The exact same three-meal structure can be adjusted meaningfully just by shifting portion emphasis, depending on whether a member's actual goal is fat loss, muscle gain, or general maintenance.
Fat loss: protein and vegetables first
Building each meal around a protein source and vegetables, with a smaller portion of starch, tends to support satiety within a calorie deficit.
Muscle gain: consistent protein plus enough total volume
The same protein-first structure applies, but with larger overall portions and denser carbohydrate sources to support the surplus needed for growth.