2.4 The importance of sleep

Sleep is one of the six pillars of lifestyle medicine – a list that also includes exercise, nutritious eating, stress reduction, social connection and avoiding risky substances.

People regularly sleeping for less than six hours a night are more likely to be overweight or obese compared with those sleeping for longer. Sleep has specific effects on the appetite-regulating hormones leptin (creates a feeling of fullness so decreases appetite) and ghrelin (increases appetite) that contribute to weight gain.

Typically, leptin levels rise during sleep. Insufficient sleep is associated with higher levels of ghrelin and lower levels of leptin, and this not only makes someone feel hungry but also seems to induce cravings for energy-dense foods. Any kind of sleep disruption increases ghrelin levels, leading to feeling hungry.

Asking about sleep and advising on sleeping well is therefore an important part of weight management. Evidence-based sleep apps are available free on the NHS in many areas: Sleepio (cognitive behavioural therapy [CBT] for insomnia) and Pzizz (for calming a racing mind).