Researchers in Japan have found that laughing during dinnertime results in a smaller rise in postmeal blood sugar, compared with not laughing. As reported in Diabetes Care (May 2003), the researchers measured blood glucose levels of 19 type 2 diabetics and 5 nondiabetics. They all ate the same meal on 2 separate days. On day 1, they listened to a boring 40-minute lecture. On day 2, they watched a Japanese comedy show. Postmeal glucose levels were higher after the lecture and lower after the show in both diabetics and nondiabetics.
The researchers suggested that laughter could increase energy consumption by working the abdominal muscles. Or it might affect the neuro-endocrine system, which controls glucose levels in the blood. In any event, as 1 researcher said, "We should laugh more."