The activity patterns and sleep cycles of an individual could influence his risk of diseases, such as type 2 diabetes and heart disease.

This could be attributed to wake/sleep cycles that cause metabolic differences and alter body's preference for energy sources.

The researchers found that those who stay up later have a reduced ability to use fat for energy, meaning fats may build-up in the body and increase risk for type 2 diabetes and cardiovascular disease.

The metabolic differences relate to how well each group can use insulin to promote glucose uptake by the cells for storage and energy use.

This group's impaired ability to respond to insulin to promote fuel use can be harmful as it indicates a greater risk of type 2 diabetes and/or heart disease.

The cause for this shift in metabolic preference between early birds and night owls is yet unknown and needs further investigation.

This observation advances our understanding of how our body's circadian rhythms impact our health. Because chronotype appears to impact our metabolism and hormone action

we suggest that chronotype could be used as a factor to predict an individual's disease risk."