Is high fat required?

[AllenB]

What if I’m eating less carbs and less fat? Also, is there such a thing as too much fat?

[SomeGuy]

What if I’m eating less carbs and less fat? Also, is there such a thing as too much fat?

Welcome to the forum. If you are getting less of carbs, protein and fat, you may being running on empty at some point.

Assuming you’re successful at not eating any meaningful amount of carbohydrates (i.e., a “ketosis-inducing” diet) then you will need to up your fat… or your body will go into starvation mode at some point and your metabolism will begin to shut down. Not good for accomplishing anything that’s heathy.

Note: your body does not need ANY dietary carbohydrates. Carbs are entirely non-essential. However, your body does need both protein and fat - and cannot independently produce either.

And since there’s only so much protein one can handle (without inviting other issues), that leaves fueling yourself on high quality (animal) fat as the primary source of energy intake to fuel your body’s needs.

Can you eat TOO much fat? Well, okay, sure - you can overdo most anything at some extreme point (see hormesis). But if you are eating fat and protein to the point of satiety, it’s pretty hard to have over-eaten fat.

That’s not really a thing. You will cease being hungry long before you eat too much fat.

Others will likely chime in with additional details, but that’s the best I can do on the fly.

[PaulL]

We recommend eating very little carbohydrate, a moderate amount of protein, and adding fat to satisfy your hunger. Protein is essential to the diet and fat is essential, there is no such thing as an essential carbohydrate.

The body’s two sources of energy are glucose (carbohydrate) and fatty acids. If you don’t eat one, you need to eat the other, or you will starve. A diet of mostly protein and very little fat is potentially fatal and is known as “rabbit starvation”–from the fur trappers on the North American frontier, who would catch and eat rabbits, but could not survive for long, because rabbit meat is too lean.

It doesn’t take as much fat to satisfy you as it does glucose. For example, 133.3 g of fat yields the same amount of energy as 300 g of carbohydrate (which is glucose molecules bonded together in various ways). This is one of the reasons fat is so satiating.

And yes, there is such a thing as too much fat, just as there is such a thing as too much protein or too much carbohydrate or too much water or . . . you get the idea. That is why we say to eat fat to satiety. Once your hunger is satisfied, stop eating. But eat enough to satisfy your hunger; don’t skimp.

[SomeGuy]

But eat enough to satisfy your hunger; don’t skimp.

This is perhaps the most difficult thing for those used to SAD (standard American diet) have to wrap their heads around … after generations of us have been scolded about eating fat - it supposedly being unhealthy.

It’s also the reason that so much of our global population is in its woefully unhealthy condition.

[Shinita]

is there such a thing as too much fat?

Of course. I am not happy when I go over 260g fat as a not very active chubby short middle-aged woman… (Even if that is very occasional.) That probably means I had almost as much protein too… I guess I would have serious problems way over 300g.
And nearly everything has a limit where it becomes fatal, even water.

What if I’m eating less carbs and less fat?

Less than what? When I went low-carb, I started to eat less carbs and less fat as I should have. I don’t know how much fat I ate on high-carb but considering I had problems for YEARS to keep below 200g* as it felt so drastically low (and I miss eating much fat since, it’s not too bad but a bit sad and it’s still too much fat), I probably had quite much. My memories tell the same.

*on most days, I mean. No way I could survive and staying sane eating less than 200g fat each and every day for a long time. It’s not much! (Too much for my body but not for my soul Okay, not soul but couldn’t resist and it’s close enough.)

But I have heard about people eating low-fat keto too. It’s not my style so I only had one such day (if low-cal days don’t count). I overate protein more than usual though. That’s not for every day… BUT some people can pull it off. Low enough energy need, high enough body fat, maybe a generous definition of “low”… Not my tendency for overeating for sure… Or my love towards fat… Low-fat means <80g for me and it works for some, at least for a while. I never figured out what low-fat means for others. If it’s percentage, well, too high protein is a problem, too low-cal is a problem, there is some decent calorie percentage we need to get from fat on a sustainable keto… But it doesn’t need to be very high. I overeat above 65% fat and I had some great days with 50% fat, I just miss fat too much there or dislike my too lean food.

