Fitness more critical than weight
   Weight may be less important in longevity than fitness, according to research from the Cooper Institute for Aerobics Research in Dallas. The study followed 21,856 men, age 30 to 83 at baseline, for 8.1 years. During that time there were 427 deaths adjusted for age, smoking, and alcohol intake.
   The authors found that the health benefits of normal weight (BMI of 19-25) are limited to men who have moderate or high levels of cardiorespiratory fitness. Unfit men in the same weight range were not protected. They had 2.3 times the risk of all-cause mortality, compared with fit men in this group. At the next weight level, unfit men with a BMI of 25 to 27.8 also had a agreater risk of all-cause mortality than fit men in the same group. Fit but overweight men with a BMI of 27.8 or more had a smilar rate of all-cause mortality as physically fit men of normal weight.
   Current weight guidelines in the United States, which recommend healthy weight as a body mass index from 19 to 25 may be misleading, unless cardiorespiratory fitness also is considered, the researchers conclude. They suggest that working to increase fitness may be more important than maintaining lower weight. (Healthy Weight Journal 1999:13:3;34 / Lee CD, Jackson AS, Blair SN. U.S. weight guidelines: Is it also important to consider cardiorespiratory fitness? Int J Obes 1998:22[Suppl2];2-7)

Fidgeting: every little bit counts
   The "fidget factor" and gender made the difference in who gained more weight for 12 men and 4 women who overfed themselves, 1,000 extra calories a day for 8 weeks. Average weight gain was about 10 pounds for the young adults in the study. Some gained as little as 3 pounds and others up to 16 pounds.
   On the average, about 56 percent of the excess calories were "wasted," (i.e., they were not stored either as fat or fat-free mass). The calories were dissipated in three ways: by increases in resting energy expenditure, thermic effect of food, and in nonexercise acitivity thermogenesis. The latter accounted for about two thirds of the calories, in small frequent movements, not big movements such as walking or climbing stairs. Those who "wasted" the most calories and gained the least weight stood up more often, stretched, fidgeted, were more restless, moved more in their daily activities. Exercise levels and the thermic efficiency of exercise were unchanged.
   However, there was a great deal of variation between individuals. The four women had the smallest increases in nonexercise activity thermogenesis and tended to gain more weight. The researchers concluded that as people overeat, some can effectively dissipate the excess energy so that it is not stored as fat, while others will have greater fat gain and be predisposed to obesity. (Healthy Weight Journal 1999:13:3;35 / Levine JA, Eberhardt NL, Jensen MD. Role of nonexercise activity thermogenesis in resistance to fat gain in humans. Science 1999:283;212-214)