Report on the impacts of increased fish consumption on economic, health and environmental attributes
In recent years, concerns over the sustainability of food consumption patterns in high-income countries have emerged due to the now well-documented negative effects of some diets on both health and the environment. Research seeking improvements generally supports a move away from animal-based products towards plant-based products, but the role that fish and seafood might play in sustainable diets remains unclear. In particular, little is known about how promotion of fish consumption through generic advertising and other informational measures might affect the environmental and health properties of whole diets, nor whether that type of promotion would be cost-effective; that is, represent money well spent from a societal point of view.
This study analyses those questions by adapting a model of whole-diet adjustment to dietary constraints to simulate how French and Finnish consumers would change their diets if urged to raise their consumption of fish at the margin (that is, by a small amount from currently observed levels). The behavioural model, which is based on a rationality assumption and preferences estimated from observations on actual food purchases, captures the relationships of substitutability and complementarity among foods, and produces a quantitative estimate of the difficulty for consumers to modify their diets in a given way (for instance by eating more fish). The whole-diet adjustments simulated by the behavioural model are then linked to an epidemiological model to estimate health effects and a life-cycle analysis model to estimate climate effects. Monetization of the health and environmental benefits then permits the development of a cost-effectiveness analysis of the dietary change. The sustainability effects of raising consumption of fish by an arbitrarily-chosen 5% is compared to that of decreasing consumption of all meat and meat from ruminants by 5%.
The empirical results indicate that the patterns of adjustments to those exogenous changes differ between the two countries, although the broad substitutability of fish for other animal products is confirmed and, in both cases, consumers respond through complex modifications of their diets. The taste cost of increasing fish consumption, which measures the loss in hedonic rewards (taste, convenience) experienced by consumers in the short run, is small, suggesting that the barriers imposed by habits and taste/preferences to increasing fish consumption are limited. In both countries, we estimate that raising fish consumption by 5% would generate larger health benefits than either of the two meat constraints (i.e., reductions of 5% of all meat and red meat), and that most of the health improvement would results from a lower energy intake of the modified diet, suggesting that fish naturally belongs to less caloric meals. The increase in fish consumption also delivers climate benefits which, although only limited in magnitude, confirm that raising fish consumption enhances sustainability in both its health and environmental dimensions.
Placing monetary values on the environmental and health benefits, and taking into account the costs imposed on consumers, industry (for generic advertising) and the public sector (for implementing policies), we find that promoting fish consumption is cost-effective and socially desirable. That promotion should also be prioritised over measures aimed at reducing consumption of meat. Thus, rather than stigmatising meat consumers, we suggest that sustainable diet recommendations may more effectively send a more positive message urging consumers to raise their consumption of fish and seafood.