These were the findings of a first-of-its-kind study that was conducted in Finland and published in the journal Obesity. It looked at data from nearly 2,000 randomly chosen adults between the ages of 25 and 74 to determine if their internal time clocks affected what they ate and at what time they ate.
“Earlybirds may have an extra advantage over nightowls when it comes to fighting obesity, as they are instinctively choosing to eat healthier foods earlier in the day,” Courtney Peterson of the University of Alabama at Birmingham, spokesperson for The Obesity Society, said in a news release. "Previous studies have shown that eating earlier in the day may help with weight loss and lower the risk of developing diabetes and heart disease. What this new study shows is that our biological clocks not only affect our metabolism but also what we choose to eat."
The release noted that morning types made healthier choices all day long, whereas the evening types ate less protein overall, ate more sugar in the morning and evening, and ate more fat and saturated fatty acids in the evening, than the morning types.
The study found that differences were even more pronounced on weekends, with evening types having more irregular mealtimes and eating twice as often as the morning types. They also did not sleep as well and were less physically active than the morning types.
The researchers said their work could provide insight into why people who are overweight and working to lose weight make the food choices they do throughout the day.
“Linking what and when people eat to their biological clock type provides a fresh perspective on why certain people are more likely to make unhealthy food decisions,” Mirkka Maukonen, lead author of the study, said. “This study shows that evening type people have less favorable eating habits, which may put them at a higher risk for obesity, diabetes and heart disease.”
The study used data from the national FINRISK 2007 study and was conducted out of the National Institute for Health and Welfare at the Department of Public Health Solutions in Helsinki, Finland.