[Shinita]

You will cease being hungry long before you eat too much fat.

Not with too little protein or with too many meals (like 2 in my case) and too fatty meat or dairy etc. Of course, one needs to be the right kind too.

And not everyone stops eating when hunger stops. I probably never will get the hang of it, not like I wanted that, I need my satiation (and sometimes I stop when still hungry for very good reasons)… Of course, even satiation can’t stop me all the time.
So of course some of us can overeat fat, BY FAR. It’s very hard not to overeat fat if one is me but carnivore(-ish) and a bunch of extra rules (and self-training for a few years) help a lot. I still can’t resist dairy so well but I have improved a lot. Still a long way to go.

[ffskier]

is there such a thing as too much fat?

Yes, it’s called disaster pants. Titrate your fat intake. Remove all white foods or foods that can be white from your diet. Limit or eliminate your amount of sweat fruit, such as ripe bananas and mangos. Eggs are mostly white and are an exception.
Good luck!

[Shinita]

There is no problem with white food, most of my staple items are white… Color has nothing to do with healthiness

[Skip_Cody]

This is the hardest thing for people starting this journey, though your body will take fat from your body when your not getting it from the plate, in the beginning your body has a hard time doing it. If you feel hungry or low energy, eating fat will fix that without the insulin spike.

My only advice is keep researching, the more you do the more comfortable you get with this WOE!

[PaulL]

This is the hardest thing for people starting this journey, though your body will take fat from your body when your not getting it from the plate, in the beginning your body has a hard time doing it. If you feel hungry or low energy, eating fat will fix that without the insulin spike.

Just to amplify your point, there is a limit to how much fat the body will allow to be taken from adipose tissue in one day. Richard Morris gives the calculation and the source in this post:

30 and change Calories per lb of excess fat

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 cas…

Stephen Phinney says his data (and other people’s) show that the body in ketosis can metabolise both fat from adipose tissue and fat in the diet. This is why he recommends low-carbohydrate intake, moderate protein intake, and fat to satiety, not to a particular amount. Left to its own devices (in other words, without insulin interfering with satiety signaling), the body will set the appetite at a level of around 1000 (K)cals less than required to meet energy expenditure, the missing energy coming from fat stores.

This, of course, assumes that we have an excess of stored fat needing to be shed. As we go along in ketosis, and extra fat gets metabolised, our appetite slowly rises to the point where we are meeting all of our caloric needs from our diet. So it’s an “eat enough fat diet,” not a “cram as much fat down your gullet as you possibly can diet.”

[Skip_Cody]

it’s an “eat enough fat diet,” not a “cram as much fat down your gullet as you possibly can diet.”

So true!

[Hippie]

Fat gets converted to glucose, just like protein can. The legacy keto diet is pretty close to pure fat. However coming from someone who depends on supplements more than food, I have tendency to take a spoonful of peanut butter, then a spoonful of coconut oil. Just so my supplements don’t tear up my gut, and I’ll call that a meal.

(n=1) Part of me thinks it’s a game of keeping fat lining your gut. but that’s very unscientific.

[Shinita]

Oh this thread got resurrected (I will behave I hope, I am way less addicted to this forum than before. But I like the topic.)

I have read quite many times that the limit (using body fat for our energy need) can be very different in ketosis but it’s surely very individual too. I never had energy problems when I actually could do EF just because according to my numbers, I should have… But of course it’s individual and it matters if we are used to fasting anyway.

