A survey of 3,500 people, perceived from their photographs to be on average 12-14 years younger than their actual age, were more likely to take regular exercise, enjoy a vigorous sex life and have parents who are healthy and active in their old age. Some genetic factors may be implied. Also considered valuable in retaining youth are having a committed relationship (providing stability and self-assurance), avoiding stress and thinking positively, and socializing with a variety of age groups.
Researchers have long known that some animals live longer when their food supply is drastically reduced, a coping mechanism that helps them survive hard times.