Calorie Deficit: How Big Should It Be to Lose Fat Safely?

The short answer: 300–500 kcal/day works for most. It’s large enough to see progress, small enough to sustain.

Signs your deficit is too big

• Constant fatigue or irritability
• Poor workout recovery
• Binge‑restrict cycles

Signs your deficit is too small

• No change in weight trend over 2–3 weeks
• Strength and energy fine but goals not moving

Make data‑driven tweaks

Change by 100–150 kcal at a time and reassess after 10–14 days.

Summary

The “best” deficit is the one you can repeat daily without burning out.