Diet and calorie restriction.

Current data suggest that the life spans of commonly held rodent species have decreased and the occurrence of tumors occurs earlier in the lifespan of ad libitum-fed animals. The most likely cause of this change in the life span of barrier-reared genetically defined animals is increased body weight. The effects of caloric restriction on a variety of functional measures and on age-dependent tumors and lesions are the focus of this presentation. Recommendations for caloric restriction, or at least "dietary control," will be discussed.