Table 6.
Diet-related health impact analyses of environmentally sustainable diets
| Health considerations | Environmental considerations | ||||||
|---|---|---|---|---|---|---|---|
| Reference | Country | Dietary data | Dietary counterfactuals | Dietary exposure | Measure of health impact including the health-disease outcomes under study | Food aggregation level* | Environmental indicator |
| Friel et al. (2009)( 49 ) | UK Brazil | Individual level 4/7 d diet record (UK National Diet and Nutrition Surveys 1998, 2000 and 2003) 1×24 h recall (São Paulo Household Health Survey 2006) | 30 % decrease in the consumption of animal-based products | Decreased intake in saturated fat with increase in polyunsaturated fat | DALY YLL for IHD | / | Livestock production¶ |
| Aston et al. (2012)( 47 ) | UK | Individual level 7 d diet record (UK National Diet and Nutrition Survey 2000–2001) | Counterfactual dietary distribution in which the proportion of vegetarians is doubled and all the non-vegetarians adopt a dietary pattern similar to that of the lowest red and processed meat consumers | Decreased intake of red and processed meat | Potential impact fractions§ for CHD, diabetes mellitus and colorectal cancers | 45 categories | GHGE |
| Scarborough et al. (2012)( 31 ) | UK | Household level Per household 2-week food purchases (Family Food Survey 2008) | 50 % decrease in the consumption of all meat and dairy products A shift from red to white meat A 50 % decrease in white meat products | Decreased intake of meat and/or dairy, and isoenergetic increased intake of fruit and vegetables, and cereals | Total deaths delayed or averted in the UK under each dietary counterfactual using the DIETRON model|| | 256 categories | GHGE |
| Briggs et al. (2013)( 32 ) | UK | Household level Per household 2-week food purchases (Living Costs and Food Survey 2010) | Tax scenarios: a tax of £2·72/t CO2e per 100 g product applied to all food and drink groups with GHGE above average Tax and subsidy scenario: including subsidies for food groups with GHGE below average | Decreased intake of food items with GHGE above average, and increased intake of food items with GHGE below average | Total death delayed or averted in the UK under each dietary counterfactual using the DIETRON model|| | 256 categories | GHGE |
| Milner et al. (2015)( 48 ) | UK | Individual level 4 d diet record (UK National Diet and Nutrition Survey 2010) | Optimised diet to achieve WHO guidelines with no GHGE reduction target and with a 10–60 % reduction target( 46 ) | Decreased intake of red and processed meat, and increased intake of fruit and non-starchy vegetables | YLL for CHD, stroke, type 2 diabetes, cancers of the mouth/pharynx/larynx, oesophagus, lung, stomach and colon/rectum | 42 groups | GHGE |
| Temme et al. (2015)( 54 ) | Netherlands | Individual level 2×24 h recalls (Dutch National Food Consumption Survey 2007–2010) | Population stratification by environmental sustainability (i.e. diets of low, intermediate or high environmental load) | Dietary intake by diets of low, intermediate or high environmental load | Descriptive comparison of the food intake, energy intake and nutrient intake | 254 items | GHGE |
| Biesbroek et al. (2014)( 60 )† | Netherlands | Individual level EPIC-NL FFQ (178-item, semi-quantitative, 1993–1997) | Population stratification by environmental sustainability (i.e. quartiles) Meat-substitution diets; one-third reduction in meat intake (35 g) of the average daily meat intake (105 g)‡ | Environmental sustainability or replacement option | Crude and adjusted hazard ratios (for age, sex and energy intake) using Cox proportional hazard models for all-cause mortality Cause-specific mortality (including cancer, CVD, respiratory diseases and other causes) | 254 items | GHGE Land use |
EPIC-NL, European Prospective Investigation into Cancer and Nutrition–Netherlands cohort; CO2e, CO2 equivalents; GHGE, greenhouse gas emissions; DALY, disability-adjusted life years; YLL, years of life lost.
Food aggregation level: the number of food items or groups (depending on author’s terminology) for which environmental sustainability data of food intake was available.
The analysis of the health impact (i.e. mortality survival analysis) was based on data from 35 057 subjects included in EPIC-NL, a prospective cohort study with a median follow-up of 15·9 years. The main aim was to investigate the relationship between diet-related sustainability and mortality outcomes either by population stratification for the environmental indicators (e.g. GHGE and land use) or by meat-substitution scenarios.
In the meat-substitution scenario, the replacement of meat was compensated by means of food weight and the plant-based meat-substitutes were potatoes, total vegetables, total fruit/nuts/seeds, pasta/rice/couscous, cheese, milk-based desserts or fish, representing acceptable alternatives for meat because these foods are consumed in significant amounts in the Dutch diet and can replace meat in a hot meal. The reduction in all-cause mortality risk and environmental impact was estimated separately per meat-substitution option and for an option with no replacement.
Potential impact fraction was calculated as the difference between current aggregate risk and aggregate risk under counterfactual divided by current aggregate risk, and represents the proportion/percentage of disease in the population that can be attributed to the current diet and therefore could potentially have been avoided under the counterfactual diet.
The DIETRON model included the intake of total energy, fruit, vegetables, fibre, total fat, mono- and polyunsaturated, saturated and trans-fatty acids, dietary cholesterol and salt as dietary input to estimate the link between food consumption and mortality using age- and sex-specific relative risk estimates from meta-analyses.
A 30 % decrease in livestock production is assumed to result in a reduction of equal size in the consumption of animal-based products, and thus a decrease in the dietary intake of saturated fat.