Healthy and sustainable diets that meet greenhouse gas emission reduction targets and are affordable for different income groups in the UK.

OBJECTIVE: To model dietary changes required to shift the UK population to diets that meet dietary recommendations for health, have lower greenhouse gas emissions (GHGE) and are affordable for different income groups. DESIGN: Linear programming was used to create diets that meet dietary requirements for health and reduced GHGE (57 and 80 % targets) by income quintile, taking account of food budgets and foods currently purchased, thereby keeping dietary change to a minimum.Setting/ParticipantsNutrient composition, GHGE and price data were mapped to 101 food groups in household food purchase data (UK Living Cost and Food Survey (2013), 5144 households). RESULTS: Current diets of all income quintiles had similar total GHGE, but the source of GHGE differed by types of meat and amount of fruit and vegetables. It was possible to create diets with a 57 % reduction in GHGE that met dietary and cost restraints in all income groups. In the optimised diets, the food sources of GHGE differed by income group due to the cost and keeping the level of deviation from current diets to a minimum. Broadly, the changes needed were similar across all groups; reducing animal-based products and increasing plant-based foods but varied by specific foods. CONCLUSIONS: Healthy and lower-GHGE diets could be created in all income quintiles but tailoring changes to income groups to minimise deviation may make dietary changes more achievable. Specific attention must be given to make interventions and policies appropriate for all income groups.

Greenhouse gas emissions and water footprints of typical dietary patterns in India.

Agriculture is a major contributor to India's environmental footprint, particularly through greenhouse gas (GHG) emissions from livestock and fresh water used for irrigation. These impacts are likely to increase in future as agriculture attempts to keep pace with India's growing population and changing dietary preferences. Within India there is considerable dietary variation, and this study therefore aimed to quantify the GHG emissions and water usage associated with distinct dietary patterns. Five distinct diets were identified from the Indian Migration Study - a large adult population sample in India - using finite mixture modelling. These were defined as: Rice & low diversity, Rice & fruit, Wheat & pulses, Wheat, rice & oils, Rice & meat. The GHG emissions of each dietary pattern were quantified based on a Life Cycle Assessment (LCA) approach, and water use was quantified using Water Footprint (WF) data. Mixed-effects regression models quantified differences in the environmental impacts of the dietary patterns. There was substantial variability between diets: the rice-based patterns had higher associated GHG emissions and green WFs, but the wheat-based patterns had higher blue WFs. Regression modelling showed that the Rice & meat pattern had the highest environmental impacts overall, with 0.77 (95% CI 0.64-0.89) kg CO2e/capita/day (31%) higher emissions, 536 (95% CI 449-623) L/capita/day (24%) higher green WF and 109 (95% CI 85.9-133) L/capita/day (19%) higher blue WF than the reference Rice & low diversity pattern. Diets in India are likely to become more diverse with rising incomes, moving away from patterns such as the Rice & low diversity diet. Patterns such as the Rice & meat diet may become more common, and the environmental consequences of such changes could be substantial given the size of India's population. As global environmental stress increases, agricultural and nutrition policies must recognise the environmental impacts of potential future dietary changes.

Effect of increasing fruit and vegetable intake by dietary intervention on nutritional biomarkers and attitudes to dietary change: a randomised trial.

PURPOSE: Low fruit and vegetable consumption is linked with an increased risk of death from vascular disease and cancer. The benefit of eating fruits and vegetables is attributed in part to antioxidants, vitamins and phytochemicals. Whether increasing intake impacts on markers of disease remains to be established. This study investigates whether increasing daily intake of fruits, vegetables and juices from low (approx. 3 portions), to high intakes (approx. 8 portions) impacts on nutritional and clinical biomarkers. Barriers to achieving the recommended fruit and vegetable intakes are also investigated. METHOD: In a randomised clinical trial, the participants [19 men and 26 women (39-58 years)] with low reported fruit, juice and vegetable intake (<3 portions/day) were randomised to consume either their usual diet or a diet supplemented with an additional 480 g of fruit and vegetables and fruit juice (300 ml) daily for 12 weeks. Nutritional biomarkers (vitamin C, carotenoids, B vitamins), antioxidant capacity and genomic stability were measured pre-intervention, at 4-, 8- and 12 weeks throughout the intervention. Samples were also taken post-intervention after a 6-week washout period. Glucose, homocysteine, lipids, blood pressure, weight and arterial stiffness were also measured. Intake of fruit, fruit juice and vegetables was reassessed 12 months after conducting the study and a questionnaire was developed to identify barriers to healthy eating. RESULTS: Intake increased significantly in the intervention group compared to controls, achieving 8.4 portions/day after 12 weeks. Plasma vitamin C (35%), folate (15%) and certain carotenoids [α-carotene (50%) and ß-carotene (70%) and lutein/zeaxanthin (70%)] were significantly increased (P < 0.05) in the intervention group. There were no significant changes in antioxidant capacity, DNA damage and markers of vascular health. Barriers to achieving recommended intakes of fruits and vegetables measured 12 months after the intervention period were amount, inconvenience and cost. CONCLUSION: While increasing fruit, juice and vegetable consumption increases circulating level of beneficial nutrients in healthy subjects, a 12-week intervention was not associated with effects on antioxidant status or lymphocyte DNA damage. TRIAL REGISTRATION: This trial was registered at Controlled-Trials.com; registration ISRCTN71368072.

