The Food-Sleep Connection

Why we crave junk food when we’re tired

- Anahad O'Connor

MUCH OF WHAT we know about sleep and diet comes from large epidemiological studies that have found that people who suffer from consistently bad sleep tend to have poorer quality diets: less protein, fewer fruits and vegetables and more added sugar. But these studies can show only correlations, not cause and effect. They cannot explain, for example, whether poor diet leads to poor sleep, or the reverse.

Marie-Pierre St-Onge, an associate professor of nutritional medicine at New York’s Columbia University Irving Medical Center and the director of its Sleep Center of Excellence, studies the relationship between diet and sleep. Her work suggests that it is better to focus on the overall quality of your diet. In one randomized clinical trial, published in the Journal of Clinical Sleep Medicine in 2016, she and her colleagues recruited 26 healthy adults and controlled what they ate for four days while monitoring how they slept. They discovered that eating more saturated fat and less fibre from foods like vegetables, fruits and whole grains led to reductions in slow-wave sleep, which is the deep, restorative kind.