Protein is the nutrient most worth paying attention to if you lift. It supplies the building blocks for muscle repair and growth, helps preserve muscle when you are eating less, and tends to keep you fuller than the same calories from other sources.
It is also surrounded by more noise than almost any other topic. The useful part is short.
How much
For people who resistance train, the commonly supported range is about 1.6–2.2 g per kilogram of bodyweight per day. Above roughly 1.6 g/kg the additional benefit for muscle becomes small for most people, and the upper end is most worth aiming at in a calorie deficit.
At 150 lb (68 kg), that is roughly 110–150 g a day. At 200 lb (91 kg), roughly 145–200 g. If you carry a lot of body fat, using your goal weight gives a more realistic number. If you have kidney disease, or are pregnant, set your target with your doctor or a registered dietitian.
When
The daily total does most of the work. Spreading it across three or four meals, each with a reasonable serving of protein, is marginally better than eating it all at once and tends to be easier anyway.
Having a meal containing protein within a few hours either side of training is sensible, but there is no narrow window after a session that you need to race to meet. Protein before bed is fine if it suits you, not something you need to add.
From where
Meat, fish, eggs, dairy, tofu, tempeh, legumes and protein powders all count. Animal proteins and soy tend to be more complete per serving, and many other plant proteins are lower in one or more essential amino acids.
That does not make plant-based eating a problem for training. Eating a variety of plant proteins over the day, and aiming toward the upper part of the range, covers most of the difference. Powder, plant or dairy, is just a convenient form of the same thing.
What to do this week
Work out your range, then check what you actually eat on two ordinary days. If you are short, the easiest fix is usually adding a protein source to the meal that currently has the least, often breakfast, rather than adding a shake on top of everything.
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