Body-mass index and all-cause mortality: individual-participant-data meta-analysis of 239 prospective studies in four continents

Disease areas:

• nutrition and metabolism

Last updated:

19 November 2025

Author(s):

The Global BMI Mortality Collaboration, Emanuele Di Angelantonio, Shilpa N Bhupathiraju, David Wormser, Pei Gao, Stephen Kaptoge, Amy Berrington de Gonzalez, Benjamin J Cairns, Rachel Huxley, Chandra L Jackson, Grace Joshy, Sarah Lewington, JoAnn E Manson, Neil Murphy, Alpa V Patel, Jonathan M Samet, Mark Woodward, Wei Zheng, Maigen Zhou, Narinder Bansal, Aurelio Barricarte, Brian Carter, James R Cerhan, Rory Collins, George Davey Smith, Xianghua Fang, Oscar H Franco, Jane Green, Jim Halsey, Janet S Hildebrand, Keum Ji Jung, Rosemary J Korda, Dale F McLerran, Steven C Moore, Linda M O'Keeffe, Ellie Paige, Anna Ramond, Gillian K Reeves, Betsy Rolland, Carlotta Sacerdote, Naveed Sattar, Eleni Sofianopoulou, June Stevens, Michael Thun, Hirotsugu Ueshima, Ling Yang, Young Duk Yun, Peter Willeit, Emily Banks, Valerie Beral, Zhengming Chen, Susan M Gapstur, Marc J Gunter, Patricia Hartge, Sun Ha Jee, Tai-Hing Lam, Richard Peto, John D Potter, Walter C Willett, Simon G Thompson, John Danesh, Frank B Hu

Publish date:

13 July 2016

Journal:

The Lancet

PubMed ID:

27423262

DOI:

10.1016/s0140-6736(16)30175-1

Abstract

BACKGROUND: Overweight and obesity are increasing worldwide. To help assess their relevance to mortality in different populations we conducted individual-participant data meta-analyses of prospective studies of body-mass index (BMI), limiting confounding and reverse causality by restricting analyses to never-smokers and excluding pre-existing disease and the first 5 years of follow-up.

METHODS: Of 10 625 411 participants in Asia, Australia and New Zealand, Europe, and North America from 239 prospective studies (median follow-up 13·7 years, IQR 11·4-14·7), 3 951 455 people in 189 studies were never-smokers without chronic diseases at recruitment who survived 5 years, of whom 385 879 died. The primary analyses are of these deaths, and study, age, and sex adjusted hazard ratios (HRs), relative to BMI 22·5-<25·0 kg/m(2).

FINDINGS: All-cause mortality was minimal at 20·0-25·0 kg/m(2) (HR 1·00, 95% CI 0·98-1·02 for BMI 20·0-<22·5 kg/m(2); 1·00, 0·99-1·01 for BMI 22·5-<25·0 kg/m(2)), and increased significantly both just below this range (1·13, 1·09-1·17 for BMI 18·5-<20·0 kg/m(2); 1·51, 1·43-1·59 for BMI 15·0-<18·5) and throughout the overweight range (1·07, 1·07-1·08 for BMI 25·0-<27·5 kg/m(2); 1·20, 1·18-1·22 for BMI 27·5-<30·0 kg/m(2)). The HR for obesity grade 1 (BMI 30·0-<35·0 kg/m(2)) was 1·45, 95% CI 1·41-1·48; the HR for obesity grade 2 (35·0-<40·0 kg/m(2)) was 1·94, 1·87-2·01; and the HR for obesity grade 3 (40·0-<60·0 kg/m(2)) was 2·76, 2·60-2·92. For BMI over 25·0 kg/m(2), mortality increased approximately log-linearly with BMI; the HR per 5 kg/m(2) units higher BMI was 1·39 (1·34-1·43) in Europe, 1·29 (1·26-1·32) in North America, 1·39 (1·34-1·44) in east Asia, and 1·31 (1·27-1·35) in Australia and New Zealand. This HR per 5 kg/m(2) units higher BMI (for BMI over 25 kg/m(2)) was greater in younger than older people (1·52, 95% CI 1·47-1·56, for BMI measured at 35-49 years vs 1·21, 1·17-1·25, for BMI measured at 70-89 years; pheterogeneity<0·0001), greater in men than women (1·51, 1·46-1·56, vs 1·30, 1·26-1·33; pheterogeneity<0·0001), but similar in studies with self-reported and measured BMI.

INTERPRETATION: The associations of both overweight and obesity with higher all-cause mortality were broadly consistent in four continents. This finding supports strategies to combat the entire spectrum of excess adiposity in many populations.

FUNDING: UK Medical Research Council, British Heart Foundation, National Institute for Health Research, US National Institutes of Health.