It’s common wisdom that big meals and fatty foods can interfere with your sleep. However, the cause-and-effect may not be as simple as we thought. Time highlights a study published in the journal Appetite, which found that “people in different sleep categories also had distinct diet patterns”—in other words, rather than sleeping poorly because you eat fatty foods, maybe you’re eating fatty foods because you’re sleeping poorly.

Based on the 2007-08 National Health and Nutrition Examination Survey (NHANES), the study set aside four different groups of sleepers: Very short (logging in less than five hours of sleep); short (5-6 hours); normal (7-8 hours); and long (9+ hours). Each group exhibited unhealthy tendencies. Short sleepers, for example, were found to take in the most calories and ate less vitamin C, while very short sleepers drank less water and long sleepers drank more alcohol.

Whereas previous studies have looked into the ways in which sleep affects eating habits, this is one of the first to demonstrate how “diet can alter sleep as well.” It is therefore “more hypothesis-generating than confirming.” This study can lead, however, to new avenues in nutritional development like finding “the right mix of calories and nutrients to promote better sleep, which could become a low-cost strategy to curb obesity and heart disease.”

[via Time]