The Alameda County Study is a probability study of residents from Alameda County, California which examines the relationship between lifestyle and health.  The "1965 cohort" were given health questionaries in 1965, 1973, 1985, 1988, 1994, and 1999. In their examination of the collected data, D. Wingard and colleagues found that those who followed five practices lived healthier and longer lives:
- Avoiding smoking.
- Exercising regularly.
- Maintaining a healthy body weight.
- Sleeping seven to eight hours per night. (For related research, see Sleep#Optimal.)
- Limiting consumption of alcoholic drinks.
Later studies considered the impact of religiosity, social status, and hearing loss on health outcomes.