“Sleep is the most undervalued contributor to optimal health and performance,” says Dr. Keith Humphreys, professor of psychiatry at Stanford University. Dr. Humphreys does research in addiction treatment, and national mental health and drug policy. He has written for the New York Times and other publications.
Many people have no idea that getting enough sleep is essential for helping them stick to a diet, making their workouts more productive, or boosting their immune system in general.
When it comes to dieting, leptin and ghrelin are the two hormones that regulate appetite, and are adversely affected by sleep deprivation. Ghrelin, which is produced in the stomach, signals to the brain when it’s time to eat. Leptin, on the other hand, is secreted by fat tissue and has the reverse effect, signaling when you are full.
Chronic lack of sleep increases ghrelin, making you feel hungry when you don’t really need to eat, and decreases leptin, urging you to keep eating although you’ve already gotten all the calories you need.
The deep sleep state is also the time during which your body repairs itself, including your sore biceps, which benefits your workout routine.
Making a habit of sleep deprivation comes with a heavy price tag. A nine-year study of nearly 7,000 Alameda County residents, found that those who routinely slept six or fewer hours a night had a 70 percent higher risk of dying (in the same age groups) than did those who slept seven or eight hours per night.
San Francisco Gate September 2, 2007