In our first biochemistry class we literally learn that glycolysis

>>37228234
They don't train their body to use fat first, they literally starve their body of carbs and sugars so that their body switches to its secondary source of fuel (fat)

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>>37228234
Stored ATP and phosphocreatine are used prior to glycolytic processes taking over as primary energy sources. As far as fat being used before carbs or vice versa, that's oversimplifying how it works. Carbs will be used (via anaerobic glycolysis) when ATP is consumed at a higher rate than oxidative phosphorolation can replace it (such as sudden increases in workload). In steady state energy expenditure contexts the ATP demand over time and the available resources dictate what gets used when. The "fat burning zone" meme is based on this. At lower intensity steady state (such as sitting still and reading this) you will use basically only lipids to generate ATP (because beta oxidation->oxidative phosphorolation are more efficient than glycolysis). Higher intensity obviously requires more fuel at a faster rate, and carbs fill this role. The ratios for how much of each is being used can be measured with pretty good precision if you have access to a lab with indirect calorimetry and respiratory exchange measurement equipment. The Paleo meme basically revolves around using more fat simply by virtue of there being fewer carbs available, and the occasional use of ketone bodies as pseudo carbs (by conversion into acetyl coenzyme A, which you remember from your glycolysis lecture I hope)

Tldr Paleo is a basically a meme, keto is a dumb meme also

>>37228446

Also sorry for shit formatting, I'm on my phone between sets

>>37228446
So how is the best way to lose weight? Just less calories but with same rate of macros?

>>37228578
Best way to lose weight is to calculate your TDEE correctly (most calculators overestimate, people also overestimate their activity level) and run a 25% defecit, 30% if you're pretty fat.

>>37228446
Doesn't glycolysis generates more ATP per molecule than beta oxidation?

>>37228652
>correctly
How? I use henris benedict equation. Is this the accurate method?
What do you think about fasting? Is it true that your stomach keeps producing acid and you gonna get ulcers or just momscience?

>>37228245
Isn't fat like most cost efficient anyway?

>>37228966
I learned the opposite

>>37228918
>>37228918
>you gonna get ulcers or just momscience?
Momscience. I have small bowel adhesions. There are periods of time where I have to eat nothing so where the oinflammation site where the adhesion is at can heal. I just get fed via PICC line and TPN. Nothing occurs.

If it's at its worse, I will have a NG tibe stuck in me to make sure the stomach acid is affecting the adhesion, but it's only temp and my gastro doc prefers not to use NG tubes unless it's after some kind of surgery.

>>37228966
No. Try running a marathon and you'll see why fat is a poor energy source.

>>37228918
Katch-McCardle formula

>>37228966
Fat gives more ATP, but during the reaction it releases water instead of just CO2

>>37228979
>>37228918

Beta oxidation->oxidative phosphorolation of lipids generates much much more ATP per molecule than any glycolytic process. Depending on the length of the fatty acids you can get literally hundreds of ATP from some lipid molecules. Most you can get from a single glycogen or glucose is in the 30s. Anaerobic glycolysis you don't even net 5. Granted lipids are much larger molecules, but even accounting for this fats are much more energy dense by mass. Remember that (*on average) a gram of carb is ~4kcal, and lipid 9.

Fats are much more efficient, just slower.

>>37228979
>>37229027
>>37229070
But don't dogs have shitton more endurance than humans because they run on fat or something?

>>37228245
This. Fat is secondary fuel, when carbs are unavailable or unnecessary.

>>37229092
>>37229027

Also this anon is right, for athletic performance carb loading is uncontroversially the optimal strategy as long as it doesn't fuck you in a weigh in. Properly conditioned marathon runners can load hours worth of energy in glycogen

>>37229104
You get a lot of energy from fat, but it's not a good source. Part of marathon training is teaching your body to go from carbs to fat. After it switches to fat, you get a lot of energy, but utilizing doesn't give as good results. It's like comparing te energy output of propane vs methane vs ethanol vs methanol.

>>37228234
Oh poor guy, he must have a fast metabolism!!! :(

>>37229104
Dogs have shit endurance and they sleep half the day.

>>37229200
Dogs can be easily trained for endurance. When I started long distance running, I took my dog with me. He keeps up the entire time.

>>37228234
That's a nice bulge.

>>37229013
A friend of mine believes I'm gonna die from stomach erosion after a 3+ hours fasting. He says you must eat every 3 hours and fasting is dangerous and gives ulcers in the long run.

I only have access to biochemistry 101 books a single physiology book (engineering only school) and it doesn't address gastric acid regulation in depth, but I believe its regulated by food or the lack of food.


>>37229043
Again I have the same problem. I'm 175cm/58kg. Since I have visible abs veins I would say 12-14%BF.

Using the equation
>BMR = 370 + (21.6 * LBM in kg)
>370 + (21.6*58*(1-0.14))
>1.3*BMR
>1880

Oh shit, I've been eating 2400 kcal a day. The strange thing is that I don't feel satisfied before 2800-3000. Is this just a matter of habit or I'm fucking up the BF?

>>37229451
>175cm/58kg
Spooky.

>>37229473
Eating way over my tdee for a long time thanks to scooby's fucked up calculator. Luckly I fast here and there.

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>>37229473
This guy from /fa/ claims to be the same as me but I look way less muscular. Is he lying or I have magically dense bones?

Can you be at 15% BF and still have visible abs veins? I don't have a safe way to estimate BF since calipers sucks.