Night owls may gain more belly fat, study reveals

Individuals who tend to stay up late may be more prone to accumulating belly fat, even if their overall daily calorie consumption is similar to that of early risers. A recent study conducted in New Zealand suggests that a person's sleep schedule could influence where fat is stored in the body.

The research, led by a team at Massey University, analyzed the sleep habits, dietary records, and health data of 287 women aged 18 to 45. Participants were categorized based on their chronotypes: morning, intermediate, or evening. The study found that evening types consumed less breakfast and concentrated more of their calorie intake later in the day. Their diets also tended to be of lower quality, with less fiber and fewer essential vitamins and minerals.

Using dual-energy X-ray absorptiometry (DXA), researchers assessed body composition. They discovered that evening types not only had higher body mass indexes (BMI) but also a significantly greater proportion of abdominal fat compared to morning and intermediate types. This indicates a tendency for fat to accumulate more around the waist.

Further analysis of blood samples revealed that night owls had higher levels of insulin, triglycerides, and leptin. Conversely, their levels of high-density lipoprotein cholesterol (HDL), which helps protect cardiovascular health, were lower. Overall, their metabolic health indicators were poorer than those of early risers. The study, published in 'Frontiers in Nutrition,' highlights the role of meal timing in regulating the body's internal clock and its potential impact on metabolic health.