Start with the arithmetic, because the answer to the practical question is usually a number and the number is usually achievable.
Absolute strength holds up better than scale weight during a deficit for a straightforward reason: strength is substantially neural and skill-based, and the contractile tissue you retain is being trained harder relative to its size. Grip strength and repetition maxima are therefore lagging indicators of muscle loss rather than leading ones, which is an argument for measuring both.
Specifically, the first four weeks of loss is substantially fluid and glycogen. Each gram of stored glycogen carries roughly three grams of water, and total glycogen is on the order of 400 to 500 g, so the obligatory water shift alone accounts for a couple of kilograms. This is why the first month looks dramatic and the second looks like a plateau when in fact the fat-loss rate has not changed.
Adaptive thermogenesis — a fall in energy expenditure beyond that predicted by the change in body composition — is documented across weight-loss interventions and is the mechanistic basis for the plateau being expected rather than anomalous.
I would be careful with the supplement literature here; effect sizes are small, the studies are mostly in trained young men, and generalisation to a large deficit is not obviously valid.
The plateau is arithmetic. Treat it as arithmetic and the response follows.
edited 22 Nov 2024 by v_ramaswamy — expanded the table to cover the lower concentration
3Two of us worked through this independently and arrived here, so it is at least reproducible. – e_dziedzic 5 months ago 2Worth adding that the method section is where the answer usually is. – Dr_Jonas_Halvorsen 4 months ago add a comment