I no longer have blood sugar spikes or drops, no hanger and very slow rise in hunger. I feel fueled by clean energy, like I went from diesel-fueled to solar-powered. :sun_with_face:

(Robert C) #14

That is a definition but it is not very useful (calories in and out are not calculable).

The problem that you are overlooking is that if:

  • Your metabolism is wrecked - a 2000 calorie meal is potentially 500 calories more than you can burn in a day (forcing you to store body fat)
  • Your metabolism is fat adapted - a 2000 calorie meal is potentially 500 calories less than you will burn in a day (forcing you to burn local body fat)

Same “you” - just a non-fat adapted slow metabolism vs. a fat burning machine.

Yes, after 30+ hours of fasting, you get ketosis numbers but, to do that, you had to go through a lot of hunger compared to a fat adapted person.

As well, it is not just the arrival at the endpoint that is important. The fat adapted person that had the Keto meal has their liver burning fat and producing ketones almost from the beginning of that 30+ hour fast. The person that had the big carby meal won’t start burning fat until all of the dietary glucose has cleared and all of the glucose from the body has cleared - many hours into that 30+ hour fast.

Same calories in - very different body fat burn.

#15

but my argument is people lose weight ( my brother forv example ) has lost loads of weight by cutting his calorie intake , hes done nothing but cut calories he weighs everything , … hes still burnt fat at a rate , that equals that being in ketosis , the same as every scientific study show , if you eat at a calorific deficency you will lose weight its indesputaqble , so my question is why is being fat adapated any more better than someone who eats at at a callorie defficet but still loses the same amount of weight as someone on keto ?

#16

but every proper study shows that they lose weight at the same amount

(Robert C) #17
  • Yes - if you eat at a deficit - you will lose weight - not disputable.
  • Yes - if you eat at a deficit - your body will adjust metabolism down (simply slow it) to the new normal intake - not disputable.
  • Yes - you will eventually stop your weight loss at that same low calorie level - not disputable
  • Yes - you will further reduce your intake to continue weight loss - not disputable
  • Yes - your metabolism will slow further - not disputable
  • Yes - you will hit too low of a calorie level for too long and burn out on your calorie restriction based diet (having killed your metabolism) - not disputable
  • Yes - you will gain weight and, due to your slower metabolism - more than what you lost - not disputable

The rate of loss, bounce off of a ruined metabolism and increased regain is a very high percentage for non-Keto calorie restricted diets (I have heard 95% plus and up to 99% plus).

#18

but adding in a day of over calories stops the metabolic slow down

#19

listen i am absolutley on the low carb wagon , but i have some major flaws in OUR argument when discussing this way of life with a very clever guy , who has studied nutrition for many years , so dont go beating me up im just putting his arguments to US as a community wich i trhink is a good thing

(Robert C) #20

This is simply wrong and I don’t know where you think you are getting your "proper study"s from.

Take a moment to think about it:

I give a fat adapted person 1000 calories of butter to eat for the day - they will store some of that butter as body fat.

I give a fat adapted person 1000 calories of butter to eat for the day - but, I also inject them with insulin - they will store a lot more of that butter as body fat.

Same calories in - hormones determine storage - carbs increase the hormone (insulin) that determines storage.

This is a very common complaint of diabetics that start insulin - substantial weight gain with little or now dietary (i.e. calorie input) change.