All diet should be “eat as little fat as possible and some less for fat-loss” for me but I was used excessive amounts on high-carb so I drastically dropped my fat intake when I changed my diet for the better. Less carbs made it possible and kind of comfortable, at least. I just miss fat sometimes but it’s not so bad now and I can do a fat fast day if I really want high-fat. For people like me, the attitude to fat should be different especially if we don’t need a ton of energy but we easily eat up a ton of delicious fat…

I need protein to satiety, fat doesn’t help without that except on fat fast days. So if my food isn’t protein rich enough, I inevitably overeat fat as I don’t accept hunger on any diet, I need to be nicely satiated on all and I always reach that indeed. Surely others have this.

Eating as much fat as possible works for some I imagine. Some people still undereat fat that way… It must be hard for some to eat much more fat than before while not being hungry due to low-carb… Some people are into lean proteins too, that may cause problems too… We can’t all just eat to satiety, whatever keto food we like and expect the macros won’t be wrong due to various things (beyond what I mentioned, hunger sign problems, too high appetite - it has almost nothing to do with hunger/satiation in my case, even compulsion, maybe habits? IDK as mine got solved by right food choices. it’s amazing how much eating right can do! but just keto couldn’t do it). Some of us need to find the right style, maybe we need to do something with our thinking…? It’s mostly the right diet and timing for me, thankfully. And good sleep. Some training. Avoiding items around me that I absolutely can’t resist but should…

moderate protein intake

I wish I could do that I have been trying since several years and I mostly fail. Definitely fail on average. Oh well, I keep trying, I am aware what I should and could do but it needs a lot of effort. It would be so easy if my body would be happy with a modest amount of protein as in the case of most people. And my younger body worked differently too, this is life I guess but so much changed in a not so long time, apparently.

the body will set the appetite at a level of around 1000 (K)cals less than required to meet energy expenditure

It’s very much not true for many of us. I can’t imagine it’s true for many, actually, it’s a HUGE energy deficit, I only have it on fat fast days when I eat 1000 kcal! (I love those days but I must skip lunch for them and that’s tricky.) But I suppose it’s for even heavier people, I only have ~50lbs to lose but still, I never had any room for deficit, I just wanted too much food on every diet. Carnivore may drastically lower my appetite quite often but my hunger remains.
In the quote, appetite means hunger, right? For us where hunger and appetite aren’t synchronized, appetite may be all over the place, I usually ignore mine, it’s typically easy. Hunger was very different, I had no chance resisting it until maybe carnivore? Now it’s different, I can and should go hungry but it’s a lovely, not annoying hunger (even better than my lovely soft fat adapted hunger that I still couldn’t resist at all). I usually don’t ignore this little hunger at lunchtime, it’s probably mental/emotional and a decades long habit too but habits are weak when I eat right. And it’s the proper hunger where we actually need food…

But maybe it means appetite… Well it doesn’t help if I am hungry… Hunger is my compass, not appetite.

It’s quite complex but humans can be like that.

[PaulL]

Fat gets converted to glucose, just like protein can. The legacy keto diet is pretty close to pure fat.

I would challenge the first sentence. Fatty acids get metabolised in the mitochondria, and conversion to glucose is nowhere in that cycle. In fact, dealing with glucose in any quantity damages a mitochondrion, so it would be unlikely that fat is converted to it under ordinary circumstances. I’m pretty sure that the glycerol backbone of triglyceride molecules can be converted into glucose, however. Is that what you are thinking of?

I would also edit the second quoted sentence to read, “The therapeutic keto diet . . . ,” The physicians who originally developed the seizure-control diet were working completely blind, reasoning from observed clinical experience, but with no real knowledge of the physiology and biochemistry involved, because those weren’t elucidated until much later.

The therapeutic keto diet was so rich in fat and so deficient in protein that it stunted the growth of a number of children when they moved into adolescence. Fortunately, more-recent research has shown that a diet lower in fat and higher in protein can have just as good a therapeutic effect.

A standard low-carbohydrate, high-fat ketogenic diet was the treatment of choice for Type I diabetics and for obese patients, beginning in the first half of the nineteenth century. To my mind, that version of the keto diet is more deserving of the term “legacy.” The therapeutic ketogenic diet for seizure control was developed later.

