The deficit that burns fat also burns muscle. Separating the two is a matter of two inputs, and most advice covers only one.
A calorie deficit does not choose. It takes energy from whatever tissue is available, and lean tissue is available. That is the whole problem in one sentence, and it is why "just eat less" produces a lighter body that is not necessarily a better one.
What separates fat loss from muscle loss is not the size of the deficit. It is what you do inside it.
A widely used floor for preserving lean mass during weight loss is 1.2 grams of protein per kilogram of body weight — roughly 108 grams for someone at 198 pounds. Note the word floor. It is not a target you aim at on good days; it is the line you refuse to go under.
If you do resistance training two or three times a week, the evidence generally supports going higher — closer to 1.6 g per kilogram. Training raises how much protein you can usefully use; it does not lower the floor.
Find your protein floor Four questions, no signup. The daily number that protects lean mass, calculated from your weight. Open the calculator →Protein is the material. Resistance training is the instruction. Give your body material with no instruction and much of it goes to waste; give the instruction with no material and there is nothing to build with.
The dose required is smaller than most people assume. Two sessions a week, twenty minutes each, using bodyweight if that is what you have, is enough to change what your body does with the protein you eat. This is not about training like an athlete. It is about your body receiving evidence that the muscle is still in use.
Sometimes — and it is more likely if you are new to resistance training, returning after a break, or carrying more fat to begin with. The technical name is recomposition, and it is real, but it is slow and it is not the point.
For most people the win is holding what they have. Losing thirty pounds of fat and keeping every pound of muscle is an excellent outcome, and far more achievable than trying to gain while shrinking. Aim at keeping; treat any gain as a bonus.
Muscle and fat weigh the same per pound and occupy different volume, so a body that swapped four pounds of fat for two of muscle can read as a disappointing week. People quit on weeks like that — not because nothing worked, but because the instrument could not see it.
Two measurements can. Body composition monthly, and one strength benchmark every six weeks. Both are free, and between them they answer the only question that matters: is what is coming off the part you wanted to lose?
How much lean mass do you have? A tape measure and five questions. Your body fat percentage, your lean mass in pounds, and the protein that protects it. Open the calculator →If weight is falling and strength is falling with it, the fix is almost never a bigger deficit. In rough order of how often it is the cause:
None of this is medical advice, and your situation may have factors none of it accounts for. Bring the numbers to your clinician and ask what fits you.