Intermittent fasting compresses your eating into a shorter daily window (commonly 16:8, 18:6, or one-meal-a-day approaches), which can make hitting a training-level protein target (see our protein needs guide) feel logistically harder — it isn't impossible, but it does require more deliberate meal construction than spreading the same total across 5-6 meals would.
Does the "spread it out" research still apply?
Our protein timing guide covers evidence that spreading protein across 3-4 meals a day slightly outperforms concentrating it into one or two, for muscle protein synthesis specifically. Most of that underlying research wasn't designed around fasting protocols, so it's worth holding loosely — total daily protein appears to matter considerably more than exact distribution, and most intermittent fasting research on muscle and body composition outcomes hasn't found a clear disadvantage versus traditional meal spacing, provided total protein and total calories are matched.
Practical strategy for a 16:8 window
Two to three larger, protein-forward meals within the window is the realistic approach for most people: a large first meal built around a complete animal or combined plant protein (30-40g), a mid-window meal of similar size, and a protein-dense final meal or shake before the window closes — this spreads intake into 2-3 large doses instead of 1, without requiring the 5-6 small meals a full-day spread approach would need.
Where a shake earns its keep
A protein shake is genuinely useful in a compressed eating window specifically because it lets you add 25-40g of protein to any of your 2-3 meals without adding much volume or prep time — useful if your window is tight enough that cooking multiple full protein-forward meals feels impractical.
Practical takeaway
Total daily protein is the priority; getting there in 2-3 large, deliberately protein-forward meals within your window works about as well as the traditional 5-6 meal spread for most people's actual goals.