PCOS Calorie Deficit: How Big Should It Be?

The Right Deficit for PCOS

If you have polycystic ovary syndrome, the size of your calorie deficit matters more than you might think. The 2018 International Evidence-Based Guideline for PCOS — endorsed by the Endocrine Society — is clear: lifestyle change, not very low-calorie diets, is first-line. Crash diets tend to worsen lean-mass loss and are hard to sustain, which is exactly the wrong approach when insulin resistance already makes fat loss stubborn.

A practical starting point is a modest deficit of about 250–500 kcal/day below your maintenance needs — roughly 0.5–1 lb per week. That pace preserves muscle, protects adherence, and still improves insulin sensitivity.

Why Gentle Wins

• Steeper deficits raise hunger and cortisol, increasing relapse risk.
• Losing 5–10% of body weight improves ovulation, menstrual regularity, and insulin sensitivity in many people with PCOS — you do not need a dramatic deficit to see benefits.
• Pair the deficit with higher protein (1.6–2.0 g/kg) to hold onto lean mass.

Use our PCOS Calorie Calculator to get a PCOS-adjusted maintenance estimate, then subtract a gentle deficit. For the full picture, see our PCOS hub, the PCOS weight-loss diet, and PCOS protein intake.

This article is educational. Work with a registered dietitian or endocrinologist, especially if you take metformin, have prediabetes, or are trying to conceive.