Vincent Réquillart is a leading thinker at TSE and INRA, Europe’s top agricultural research institute. His innovative work on the impact of dietary and nutritional recommendations on consumer welfare, health and the environment suggests that public information campaigns need to be stepped up. His team is the first to analyze their impact on a consumer’s overall diet.
Many countries use information campaigns to encourage a healthier diet with less fat, sugars and salt and more fruit and vegetables. Studies have also shown that food can be responsible for 15% to 30% of greenhouse gas emissions in developed countries, leading many experts to recommend more ecologically sustainable diets that include less meat.
Changing diet is rarely easy
Information campaigns aimed at raising awareness of food-related health issues generally have positive effects on consumption but are relatively modest in scope. Campaigns such as “5 a day” might contribute to a 5-8% increase in the average consumption of fruit and vegetables. This moderate impact is not surprising as many studies show it is “costly” for consumers to change eating habits. Consumers choose the diet based on their taste preferences, prices, income, time, family environment, and so on. Adopting a recommendation can have long-term health benefits, but often appears as a loss of “well-being” in the short term if new foods are perceived to be less tasty or require more preparation. This loss of well-being must be compared with health and environmental gains to determine whether recommendations are cost-effective.
Adopting a particular recommendation can lead to a change in the overall diet. For example, an increase in fruit and vegetable consumption can lead to a decrease in the consumption of dairy products for dessert. Foods within an individual’s diet are connected by complementarity and substitution relationships that must be characterized to evaluate the effects of a recommendation on the overall diet.
Impact on diets
Using a consumer behavior model, Vincent’s team simulate how the whole diet is modified in response to a recommendation. To assess the impact on health, they use an epidemiological model to quantify the effect of dietary changes on the mortality associated with a set of chronic diseases. The impact on the environment is assessed using emission factors for the main foods consumed in France. Finally, a cost-benefit analysis uses monetary equivalents to compare the variation in consumer welfare with health and environmental impacts.
Vincent and his colleagues assume that, as a result of an information campaign, consumers increase their compliance with a recommendation by 5%. They consider five different recommendations aimed at improving public health:
- Eat more fruit and vegetables
- Consume fewer soft drinks
- Eat more fish and seafood
- Eat more fresh dairy products
- Eat less cheese, butter and cream
Two other recommendations are justified by environmental considerations:
- Eat less meat (as emissions from animals are higher than those of plants)
- Eat less red meat (as emissions from ruminants are higher than those of other animals)
The results show that adopting a recommendation has effects on the overall diet. For example, a 5% increase in consumption of fruit and vegetables translates into lower consumption of red meat, partially offset by increased consumption of other meats, and lower consumption of dairy products. Interestingly, compliance with this recommendation is driven by consumers eating more processed (rather than fresh) fruit and vegetables. Eating less cheese, butter and cream leads to increased consumption of meat.
Health vs environment
The impact of the recommendations on health and emissions varies considerably. All have positive effects on health, especially the fruit and vegetable recommendation. In terms of emissions, the strongest impact comes from eating more fruit and vegetables and to a lesser extent from reduced meat consumption.
Most of the recommendations have compatible health and environmental effects. In the case of cheese, butter and cream, however, a decrease in consumption has a positive effect on health but a negative effect on emissions, largely due to the associated increase in meat consumption.
Except for the meat recommendation, the effect on health is about 10 times the environmental impact in terms of monetary value.
Recommendations are often cost-effective
The costs borne by consumers vary greatly according to the recommendations: the more food categories affected, the greater the costs. Reducing red-meat consumption, for example, has little effect on other products. Conversely, an increase in fruit and vegetable consumption affects many other products.
Eating more fruit and vegetables is clearly desirable: the costs borne by consumers are largely offset by the health and environmental benefits. The recommendations to eat more fish or less red meat are cost-effective, but to a lesser extent. As for reducing consumption of all meat, the benefits of this recommendation are of the same order of magnitude as its costs.
Future research
These results should be considered with caution, Vincent warns. Environmental impact is measured only in terms of emissions and does not consider other potential impacts such as eutrophication, acidification or land use. The wide range of health and environmental impacts of products from each food group, linked for example to production methods, also needs to be considered.
Vincent’s novel approach will be supplemented by further work aiming at a more complete assessment of the impact of dietary changes.
