Anyone who has ever suffered in bed after eating three slices of pizza could surmise there is some relationship between food and sleep quality. For Marie-Pierre St-Onge, the director of Columbia University’s Center of Excellence for Sleep and Circadian Research, years of studying the relationship confirmed it. Data from large-scale population studies showed that eating a lot of saturated fat and simple carbohydrates made it harder to get deep, restorative sleep, she said.