A recent study reports that People who are ‘night owls’ could have a greater risk of type 2 diabetes and heart disease than those who are ‘early birds’. Because wake/sleep cycles cause metabolic differences and alter our body’s preference for energy sources.
For the study, published in the journal Experimental Physiology, the team classified participants into two groups (early and late) based on their ‘chronotype’ — our natural propensity to seek activity and sleep at different times. They used advanced imaging to assess body mass and body composition, insulin sensitivity and breath samples to measure fat and carbohydrate metabolism.
To study fuel preference, they were tested while at rest before completing two 15-minute bouts of exercise: one moderate and one high-intensity session on a treadmill. Researchers found that early birds use more fat for energy at both rest and during exercise than night owls. Early birds were also more insulin sensitive. Night owls, on the other hand, are insulin resistant, meaning their bodies require more insulin to lower blood glucose levels, and their bodies favoured carbohydrates as an energy source over fats.