Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities^1,2. This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity^3–6. Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017—and more than 80% in some low- and middle-income regions—was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing—and in some countries reversal—of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.

Background. The study aimed to evaluate the risk of hepatitis C virus (HCV) infection on hepatic and extrahepatic deaths. Methods. A cohort of 23 820 adults aged 30–65 years old were enrolled during 1991–1992. The seromarkers hepatitis B surface antigen (HBsAg), anti-HCV, and serum HCV RNA levels at study entry were tested. The vital status was ascertained through computerized linkage with national death certification profiles from 1991 to 2008. Results. There were 19 636 HBsAg-seronegatives, including 18 541 anti-HCV seronegatives and 1095 anti-HCV seropositives. Among anti-HCV seropositives, 69.4% had detectable serum HCV RNA levels. There were 2394 deaths that occurred during an average follow-up period of 16.2 years. Compared with anti-HCV seronegatives, anti-HCV seropositives had higher mortality from both hepatic and extrahepatic diseases, showing multivariate-adjusted hazard ratio (95% confidence interval) of 1.89 (1.66–2.15) for all causes of death; 12.48 (9.34–16.66) for hepatic diseases; 1.35 (1.15–1.57) for extrahepatic diseases; 1.50 (1.10–2.03) for circulatory diseases; 2.77 (1.49–5.15) for nephritis, nephrotic syndrome, and nephrosis; 4.08 (1.38–12.08) for esophageal cancer; 4.19 (1.18–14.94) for prostate cancer; and 8.22 (1.36–49.66) for thyroid cancer. Anti-HCV seropositives with detectable HCV RNA levels had significantly higher mortality from hepatic and extrahepatic diseases than anti-HCV seropositives with undetectable HCV RNA. Conclusions. Monitoring HCV RNA in anti-HCV seropositives is essential for the prediction of mortality associated with hepatitis C.

Objective To evaluate the association between body mass index and mortality from overall cardiovascular disease and specific subtypes of cardiovascular disease in east and south Asians. Design Pooled analyses of 20 prospective cohorts in Asia, including data from 835 082 east Asians and 289 815 south Asians. Cohorts were identified through a systematic search of the literature in early 2008, followed by a survey that was sent to each cohort to assess data availability. Setting General populations in east Asia (China, Taiwan, Singapore, Japan, and Korea) and south Asia (India and Bangladesh). Participants 1 124 897 men and women (mean age 53.4 years at baseline). Main outcome measures Risk of death from overall cardiovascular disease, coronary heart disease, stroke, and (in east Asians only) stroke subtypes. Results 49 184 cardiovascular deaths (40 791 in east Asians and 8393 in south Asians) were identified during a mean follow-up of 9.7 years. East Asians with a body mass index of 25 or above had a raised risk of death from overall cardiovascular disease, compared with the reference range of body mass index (values 22.5-24.9; hazard ratio 1.09 (95% confidence interval 1.03 to 1.15), 1.27 (1.20 to 1.35), 1.59 (1.43 to 1.76), 1.74 (1.47 to 2.06), and 1.97 (1.44 to 2.71) for body mass index ranges 25.0-27.4, 27.5-29.9, 30.0-32.4, 32.5-34.9, and 35.0-50.0, respectively). This association was similar for risk of death from coronary heart disease and ischaemic stroke; for haemorrhagic stroke, the risk of death was higher at body mass index values of 27.5 and above. Elevated risk of death from cardiovascular disease was also observed at lower categories of body mass index (hazard ratio 1.19 (95% confidence interval 1.02 to 1.39) and 2.16 (1.37 to 3.40) for body mass index ranges 15.0-17.4 and <15.0, respectively), compared with the reference range. In south Asians, the association between body mass index and mortality from cardiovascular disease was less pronounced than that in east Asians. South Asians had an increased risk of death observed for coronary heart disease only in individuals with a body mass index greater than 35 (hazard ratio 1.90, 95% confidence interval 1.15 to 3.12). Conclusions Body mass index shows a U shaped association with death from overall cardiovascular disease among east Asians: increased risk of death from cardiovascular disease is observed at lower and higher ranges of body mass index. A high body mass index is a risk factor for mortality from overall cardiovascular disease and for specific diseases, including coronary heart disease, ischaemic stroke, and haemorrhagic stroke in east Asians. Higher body mass index is a weak risk factor for mortality from cardiovascular disease in south Asians.

Cancer registration provides core information for cancer surveillance and control. The population-based Taiwan Cancer Registry was implemented in 1979. After the Cancer Control Act was promulgated in 2003, the completeness (97%) and data quality of cancer registry database has achieved at an excellent level. Hospitals with 50 or more beds, which provide outpatient and hospitalized cancer care, are recruited to report 20 items of information on all newly diagnosed cancers to the central registry office (called short-form database). The Taiwan Cancer Registry is organized and funded by the Ministry of Health and Welfare. The National Taiwan University has been contracted to operate the registry and organized an advisory board to standardize definitions of terminology, coding and procedures of the registry's reporting system since 1996. To monitor the cancer care patterns and evaluate the cancer treatment outcomes, central cancer registry has been reformed since 2002 to include detail items of the stage at diagnosis and the first course of treatment (called long-form database). There are 80 hospitals, which count for >90% of total cancer cases, involved in the long-form registration. The Taiwan Cancer Registry has run smoothly for >30 years, which provides essential foundation for academic research and cancer control policy in Taiwan.