I am wondering if someone could explain the way the body uses protein when it comes to different bodily needs. If one eats exclusively protein, will their body prioritise the use of protein for energy rather than muscle protein synthesis? If one eats a fairly significant calorie deficit, whilst consuming all three macros, will their body still prioritise dietary protein for energy rather than using it to repair tissue? If the first food consumed after a fasted state is protein majority, and that person is aiming to build muscle after working out, will some or much of that ingested protein be used on restoring energy rather than building muscle because fats and carbs are not present in sufficient amounts?
Thanks very much
you cant use protein for energy directly. youll just overeat protein, your body will store it as bodyfat, then youll assumedly be in a ketogenic state and your body will break down the bodyfat to use as energy.
There is a lot going on here. I’m sure I’m going to get things wrong but since I’m first at the party or maybe second by now someone can correct me and maybe have to explain less. First thing. Eating strictly protein I believe your body turns excess protein into a glucose (in simplest terms) gluconeogenesis. So technically you’re not using “protein” as an energy source.
I think if you are eating all macros with a significant calorie deficit your body will go after the easiest thing to consume first which I believe to be carbohydrates. Then let’s say you are sprinting it will dig into muscle for energy. If a person is just running a calorie deficit all the time their metabolism just slows down.
The next statement is a very controversial statement I’m going to make. The food after workout doesn’t matter as much as some people make it out to be. Seeing as you’re JUST asking about protein after workouts for “repair”. If you’re worried about when it does matter I would recommend you look into insulin and it’s task in our bodies when it comes to fat storage and nutrient delivery. Otherwise, I would argue that research now would point to the most important thing would be to hit your macros. Some people argue the fact that daily calorie don’t matter and that weekly ones should be watched more.
Edit: spelling
Ultramarathoners gain calf muscle although all humans are in large caloric deficits while running. I’d say practice fasting, to get a feeling for the rest. It’s good to have a feeling for it. People vary. Generally, though, the body seems to do smart things. Recovering from extremely long fasts takes a few days, but a few hours and maybe a nap gets you most of the way there. On the last bit, though - don’t underestimate our storage.
And the body is regulating this stuff; when you’re starving, you’re increasing your insulin sensitivity and growth hormone. So just doing what feels right will work fine. If the body makes a mistake it can always just eat itself again.
It sounds like what you’re talking about is the functional separation between functional calories i.e. protein, and fuel calories I.e. carbs and fats.
It is possible to be in a caloric deficit and lose body fat without losing lean mass by managing your overall fuel intake and maintaining a consistent intake of protein.
Overall calories don’t really matter. It’s the actual quantities of macronutrients that matter. You can overeat or under eat any macronutrient. Calories don’t make you fat. Excess amino acids, fatty acids, or glycogen that your body can’t use does.
If you want to build muscle. The three biggest factors are 1. Protein intake 2. Muscle stimulus 3. Sleep and recovery.
Your body will always prioritize glucose (sugar, carbs) for energy, before anything else (unless you drink alcohol). The next in line is body fat, Aka the ketogenic state; however, it’s so easy to pull yourself out of a ketogenic state because again, your body will use glucose for energy if it’s available. Your body does convert nutrients into glucose other than sugar, which is a whole complicated topic
With that said, some of those proteins are going to be converted into glucose
As far as whether protein will still be used to repair tissue - protein does a lot, as you said it repairs tissue, but there are other things besides that that utilize protein. It will go to your skin, hair, your joints.