TY - JOUR
T1 - Weight loss increases and fat loss decreases all-cause mortality rate
T2 - Results from two independent cohort studies
AU - Allison, D. B.
AU - Zannolli, R.
AU - Faith, M. S.
AU - Heo, M.
AU - Pictrobelli, A.
AU - Vanitallie, T. B.
AU - Pi-Sunyer, F. X.
AU - Heymsfield, S. B.
N1 - Funding Information:
This research was funded by NIH grants R29DK47256, R01DK51716, TD32DK37352, and P30DK26687.
PY - 1999
Y1 - 1999
N2 - OBJECTIVE: In epidemiological studies, weight loss is usually associated with increased mortality rate. Contrarily, among obese people, weight loss reduces other risk factors for disease and death. We hypothesised that this paradox could exist because weight is used as an implicit adiposity index. No study has considered the independent effects of weight loss and fat loss on mortality rate. We studied mortality rate as a function of weight loss and fat loss. DESIGN: Analysis of 'time to death' in two prospective population-based cohort studies, the Tecumseh Community Health Study (1890 subjects; 321 deaths within 16 y of follow-up) and the Framingham Heart Study (2731 subjects; 507 deaths within 8 y of follow-up), in which weight and fat (via skinfolds) loss were assessable. RESULTS: In both studies, regardless of the statistical approach, weight loss was associated with an increased, and fat loss with a decreased, mortality rate (P < 0.05). Each standard deviation (s.d.) of weight loss (4.6 kg in Tecumseh, 6.7 kg in Framingham) was estimated to increase the hazard rate by 29% (95% confidence interval CI), (14%, 47%, respectively) and 39% (95% CI, 25%, 54% respectively), in the two samples. Contrarily, each s.d. of fat loss (10.0 mm in Tecumseh, 4.8 mm in Framingham) was estimated to reduce the hazard rate 15% (95% CI, 4%, 25%) and 17% (95% CI, 8%, 25%) in Tecumseh and Framingham, respectively. Generalisability of these results to severely (that is, body mass index BMI ≥ 34) obese individuals is unclear. CONCLUSIONS: Among individuals that are not severely obese, weight loss is associated with increased mortality rate and fat loss with decreased mortality rate.
AB - OBJECTIVE: In epidemiological studies, weight loss is usually associated with increased mortality rate. Contrarily, among obese people, weight loss reduces other risk factors for disease and death. We hypothesised that this paradox could exist because weight is used as an implicit adiposity index. No study has considered the independent effects of weight loss and fat loss on mortality rate. We studied mortality rate as a function of weight loss and fat loss. DESIGN: Analysis of 'time to death' in two prospective population-based cohort studies, the Tecumseh Community Health Study (1890 subjects; 321 deaths within 16 y of follow-up) and the Framingham Heart Study (2731 subjects; 507 deaths within 8 y of follow-up), in which weight and fat (via skinfolds) loss were assessable. RESULTS: In both studies, regardless of the statistical approach, weight loss was associated with an increased, and fat loss with a decreased, mortality rate (P < 0.05). Each standard deviation (s.d.) of weight loss (4.6 kg in Tecumseh, 6.7 kg in Framingham) was estimated to increase the hazard rate by 29% (95% confidence interval CI), (14%, 47%, respectively) and 39% (95% CI, 25%, 54% respectively), in the two samples. Contrarily, each s.d. of fat loss (10.0 mm in Tecumseh, 4.8 mm in Framingham) was estimated to reduce the hazard rate 15% (95% CI, 4%, 25%) and 17% (95% CI, 8%, 25%) in Tecumseh and Framingham, respectively. Generalisability of these results to severely (that is, body mass index BMI ≥ 34) obese individuals is unclear. CONCLUSIONS: Among individuals that are not severely obese, weight loss is associated with increased mortality rate and fat loss with decreased mortality rate.
KW - Body mass index
KW - Fat loss
KW - Longevity
KW - Mortality
KW - Obesity
KW - Weight loss
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U2 - 10.1038/sj.ijo.0800875
DO - 10.1038/sj.ijo.0800875
M3 - Article
C2 - 10411233
AN - SCOPUS:0033054795
SN - 0307-0565
VL - 23
SP - 603
EP - 611
JO - International Journal of Obesity
JF - International Journal of Obesity
IS - 6
ER -