>> The idea that eating fat leads to higher body fat is the most dangerously-wrong health misconception in history.
Modern equivalent of medieval leeches and enemas for "fever" (almost anything was called a 'fever' back then) and eating goat testicles for potency. Eating them raw obviously :)
Medical leeches are still very much a thing. They’re used to help improve venous circulation after plastic surgery around reattached body parts, help with burn recovery, etc
Because of homeostasis: dissolved substances like fats in the bloodstream are regulated within bands, and beyond certain limits the amount ingested doesn't translate to more: it's excreted or winds up elsewhere. Your metabolism may cause states worse than other people, sure. But that pound of butter you ingested isn't directly causing rises in the bloodstream to infinity. It's long-term accumulated burden and excess over time.
Cholesterol levels don't track intake directly. Lowering cholesterol and fat in diet needs to be done in consultation with somebody who understands your metabolism. Some vitamins are fat soluble. Some fat is beneficial.
While I always knew that sugars where the main culprit for body fat thanks to a highschool biology class, I have never understood why fat is less of a problem so thank you. Could you link me with sources or search keyword in order to know more of what the body is doing with excess fat ?
I tried "what does the body do with excess fat" and I think it covers it. For sure, you get higher triglycerides floating around in the bloodstream, and the liver is under stress. at the extreme end, its Steatorrhea which is .. unpleasant (olestra goes to the same place)
The lymphatic system is also involved.
So it's not entirely "eat as much fat as you like" by any stretch. It's more that over time, the body tends back to a baseline model. Continual high levels of fat which cause surplus in the bloodstream are heading to arterial blockage and isn't good, but the relationship of fat ingested to fats in the blood is a more complex path. "it depends"
I'm not a bio scientist or a med. Happy to be corrected.
> I've never seen anyone who's obese and having a diet that made me go "huh that's odd how can they be obese?"
Are they eating fat _or sugar?_ The body will aggressively squirrel away any unused sugar as fat. As one example, a Big Mac contains 7g of _added_ sugar. Fries? Coated in dextrose. Sugar is added to damn-near everything.
"Starch and glucose efficiently stimulate insulin secretion, and that accelerates the disposition of glucose, activating its conversion to glycogen and fat, as well as its oxidation. Fructose inhibits the stimulation of insulin by glucose, so this means that eating ordinary sugar, sucrose (a disaccharide, consisting of glucose and fructose), in place of starch, will reduce the tendency to store fat. Eating “complex carbohydrates,” rather than sugars, is a reasonable way to promote obesity. Eating starch, by increasing insulin and lowering the blood sugar, stimulates the appetite, causing a person to eat more, so the effect on fat production becomes much larger than when equal amounts of sugar and starch are eaten"
From https://raypeat.com/articles/articles/glycemia.shtml
But I suppose that plenty of fats are healthy and part of a balanced diet. And someone who eats nothing but refined sugar is more likely to be over weight that someone with a high % of fat in their diet.
No they wouldn’t stay lean. If you fed someone more calories than their body uses to maintain its current weight, they would get fat eventually. Regardless of whether they eat carbs, fat or protein.
Let's say you're being fed just the amount of calories your body needs to maintain. What influence on body fat has the distribution of carbs, protein and fat from food then?
My point was that regardless of what you eat, if you eat more than your body expends, some of the excess will be used to produce fat and you will gain weight. If you lead a sedentary lifestyle and eat 3000 calories of nothing but lean meat per day, you will gain weight.
You are right that different foods (macronutrients, more specifically) have different thermic effects and therefore require different amounts of energy to metabolise. Protein takes more energy to process than fat. This does not change my overall point.
Not much for getting lean but it's easier to overeat carbs and fats are calorie dense. That said you need to eat a mix of the three to be healthy because they all have important body functions.
You're so wrong. With only protein and fat, they would not be able to gain much weight. I've tried to gain weight on low carb/high fat, and it doesn't work. I was uncomfortably full after every meal. My tracking showed a significant calorie surplus, but my body wasn't absorbing it. Adding in more carbs made a huge difference. Hormones tell your body when to store fat.
Did you know that bodybuilders in the 1950's(before anabolic steroids) used the egg and steak diet before contests as cutting diet to get lean? They would eat, as the name suggests, large quantities of steak and eggs with butter and have a carb refeeding day every 4 days. They would get really lean on a very high-calorie diet, think 4000 to 6000 calories.
The inventor of diet famously lost a contest for being too lean.
The authors calculated that ∼18 g (79%) of the 23 g of ingested protein could be accounted for by deamination; thus those carbon skeletons were available for gluconeogenesis and release of new glucose into the circulation. The remainder, presumably, was used for new protein synthesis.
The total amount of glucose entering the circulation from all sources was calculated to be 50 g over the 8-h period. However, only 4 g (8%) could be attributed to the ingested protein.
I think you misread that experiment. It appears that some quantity of protein was converted to glucose, but that it wasn’t dependent in the quantity of protein consumed.
> Humans are bad at lipogenesis: we can only convert tiny fraction of the carbs into fat.
Because historically food is scarce or difficult to obtain, in general organisms develop mechanisms to make good use of it: when excess food ("energy") is available, it is stored rather than wasted.
This is also true in particular for mammals, and for humans. It's quite obvious that humans are very effective at storing excess energy.
It is said that sumo fighters maintain their body mass (muscle + lots of fat) by eating rice (i.e. carbohydrates) and protein.
Lipogenesis (fat generation from carbohydrates) takes place mostly in the liver.
