title: Obesity and mortality: are the risks declining? Evidence from multiple prospective studies in the United States.
abstract: We evaluated whether the obesity-associated years of life lost (YLL) have decreased over calendar time. We implemented a meta-analysis including only studies with two or more serial body mass index (BMI) assessments at different calendar years. For each BMI category (normal weight: BMI 18.5 to <25 [reference]; overweight: BMI 25 to <30; grade 1 obesity: BMI 30 to <35; and grade 2-3 obesity: BMI ≥ 35), we estimated the YLL change between 1970 and 1990. Because of low sample sizes for African-American, results are reported on Caucasian. Among men aged ≤60 years YLL for grade 1 obesity increased by 0.72 years (P < 0.001) and by 1.02 years (P = 0.01) for grade 2-3 obesity. For men aged >60, YLL for grade 1 obesity decreased by 1.02 years (P < 0.001) and increased by 0.63 years for grade 2-3 obesity (P = 0.63). Among women aged ≤60, YLL for grade 1 obesity decreased by 4.21 years (P < 0.001) and by 4.97 years (P < 0.001) for grade 2-3 obesity. In women aged >60, YLL for grade 1 obesity decreased by 3.98 years (P < 0.001) and by 2.64 years (P = 0.001) for grade 2-3 obesity. Grade 1 obesity's association with decreased longevity has reduced for older Caucasian men. For Caucasian women, there is evidence of a decline in the obesity YLL association across all ages.
authors.affiliation: Department of Biostatistics, Office of Energetics and Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: T
authors.initials: T
authors.lastname: Mehta
authors.forename: K R
authors.initials: KR
authors.lastname: Fontaine
authors.forename: S W
authors.initials: SW
authors.lastname: Keith
authors.forename: S S
authors.initials: SS
authors.lastname: Bangalore
authors.forename: G
authors.initials: G
authors.lastname: de los Campos
authors.forename: A
authors.initials: A
authors.lastname: Bartolucci
authors.forename: N M
authors.initials: NM
authors.lastname: Pajewski
authors.forename: D B
authors.initials: DB
authors.lastname: Allison
mesh_terms: D015992:Body Mass Index; D002423:Cause of Death; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000401:mortality*; D011446:Prospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014481:United States / Q000453:epidemiology; D044465:White People
keywords: Length of follow-up; maturation; recency; study-level variation