Sleep affects metabolic health: studies found reduced insulin sensitivity after healthy volunteers slept four or five hours for several nights.
Why sleep matters
Short sleep raises stress hormones and hunger, reduces fullness and insulin sensitivity, and may increase next-day cravings.
A short fix list
Keep a steady wake time, get morning daylight, stop caffeine by mid-afternoon, eat 2 to 3 hours before bed and dim lights in the final hour.
When it is more than habits
Snoring, gasping or unrefreshing sleep may signal sleep apnoea, common with neck or waist weight. Treatment may help glucose and blood pressure.
Education, not personal medical advice. Consult a qualified clinician about diagnosis, treatment and your results.