"Excess acetyl CoA generated from excess glucose or carbohydrate ingestion can be used for fatty acid synthesis or lipogenesis."
Nope. If humans eat both carbs and fat (most of us do), the excess calories of fat goes mainly into the storage (or plaques to your arteries), while the carbs are used in the sort term (converted into glucose).
> Lipogenesis is mostly derived from carbohydrates and is a relatively minor contributor to whole-body lipid stores, contributing 1–3% of the total fat balance in humans consuming a typical diet.
Ketosis is probably our rudimentary "wintersleep mode". Rudimentary as we are basically tropical animals (look at our lack of fur).
We should not eat for ketosis. But we can eat (restricted to fat and protein) and still stay in ketosis, which is marketed as the keto diet and is not well tested in long term studies. You are a guinea pig when you do this long term.
"Being fat" and having too much fat (or the wrong kind of fat) in the blood or brain are not equivalent. Eg people with high cholesterol can be quite slim also.
Your body can't take fat from plants and animals and directly embed it into fat calls. The metabolism of ingested fat takes much more steps than say sugar, which can be directly absorbed into fat cells and also raises insulin resistance. Sugar and refined carbohydrates are a far bigger reason for obesity than fat consumption or "greasy food".
People get fat through consuming more calories than they burn for energy during the day. There are extra but around the edges but no matter the ratio of fat to carbs to protein, if someone consumes (food or liquid) 3,000 calories a day but only burns 2,500 calories a day then a decent portion of that 500 cal difference will get stored as body fat. You could eat 0 calories of fat but if that total of carbs and protein is over your energy burn then over time you will add body fat.
I believe most people gain excess body fat through eating a little bit more than they need each day and then two or three weeks a year they eat and drink much more (holiday, Xmas, birthday etc), rather than consuming vast amounts of food day in day out of the wrong macro nutrient make up.
The calorie hypothesis isn't the most likely from all the research I've done. The calorie as a unit of measure doesn't even make much sense IMO.
A calorie is measured by burning food a specific distance away from a specific amount of water and measuring how much the water temperature rises. It's based on an assumption that the body uses all energy in the food the same, and that fire is analogous to the complex process from digestion to energy use in the cell. The calorie as a measure effectively equates the body to a coal power plant.
Anyone who tracks their calories daily for a long period of time will see that when they eat more they gain weight, when they eat less they loose weight.
Like I said above, there are other aspects that can factor but “calories in calories out” accounts for 80% of weight loss and weight gain (applying the broad brush of the 80:20 rule)
If a calorie is a calorie, would you agree that I would be just as well of eating 1800 calories of fat rather than a balanced diet? Could I stick to 1800 calories of gasoline?
We can't simply burn food and deem that an accurate analog to how the body processes and utilizes different food. Ask anyone that live(d) primarily on rabbit meat.
And to be clear, the 80:20 rule is am extremely broad and inaccurate rule of thumb that isn't useful when applied to something specific. You can't claim that calories in equals 80% of calories out because Paredo.
But it does depend on the type of foods. For example, let's take a serving of almonds listed at 160 calories. Your body may only absorb 120 (depends on the person) of those calories to be burned due to the fiber in the almonds. While foods with sugar and little fiber, you get close to 100% of the listed calories.
Sure, and that kind of thing falls into the 20% of the 80:20 rule of most things. The vast majority of people loose or gain weight based on their calorie in take / expenditure
There are exceptions, I have the APOE 4/4 variant gene which results in my metabolism not dealing with saturated fat as well, and eating saturated fat does end up raising my bad cholesterol among a bunch of other terrible side effects
perhaps not coincidentally, this variant also comes with a higher risk of Alzheimer's disease
We've probably done more harm with the similar, and also incorrect, assumption that eating more saturated fats go directly to the blood and clog arteries.
Can you point to some evidence that increased saturated fat consumption does not increase LDL? Or that there is no link between serum LDL levels and plaque build up? Or are you making a different claim?
Dr Michael Eades is a good gateway toif you're interested. He wrote a book a while ago now titled Protein Power [1], I think he is working on an update/sequel as well.
At the high level, my basic claim is that the idea that dietary saturated fat directly leads to heart attack is incorrect. The history of this claim dates back to President Eisenhower. After having a heart attack while in office he wanted to tell the public how he could avoid the same fate. Researchers cut corners to meet political targets, ignoring data that disproved their hypothesis and claimed that plaque found in cadaver arteries was made of saturated fats and that it got there due to the person's diet.
The claims weren't backed up by the studies used and we were told that this was now a known fact when it wasn't. We've spent many decades since avoiding saturated fats in favor of unsaturated fats, which are highly oxidative and have concerning side effects when run through the Krebs Cycle.
Dr Eades also has a few interesting talks on the subject when he walks through the Krebs Cycle and the difference of saturated and unsaturated fats in case that's helpful. I think [2] is one I watch years ago, though he has other similar talks on YouTube as well.
Per the Nature paper, this fat is believed to be part of an immune system response and not related to your intake or total body fat. It is also far from clear that eliminating the production or use of this fat during a microbe invasion would lead to more or less dementia down the road (a good reminder that clinical trials are useful and also risky). This work shows a very refreshing and solid hypothesis and lots of people work on it, but it’s not reason to start changing diets.
Yeah, I almost wish I hadn’t asked given the comments. Really points at an interesting mechanism though. Hopefully this means some kind of preventative or even treatment is possible.
More likely we'll need to start paying attention to sugar intake. I've heard researchers call Alzheimer as "type 3 diabetes". This makes total sense to me since sugar consumption is a big driver of body fat accumalation.