Sleep and Weight Loss

Your scale is stuck? Look at your sleep first.

Ghrelin goes up

One bad night raises hunger hormone by ~15%.

Leptin goes down

The 'I'm full' signal drops ~15% on 4 hours of sleep.

Cravings shift

Sleep-deprived brains crave 300+ extra calories, mostly carbs and fat.

Insulin resistance

One week of 5-hour nights = insulin sensitivity of a prediabetic.

Cortisol stays high

Evening cortisol drives belly fat storage and blocks recovery.

Muscle vs fat loss

On low sleep, 70% of weight lost is lean mass — not fat.

Read the full guide

Evidence, tables and a 12-item checklist on our blog.