1: Am J Clin Nutr. 1999 Mar;69(3):373-80
BACKGROUND: Cardio respiratory fitness and body fatness are both related to health, but their interrelation to all-cause and cardiovascular disease (CVD) mortality is unknown. OBJECTIVE: We examined the health benefits of leanness and the hazards of obesity while simultaneously considering cardio respiratory fitness. DESIGN: This was an observational cohort study. We followed 21,925 men, aged 30-83 years, who had a body-composition assessment and a maximal treadmill exercise test. There were 428 deaths (144 from CVD, 143 from cancer, and 141 from other causes) in an average of 8 years of follow-up (176,742 man-years). RESULTS: After adjustment for age, examination year, cigarette smoking, alcohol intake, and parental history of ischemic heart disease, unfit (low cardio respiratory fitness as determined by maximal exercise testing), lean men had double the risk of all-cause mortality of fit, lean men (relative risk: 2.07; 95% CI: 1.16, 3.69; P = 0.01). Unfit, lean men also had a higher risk of all-cause and CVD mortality than did men who were fit and obese. We observed similar results for fat and fat-free mass in relation to mortality. Unfit men had a higher risk of all-cause and CVD mortality than did fit men in all fat and fat-free categories. Similarly, unfit men with low waist girths (<87 cm) had greater risk of all-cause mortality than did fit men with high waist girths (> or = 99cm). CONCLUSIONS: The health benefits of leanness are limited to fit men, and being fit may reduce the hazards of obesity.
Lee CD, Blair SN, Jackson AS.
Division of Epidemiology & Clinical Applications, Cooper Institute for Aerobics Research
Dallas, TX, USA