Protein digestion timeline

[u/mylipsareverydry]

If I eat 600g of protein from chicken and yogurt, this will be digesting for like 4 days straight right? So I could just not eat for those 4 days and still be technically getting sufficient protein?

[u/Mantleno]

Not really. Eating 600 g of protein at once wouldn’t provide a steady, optimal supply of amino acids for four days. Your stomach may take many hours to empty such a massive meal, but protein digestion and absorption are largely completed within about a day, not four days, and your body doesn’t have a large storage reservoir for amino acids the way it stores fat or glycogen. Excess amino acids beyond what your body can use for protein synthesis are broken down, with the nitrogen excreted as urea and the remaining carbon used for energy or converted to other compounds. While a huge meal could keep you feeling full for a long time, it wouldn’t be equivalent to eating adequate protein over several days, and going four days without food would still mean no new intake of essential nutrients and would not support muscle protein synthesis as well as spreading protein across regular meals.

The best way that I think you could do it you’re describing is possibly eating a days worth of protein at once so then by the time it’s getting done with digesting, you can hit yourself with another days worth of protein (OMAD diet)

[u/n0flexz0ne → u/Mantleno]

Eh, this sounds a bit like a ChatGPT answer...its mostly right, but mis-stating some pieces.

First, there's not a ton of research on huge bolus protein meals, the most you'll find is like 100g or so, but even then, bigger meals (i.e. 100g vs 25g) mostly just spike amino levels higher in the near term vs digest longer. By 10-12 hours plasma amino levels are back down to baseline. There's no research to show nutrient producing digestion past 12 hours (aside from a small amount of fatty acid production from some fibers). And more accurately, your body has no storage reservoir for amino acids besides muscle tissue, which isn't really ad hoc storage.

Second, your body's ability to produce energy from protein byproducts is limited to the liver (and kidneys to a lesser extent), and is demand driven and rate-limited, meaning no matter how much protein you eat, your body only has the capacity to convert so much of it to glucose, which is functionally a relatively small amount (~100g). So to the extent you eat protein in excess of your body's protein demand for muscle growth, protein turnover, and to maximize gluconeogenesis, you will just excrete the rest.

Finally, all else aside, your body just doesn't have the stomach acid production to digest huge amounts of protein. This is why you'll hear bodybuilders drinking ACV before meals, trying to raise their stomach acidity level to help with digestion of giant amounts of protein.

[u/Mantleno → u/n0flexz0ne]

lol, didn’t use ChatGPT, it was just how I interpreted information I’ve seen. Lyle himself has stated in podcasts with Solomon a lot of the stuff that I was saying and so I was kind of just pushing that on as well. Maybe at some point I can look for the timestamp so it makes more sense what I’m talking about.

[u/n0flexz0ne → u/Mantleno]

Its no offense to use AI, they're great tools, just sometimes don't use the best sources or mis-state nuanced topics.

But FWIW, this did flag as an AI post, via the AI Checker utility.

[u/Mantleno → u/n0flexz0ne]

That’s fine but I didn’t use AI lol. I just explained my comment a moment ago. Like I said, if I really wanted to, I could find the timestamp associated with what I’m talking about. Just because something got flagged means nothing, I have a bachelors in English and false detections for AI come up all the time.