Socio-economic differences in diet, physical activity and leisure-time screen use among Scottish children in 2006 and 2010: are we closing the gap?

OBJECTIVE: To investigate socio-economic differences in children's diet, activity and inactivity and changes in these differences over 4 years during which new policies on food in schools were introduced. DESIGN: Two cross-sectional surveys in which diet was assessed by FFQ and physical activity and inactivity were assessed by interviewer-administered questionnaire. Socio-economic status was assessed by the area-based Scottish Index of Multiple Deprivation. SETTING: Scotland, 2006 and 2010. SUBJECTS: Children aged 3-17 years (n 1700 in 2006, n 1906 in 2010). RESULTS: In both surveys there were significant linear associations between socio-economic deprivation and intakes of energy, non-milk extrinsic sugars (NMES) as a percentage of food energy, sugar-sweetened beverages, confectionery, crisps and savoury snacks and leisure-time screen use (all higher among children in more deprived areas), while intakes of fruit, fruit juice and vegetables showed the opposite trend. In 2010 children in more deprived areas engaged in more physical activity out of school than those in more affluent areas, but between 2006 and 2010 there was an overall reduction in physical activity out of school. There were also small but statistically significant overall reductions in intakes of confectionery, crisps and savoury snacks, energy and NMES and saturated fat as a percentage of food energy, but no statistically significant change in socio-economic gradients in diet or activity between the two surveys. CONCLUSIONS: Interventions to improve diet and physical activity in children in Scotland need to be designed so as to be effective in all socio-economic groups.

Greenhouse gas emissions from agricultural food production to supply Indian diets: Implications for climate change mitigation.

Agriculture is a major source of greenhouse gas (GHG) emissions globally. The growing global population is putting pressure on agricultural production systems that aim to secure food production while minimising GHG emissions. In this study, the GHG emissions associated with the production of major food commodities in India are calculated using the Cool Farm Tool. GHG emissions, based on farm management for major crops (including cereals like wheat and rice, pulses, potatoes, fruits and vegetables) and livestock-based products (milk, eggs, chicken and mutton meat), are quantified and compared. Livestock and rice production were found to be the main sources of GHG emissions in Indian agriculture with a country average of 5.65 kg CO2eq kg-1 rice, 45.54 kg CO2eq kg-1 mutton meat and 2.4 kg CO2eq kg-1 milk. Production of cereals (except rice), fruits and vegetables in India emits comparatively less GHGs with <1 kg CO2eq kg-1 product. These findings suggest that a shift towards dietary patterns with greater consumption of animal source foods could greatly increase GHG emissions from Indian agriculture. A range of mitigation options are available that could reduce emissions from current levels and may be compatible with increased future food production and consumption demands in India.

Achieving dietary recommendations and reducing greenhouse gas emissions: modelling diets to minimise the change from current intakes.

BACKGROUND: Average population dietary intakes do not reflect the wide diversity of dietary patterns across the population. It is recognised that most people in the UK do not meet dietary recommendations and have diets with a high environmental impact, but changing dietary habits has proved very difficult. The purpose of this study was to investigate the diversity in dietary changes needed to achieve a healthy diet and a healthy diet with lower greenhouse gas emissions (GHGE) (referred to as a sustainable diet) by taking into account each individual's current diet and then minimising the changes they need to make. METHODS: Linear programming was used to construct two new diets for each adult in the UK National Diet and Nutrition Survey (n = 1491) by minimising the changes to their current intake. Stepwise changes were applied until (i) dietary recommendations were achieved and (ii) dietary recommendations and a GHGE target were met. First, gradual changes (≤50%) were made to the amount of any foods currently eaten. Second, new foods were added to the diet. Third, greater reductions (≤75%) were made to the amount of any food currently eaten and finally, foods were removed from the diet. RESULTS: One person out of 1491 in the sample met all the dietary requirements based on their reported dietary intake. Only 7.5 and 4.6 % of people achieved a healthy diet and a sustainable diet, respectively, by changing the amount of any food they currently ate by up to 50 %. The majority required changes to the amount of each food eaten plus the addition of new foods. Fewer than 5 % had to remove foods they ate to meet recommendations. Sodium proved the most difficult nutrient recommendation to meet. The healthy diets and sustainable diets produced a 15 and 27 % reduction in greenhouse gas emissions respectively. CONCLUSIONS: Since healthy diets alone do not produce substantial reductions in greenhouse gas emissions, dietary guidelines need to include recommendations for environmental sustainability. Minimising the shift from current dietary intakes is likely to make dietary change more realistic and achievable.

Global cropland and greenhouse gas impacts of UK food supply are increasingly located overseas.

