Sleep and weight loss, the most overlooked lever

Poor sleep makes you hungry

Ghrelin sends the hunger signal, leptin the fullness signal. In a 2004 study of 12 young men, published in the Annals of Internal Medicine, 2 nights limited to 4 hours raised ghrelin by 28% and lowered leptin by 18%. Participants were 24% hungrier, especially for sweet and fatty foods.

A review of 11 studies published in 2017 in the European Journal of Clinical Nutrition puts the gap at 385 calories a day. Over a week with 3 or 4 nights that are too short, it goes past 1,000 calories.

Sleep and weight loss, fat or muscle

In a 2010 study of 10 overweight adults, people followed the same diet twice, for 2 weeks each time. Once with 8.5 hours in bed, once with 5.5 hours. With the short nights, they lost 55% less fat, and more muscle. Losing muscle means using less energy at rest, and it paves the way for yo-yo dieting.

How many hours of sleep to lose weight?

The NHS page on insomnia says adults need 7 to 9 hours on average. In a 2022 study in JAMA Internal Medicine, overweight adults who slept less than 6.5 hours extended their nights by about 70 minutes. They then ate 270 fewer calories a day.

5 habits for better sleep

These habits follow the NHS Every Mind Matters advice on how to fall asleep faster and sleep better.

• A regular routine. Go to bed and get up at similar times, even on days off.
• A lighter evening meal. Large meals close to bedtime can make it harder to fall asleep. Our ideas on what to eat in the evening go in this direction.
• Caffeine earlier in the day. Tea, coffee and some soft drinks contain caffeine. The NHS suggests none for at least 6 hours before bed.
• Alcohol kept away from bedtime. It disrupts sleep, so avoid it 1 to 2 hours before bed.
• Screens off 1 hour before bed. Keep the bedroom dark and quiet, and read or listen to calm music instead.

Start with a fixed bedtime, 5 nights out of 7. If you eat well and have hit a weight loss plateau, look at your nights first. If sleep problems last, with loud snoring and daytime tiredness, talk to your GP. This article does not replace advice from your GP or another health professional.

At Witney Nutrition Club

Witney Nutrition Club is open from 6:30am to 11am on weekdays, and members who have breakfast there before work often find it anchors a regular morning routine. The free assessment looks at your meals, your timings and your nights together.