Americans hear four good health rules: don't smoke, maintain a normal weight, eat fruit and vegetables, and get some exercise. But almost nobody follows them.

A study of national data has shown that only 3% of Americans followed all four of the recommended rules. Women, older people, white people, better educated people, people in good health, and wealthier people did a little bit better in following the rules. Younger people were slightly better at maintaining a body mass index of 25 or less (Archives …