Food production is a major driver of greenhouse gas (GHG) emissions, water and land use, and dietary risk factors are contributors to non-communicable diseases. Shifts in dietary patterns can therefore potentially provide benefits for both the environment and health. However, there is uncertainty about the magnitude of these impacts, and the dietary changes necessary to achieve them. We systematically review the evidence on changes in GHG emissions, land use, and water use, from shifting current dietary intakes to environmentally sustainable dietary patterns. We find 14 common sustainable dietary patterns across reviewed studies, with reductions as high as 70–80% of GHG emissions and land use, and 50% of water use (with medians of about 20–30% for these indicators across all studies) possible by adopting sustainable dietary patterns. Reductions in environmental footprints were generally proportional to the magnitude of animal-based food restriction. Dietary shifts also yielded modest benefits in all-cause mortality risk. Our review reveals that environmental and health benefits are possible by shifting current Western diets to a variety of more sustainable dietary patterns.

Bill & Melinda Gates Foundation and US National Institutes of Health.

Summary Background India's 2011 census revealed a growing imbalance between the numbers of girls and boys at ages 0–6 years, which we hypothesise is due to increased prenatal sex determination followed by selective abortion of female foetuses. Methods We examined sex ratios by birth order among 0.25 million births in three rounds of the nationally-representative National Family Health Survey covering the period from 1990 to 2005. We estimated totals of selective female abortion by examining the birth cohorts of children aged 0–6 years in the 1991, 2001 and 2011 censuses. Findings The conditional sex ratio for second order births when the firstborn was a girl fell from 906 per 1000 boys in 1990 (99%CI 798–1013) to 836 in 2005 (99%CI 733–939); an annual decline of 0.5% (p for trend=0·001). Declines were much greater in mothers with 10 or more years of education than in illiterate mothers, and in wealthier households compared to poorer households. In contrast, no significant declines were noted in the sex ratio for second order births if the firstborn was a male, or for firstborns. Between the 2001 and 2011 censuses, more than twice the number of Indian districts (local administrative areas) showed declines in the child sex ratio as districts showing no change or increases. After adjusting for excess mortality rates in girls, the estimated number of selective female abortions rose from 0 to 2.0 million in the 1980s, 1.2 to 4.1 million in the 1990s, and 3.1 to 6.0 in the 2000s. Each 1% decline in child sex ratio at ages 0–6 years implied 1.2 to 3.6 million more selective female abortions. Selective female abortions totalled about 4.2 to 12.1 million from 1980–2010, with a greater rate of increase in the 1990s than in the 2000s. Interpretation Selective abortion of female foetuses, especially for pregnancies following a firstborn girl, has increased substantially in India. Most of India's population now live in states where selective female abortion is common. Funding US National Institutes of Health, Canadian Institute of Health Research, International Development Research Centre, Li Ka Shing Knowledge Institute.