Producing sufficient, healthy food for a growing world population amid a changing climate is a major challenge for the twenty-first century. Agricultural trade could help alleviate this challenge by using comparative productivity advantages between countries. However, agricultural trade has implications for national food security and could displace environmental impacts from developed to developing countries. This study illustrates the global effects resulting from the agricultural trade of a single country, by analysing the global cropland and greenhouse gas impacts of the UK's food and feed supply. The global cropland footprint associated with the UK food and feed supply increased by 2022 kha (+23%) from 1986 to 2009. Greenhouse gas emissions (GHGE) associated with fertilizer and manure application, and rice cultivation remained relatively constant at 7.9 Mt CO2e between 1987 and 2008. Including GHGE from land-use change, however, leads to an increase from 19.1 in 1987 to 21.9 Mt CO2e in 2008. The UK is currently importing over 50% of its food and feed, whereas 70% and 64% of the associated cropland and GHGE impacts, respectively, are located abroad. These results imply that the UK is increasingly reliant on external resources and that the environmental impact of its food supply is increasingly displaced overseas.

A Brief Educational Intervention Increases Knowledge of the Sugar Content of Foods and Drinks but Does Not Decrease Intakes in Scottish Children Aged 10-12 Years.

OBJECTIVE: To assess the effectiveness of an educational intervention to improve children's knowledge of the sugar content of food and beverages. METHODS: Cluster-randomized, controlled trial with 268 children (aged 10-12 years) from 14 primary schools in Aberdeen, Scotland. The intervention group received 2 interactive classroom sessions about sugar. A questionnaire to assess knowledge was completed at baseline and 4, 10, and 34 weeks postintervention. Dietary intake was assessed by food frequency questionnaire at baseline and on weeks 10 and 34. RESULTS: After the intervention, the intervention group demonstrated greater knowledge of sugar than did the control group (P < .001), which was sustained at week 34 (P < .001). Dietary intakes of sugar did not change postintervention. Pre-intervention children underestimated the sugar content of fruit-based beverages. CONCLUSIONS AND IMPLICATIONS: Children's knowledge of sugar in food and beverages is limited but can be improved through a simple educational intervention. Further intervention would be needed to encourage a change in dietary intake.

Sustainable diets for the future: Can we contribute to reducing greenhouse gas emissions by eating a healthy diet?

BACKGROUND: Food systems account for 18-20% of UK annual greenhouse gas emissions (GHGEs). Recommendations for improving food choices to reduce GHGEs must be balanced against dietary requirements for health. OBJECTIVE: We assessed whether a reduction in GHGEs can be achieved while meeting dietary requirements for health. DESIGN: A database was created that linked nutrient composition and GHGE data for 82 food groups. Linear programming was used iteratively to produce a diet that met the dietary requirements of an adult woman (19-50 y old) while minimizing GHGEs. Acceptability constraints were added to the model to include foods commonly consumed in the United Kingdom in sensible quantities. A sample menu was created to ensure that the quantities and types of food generated from the model could be combined into a realistic 7-d diet. Reductions in GHGEs of the diets were set against 1990 emission values. RESULTS: The first model, without any acceptability constraints, produced a 90% reduction in GHGEs but included only 7 food items, all in unrealistic quantities. The addition of acceptability constraints gave a more realistic diet with 52 foods but reduced GHGEs by a lesser amount of 36%. This diet included meat products but in smaller amounts than in the current diet. The retail cost of the diet was comparable to the average UK expenditure on food. CONCLUSION: A sustainable diet that meets dietary requirements for health with lower GHGEs can be achieved without eliminating meat or dairy products or increasing the cost to the consumer.

Dietary patterns of school-age children in Scotland: association with socio-economic indicators, physical activity and obesity.

The Survey of Sugar Intake among Children in Scotland was carried out in May to September 2006. The present study aimed to identify dietary patterns in school-aged children from the survey and investigate associations with socio-economic factors, obesity and physical activity. Habitual diet was assessed using the Scottish Collaborative Group FFQ. Height and weight were measured by trained fieldworkers. A total of 1233 FFQ were available for analysis. Dietary patterns were identified by age (5-11 and 12-17 years) and sex using principal components analysis. Associations between factor scores and socio-economic status, education level of the main food provider, physical activity levels and BMI category (based on UK 1990 charts) were examined. Three dietary patterns were identified in each age and sex group. 'Healthier' patterns loading highly for fruit and vegetables were significantly associated with higher socio-economic status and higher education levels of the main food provider whereas more 'unhealthy' patterns ('snacks' and 'puddings') were associated with lower socio-economic status and lower education levels of the main food provider. There was no consistent association between dietary patterns and BMI group or time spent in physical activity. However, inactivity (screen time) was inversely associated with 'healthier' patterns in all age and sex groups and positively associated with 'puddings' and 'snacks' in girls aged 5-11 years. Clear dietary patterns can be identified in school-age children in Scotland, which are consistently related to socio-economic factors and inactivity. This has implications for targeting health promotion at subgroups in terms of lifestyle changes required.