[kib1]

A standard low-carbohydrate, high-fat ketogenic diet was the treatment of choice for Type I diabetics and for obese patients, beginning in the first half of the nineteenth century.

Oh, you mean back when the overarching point of medicine was to cure people if at all possible?

[Hippie]

I’m pretty sure that the glycerol backbone of triglyceride molecules can be converted into glucose, however. Is that what you are thinking of?

Maybe? I’ve read, on a cellular level, maybe specially in the brain. Some functions require glucose, and it’s getting it regardless of blood sugar level. It does it with starvation conditions where the body is processing muscle. I don’t trust much of my recall anymore. fyi. But this anomaly just stands out to me.

[Shinita]

Glucose is vital for our body, actually that is part of why it’s not essential We need it even if we don’t eat anything and life often brought famine and some survived those. Some poor animals need to eat all the time, we are much more flexible and it helped our survival a lot. If sugar would be essential, we would get brain damage after a slightly longer (still very short) fast! But we don’t so our body clearly makes it from something.
Both fat and protein can be converted into glucose when in need (if glycogenic. amino acids can be glycogenic or ketogenic and that’s the extent of my knowledge…), that’s very good. But even protein doesn’t become sugar just because we eat a lot of it, only when it’s what we need. The human body working as intended is quite awesome!

[ctviggen]

Maybe? I’ve read, on a cellular level, maybe specially in the brain. Some functions require glucose, and it’s getting it regardless of blood sugar level.

I’ve never figured out exactly what requires glucose, though no matter what you eat, your body produces glucose. So something must need it.

[PaulL]

Oh, you mean back when the overarching point of medicine was to cure people if at all possible?

Shocking concept, isn’t it?

[PaulL]

though no matter what you eat, your body produces glucose. So something must need it.

The biggest need for glucose is by the red blood corpuscles. These cells must squeeze through very tight capillaries, so they don’t carry mitochondria, which take up space.

While our symbiosis with mitochondria goes right back to the first eukaryotes, our ability to metabolise glucose is even more ancient, going right back to the very first cells. So the upshot is that red blood cells feed on glucose.

This is why there always has to be some circulating glucose in the blood stream, which in turn is why there is always a certain amount of glycation of haemoglobin going on. The body evolved to handle the amount of glycation that this represents, but levels of glycation above that are what cause trouble.

Another cell type that needs glucose is spermatozoa. They cannot carry mitochondria, because if they did, their mitochondria and the ovum’s mitochondria would fight to the death and destroy one another. (Therefore, our mitochondrial DNA comes entirely from our mother, unlike nuclear DNA, which is half and half from each parent.)

As for the brain’s need for glucose, we don’t know exactly how much it requires. Cahill specified a figure of 130 g/day, based on the assumption that all the brain’s daily energy need was met by glucose. However, it is now clear that the brain will happily feed on ketones when they are available, and the mechanism by which ketones enter brain cells does not depend at all on insulin. (Paradoxically, hyperinsulinaemia prevents glucose from entering brain cells–the amount of insulin needs to be in a certain range, if it is to promote brain energy.)

For a while, Benjamin Bikman was saying that he doubted the brain needed any glucose at all, and he even issued a challenge anyone to provide proof. However, these days he seems to have backed off from that claim. It is clear from Cahill’s work (despite his estimate that everyone uses) that the brain can survive on very little glucose, providing there are sufficient ketones in the blood stream.

Georgia Ede has stated that astrocytes in the brain, those star-shaped neurons with long tendrils, don’t have mitochondria in their tendrils, so the tendrils must have glucose, but I’ve never seen a citation from her to show where she got that. It does sound plausible, however.

There are also supposedly specific cells in certain other organs that require glucose, but I’ve forgotten what they were and have no memory of where to find the reference again, sorry.

In any case, given that the amount of circulating serum glucose is about 5 mg when it’s being supplied from gluconeogenesis in the liver (and ketogenisis is supplying the rest of the needed energy, of course), it would seem that the body’s actual need for glucose is quite small.