The outlook for dairy as part of a sustainable diet

Transcription

1 The outlook for dairy as part of a sustainable diet Dr. Ditte Hobbs Research Fellow Hugh Sinclair Unit of Human Nutrition University of Reading 09 February 2016 University of Reading 2015 d.a.hobbs@reading.ac.uk

2 Background Today 2050 Supplying a growing population with sufficient food to meet energy and micronutrient needs is one of the world s greatest challenges. 7 Billion people 9.1 Billion people 2

3 kg/person/year Demand of dairy products increasing Food consumption per person, major commodities Source: Alexandratos N & Bruinsma J. World agriculture towards 2030/2050: the 2012 revision. ESA Working paper No Rome, Italy

4 Nutrition/Health The future position of dairy in the diet Sustainability 4

5 Modelling approach & data sources A predictive response model using Excel was created for adult (19-64 y) males (n=710) and females (n=945). Constructed according to 63 main food groups (excl commercial toddler foods/drinks and dietary supplements) and 136 sub-groups. Food and nutrition data was from years 1-4 of the NDNS (2008/ /12). Financial data was collected by online shopping (Asda and Waitrose) during the months of June to September Environmental data was collected using Life Cycle Analysis (LCA) from primary production to retail for five measures of environmental sustainability: Greenhouse Gas (GHG) emissions Water and land use Eutrophication and acidification potentials 5

6 Using current average UK dietary patterns Dietary patterns of UK adults were identified using NDNS years 1-4 (Bates et al., 2014). Data was split for quartile of dairy intake (g/d). Q1: 0-95 g dairy/day Q2: g dairy/day Q3: g dairy/day Q4: g dairy/day Dairy group food group included milk, cheese, yogurt, ice cream, fromage frais and dairy desserts. To determine statistical differences between food groups according to quartile of dairy intake data were analysed statistically using Analysis of Covariance (ANCOVA) controlling for age and total energy intake (kj). 6

7 UK dietary patterns/scenarios Dairy free (n=21) Wholemeal bread Milk alternatives Eggs Chicken & turkey Potatoes Oily fish Low dairy (n=177) White bread Coated/fried fish Soft drinks Meat pies Coated chicken High dairy (n=178) Brown bread High fibre cereals Cakes, biscuits etc Vegetables Fruit 7

8 Nutritional supply & adequacy: Dairy containing diets Males y P-value Q1 Q2 Q3 Q4 Q1 vs Q4 2 P-value 3 Protein (g/d) Sat fat (g/d) P< P< Thiamin (mg/d) P< P< Riboflavin (mg/d) P< P< Vit B12 (µg/d) P< P< Folate (µg/d) Iron (mg/d) Calcium (mg/d) P< P< Magnesium (mg/d) P< Potassium (mg/d) P< P< Zinc (mg/d) P< P< Iodine (µg/d) P< P< Data is shown as means. 2 Based on Bonferroni post-hoc test comparing the lowest and highest dairy quartiles. 3 Data show differences between nutrient intakes and dairy quartiles, controlling for age and total energy intake (kj/d) using Analysis of Covariance (ANCOVA). 8

9 Nutritional supply & adequacy: Nutrient recommendations Data from: National Diet and Nutrition Survey years 1-4 (combined)

10 Nutrient supply & adequacy: dairy free diets Data from: National Diet and Nutrition Survey years 1-4 (combined)

11 Nutrient supply & adequacy: soya milk based diets 104% Ca RNI Data from: National Diet and Nutrition Survey years 1-4 (combined)

12 Environmental impact of diets containing varying levels of dairy Acidification (gso 2 e/d) P=0.115 Eutrophication (gne/d) P< Land use (m 2 /d) Total water use (L/d) GHGE (kg CO 2 e/d) P< P=0.098 P< Average UK Q1 Q2 Q3 Q4 NOTE: Graph shows adjusted values (gender, age, energy intake (kj)) 12

13 Contribution of food groups to environmental impact NOTE: Table shows food groups that were significantly (P<0.05) across dairy quartiles. 13

14 Financial cost of diets containing varying levels of dairy 8 P< Dietary cost ( /d) Average UK Q1 Q2 Q3 Q4 NOTE: Graph shows adjusted values (gender, age, energy intake (kj)) Financial cost of high dairy diet (Q4) is less than low dairy diet (Q1). 14

15 Carbon & financial cost per unit Dietary patterns that include dairy products provide lower financial cost per nutrient as well as lower GHGEs per nutrient compared with those that are free or low (<95 g) in dairy. 15

16 Conclusions The findings from this modelling study found that excluding dairy foods or having a diet low in dairy, particularly in milk (<95 g/day) may have important nutritional consequences in adults. Dietary patterns representative of the current UK adults that are free or low in dairy products provide higher financial cost and CO 2 eqv per nutrient compared with those that are high in dairy. This predictive response model could be extended to be used to investigate nutritional adequacy, financial and environmental impacts of any dietary patterns or specific dietary change. 16

17 Can healthy diets be sustainable? MacDiarmid et al (2012): Linear programming. 36% reduction in GHGEs by optimizing existing food UK food groups. Still meeting nutrient recommendations. Acceptability and affordability constraints added to model. A sustainable diet that meets dietary requirements for health with 36 % lower GHGEs can be achieved without eliminating meat or dairy products or increasing the cost to the consumer. 17

18 Other diets & Sustainability Saxe et al (2014): New Nordic Diet had 35% less GWP compared with Average Danish Diet. New Nordic Diet had 30% less socioeconomic costs compared with Average Danish Diet. 18

19 What is the health impact of sustainable diets? Number of deaths prevented per year by diets compared with baseline diets Scarborough et al (2012) Scenario 1 (19% GHGs): 50% reduction in meat and dairy, balanced with increase in pant foods. Scenario 2 (9% GHGs): Shift from red meat to white meat, no overall reduction in livestock. Scenario 3 (3% GHGs): 50% reduction in white meat, balanced with increase in plant foods. 19

20 Over consumption and environmental sustainability Scatter plot showing the relationship between energy intake and GHGEs Source: Monsivais et al (2015) 20

21 Outlook on dairy as part of sustainable diets Evaluating the position of dairy in the diet should take into account the impact of both nutritional and environmental factors. Models that optimize total diets, rather than individual food products, for their nutritional and environmental impact are the preferred approach for developing realistic alternative consumption strategies. Modelling should also take into account affordability, food safety, and taste. 21

22 The Team. Prof. Ian Givens Prof. Julie Lovegrove Camilla Durrant John Elliott Dr. Christian Van Stolk 22

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