Setting a Calorie Target for Weight Loss Without Losing Muscle
A moderate deficit of roughly 15–25% below TDEE (commonly around 500 calories/day for many people) tends to preserve more muscle than a steep deficit, especially when combined with adequate protein intake (roughly 0.7–1 gram per pound of body weight) and resistance training — an overly aggressive deficit increases the share of weight lost that comes from muscle rather than fat.
"Eat less, lose weight" is technically true but incomplete — the size of the deficit and what happens alongside it determine how much of that weight loss is fat versus muscle, which matters for both appearance and long-term metabolic health.
Why a very large deficit backfires
A steep calorie deficit (well below 500 calories/day, or a large percentage of TDEE) forces the body to draw on both fat and muscle tissue for energy more aggressively than a moderate deficit does, since a smaller, more gradual gap gives the body more room to prioritize fat stores. Rapid weight loss numbers on the scale can look appealing, but a meaningful share of that loss in an aggressive deficit is often lean tissue, not fat.
The role of protein and resistance training
Adequate protein intake — commonly cited around 0.7 to 1 gram per pound of body weight during a deficit — gives the body the building blocks to preserve muscle even while overall calories are reduced. Resistance training sends a signal to retain muscle tissue as a metabolically active priority, rather than treating it as available energy to burn alongside fat.
A practical target
For most people, a deficit of roughly 500 calories a day below TDEE — producing about 1 pound (0.45 kg) of weight loss per week — is a commonly used, sustainable starting point that balances noticeable progress against muscle preservation and long-term adherence.