Nearly six in 10 were early risers — the so-called “morning larks.” These folks tend to wake up and be most active early in the day.
About 13% were “night owls.” They tended to wake up late and be most active during late afternoon or evening.
The rest — about three in 10 — fell somewhere in between (the “intermediate-type”).
Though study participants in all three groups had similar BMIs, night owls were more likely to eat big dinners and have other unhealthy habits, such as tobacco use and lack of exercise. (BMI, or body mass index, is an estimate of body fat based on height and weight.)
And all that put them at higher risk for health problems.
While 30% of morning larks had heart disease, that figure hit nearly 55% among night owls, the study found.
The risk of type 2 diabetes, meanwhile, was about 9% among morning people, and almost 37% among night owls. There was no difference between morning people and participants who were in the intermediate-type category.
Muscogiuri noted that prior studies have estimated that late risers have 1.3 times the risk of high blood pressure and high cholesterol, compared with early risers. They are also less likely to follow a heart-healthy Mediterranean diet, which is heavy on fruits, vegetables and fish.
Taken together, she said, all these features leave night owls at higher risk for heart disease and type 2 diabetes.
As to the best way to combat it, Muscogiuri suggested that efforts to get obesity under control might be more successful if sleep patterns were taken into account.
So the idea, she explained, would be to help obese patients develop better sleep-wake habits based on earlier rising, because earlier rising patterns might help such patients develop better dietary and activity habits, and thereby “increase their chance of success for weight loss.”