Having more body fat and less muscle as we age leads to less flexible thinking, possibly due to immune system changes. People with a higher BMI have more immune system activity, which affect cognition.

People who used artificial sweeteners were more likely to gain weight over a 7-year period, perhaps due to alteration in gut bacteria or propensity to overcompensate with calories later on.

Exercising daily at moderate intensity for 30 minutes was linked to higher levels of GLP-1 in men, a hormone that reduces appetite and blood sugar, thus lowering risk of diabetes.

Sleeping for over 9 hours per night or taking regular naps longer than 90 minutes was linked to a 25% increase in risk of stroke compared to nappers of 30 minutes or less.