Future of food: Innovating towards sustainable healthy diets

Abstract

The United Nations (UN) has set out Sustainable Development Goals (SDGs) to alleviate hunger and poverty and to ensure health and wellbeing for all in a more resilient and equitable food system. The constraints and challenges are known, and all stakeholders were asked by the UN to identify and implement ‘game changing ideas’ to help achieve the SDGs. We need actions geared towards delivery of healthy, affordable, sustainable and culturally acceptable diets. New measures and metrics are being applied to industry portfolios and to local and regional diets to report on progress and inform actions. Innovation is one of the key enablers. The Decade of Action on Nutrition (2016–2025) has identified the transformation of food systems as a critical action area for reducing the risk of diet-related non-communicable diseases and for achieving the UN SDGs (WHO, 2016). The European Union and the Food and Agriculture Organization of the United Nations (FAO) have proposed transforming agri-food systems, in order to make them more inclusive, and more efficient, resilient and sustainable. The upcoming 2021 UN Food Systems Summit will provide another opportunity to identify innovative approaches for eliminating malnutrition in all its forms. The challenge is enormous. A food system consists of all the elements and activities that relate to the production, processing, distribution, preparation and consumption of food, as well as the outcome of these activities – diet, nutrition, health, economic growth, equity and environmental sustainability (HLPE, 2017). To put it quite simply, food systems link farm to fork, or farm to table. The food industry is the lynchpin connecting agricultural sector activities to consumer food choices. Food production, distribution and retail are all components of the food environment. Game-changing actions at the national level are essential for transforming food systems to meet the multiple, varied objectives embedded in the SDGs. The potential country-level approaches have been categorised into those related to availability, accessibility, affordability and desirability of actions at the national, household and individual levels (Webb et al., 2020). However, specific government actions need to be viewed in the context of multi-sector stakeholder activities and potential trade-offs among dietary, social and economic policies and programmes. For example, many multi-sector nutrition plans recommend increasing the production of nutrient-rich foods as one strategy for improving both regional and global diets. However, within each household trade-offs need to be made with respect to food acquisition or decisions taken with respect to the production, consumption and sale of crops. In Ethiopia, the government has stressed the need to produce more nutrient-rich crops. Individual producers have made it clear that diversity in the production of nutrient-rich crops will be considered only when the family's food security needs are met (Tadesse et al., 2021). Trade-offs that affect the transformation of food systems can also affect the environmental footprint of food production, often formulated in terms of greenhouse gas emissions, water withdrawals and land use. The UN SDG #12 recommends responsible agricultural practices in the production of foods. There can be a tradeoff between nutrition goals and environmental concerns, given that different staple and specialty crops have different environmental footprints. Although tree nuts and ground nuts can be part of a healthy diet, significant amounts of water are required for their production and their cost can be very different. How are policy makers to balance the environmental concerns against diet quality and cost issues in deciding which national-level strategies in agriculture and nutrition to pursue? Innovative solutions for transforming food systems must be feasible, impactful and sustainable. Some of the actions to meet these criteria will need to be context specific and adapted to local population needs. Given the complexity of food systems, it has become clear that UN agencies, national governments, the private sector, academia and civil society each have an essential role to play. There is a definite momentum for improving food systems. Some of the pathways may lead through innovation and reformulation of food products. The time to act is now! Transforming food systems requires a whole toolbox of metrics and measures. Sustainable healthy diets need to be nutrient-rich, affordable, socially acceptable and with low impact on the environment. Sustainable food systems need to be economically viable, provide value to society and make optimum use of both human and natural resources, including prudent uses of land, water and energy. The four domains of sustainability have been conceptualised as nutrition and health, economics, society and the environment. The existing literature has emphasised the links between different-type human diets and the environmental cost of food production. At this time, most sustainability-related dietary guidelines still rely narrowly on evidence drawn from the health and environmental domains. There is existing work on assessing nutrient density of foods and diets and on lifecycle analyses of food production, distribution and storage. By comparison, social and economic components of healthy diets and sustainable food systems continue to be overlooked (Nicholls & Drewnowski, 2021). Affordable nutrient density was recently highlighted by a FAO/WHO report and continues to be an issue of public health concern, especially across low- and middle-income countries (FAO et al., 2020). Much work needs to be done to establish metrics of food access and to integrate into food sustainability dialogue issues of cultural identity, gender equality and sustainable economic development. Methods to assess nutrient density of individual foods have taken many forms. Nutrient profiling models attempt to capture a food's overall nutritional value based on the relative content of nutrients and calories. Such models can include nutrients to limit (usually fat, sugar and salt) but also nutrients to encourage, such as protein, fibre and a range of vitamins and minerals (Labonté et al., 2018). Initially designed based on nutrients only, nutrient profiling models have now incorporated ingredients, such as wholegrains, dairy, fruit, and nuts and seeds. Initially intended as educational and regulatory tools, nutrient profiles have become the scientific basis for product innovation and reformulation by the food industry. The private sector, aided by the Access to Nutrition Index foundation, has been using nutrient profiling methods to review nutrient density of product portfolios. Product reformulation can take many forms, beginning with the reduction in the processed food's content of calories, fat, sugar and salt. But product reformulation can also include fortification and enrichment with vitamins and minerals, providing more affordable nutrient density for all. Product reformulation can also use a range of novel technologies, notably in the areas of sweeteners, fats and plant proteins. Nutrient density of the resulting products needs to be compared with nutrition and health standards. Nutrient profiles have also been useful in assessing the relationship between a food's nutrient density and its monetary ($) or environmental cost (GHGE). Although many cost metrics continue to be expressed per kilogram of food, kilogram is not a good measure of a food's nutritional value. There is a great deal of difference between 1 kg of sugar and 1 kg of animal source protein. Rather, cost metrics ought to be expressed per 1000 kcal, or better yet, per daily recommended amount of a nutrient of interest. In recent years, the nutrient of most interest when it comes to affordable healthy diets is high-quality protein. Diet optimisation modelling shows that various dietary strategies can be employed to reduce environmental impact, particularly greenhouse gas emissions (GHGE) (Steenson & Buttriss, 2021). Vegan diets, a step too far for many, appear to have the greatest impact on this particular measure, closely followed by dietary patterns that adhere to food-based dietary guidelines (FBDG), which describe diets that are predominantly plant-derived but contain modest amounts of nutrient-dense animal-derived foods (meat, milk, eggs and fish). Scheelbeek et al. (2020) have reported a 30% reduction in GHGE in those who adhere to the UK government's Eatwell guide compared to those with low compliance. Fuelled by interest in environmental impact, ‘plant-based’ eating has become fashionable but evidence suggests that the term means different things to different audiences. On the one hand, FBDG are already based around plants (i.e. plant-derived foods predominate), yet in a recent poll among the UK public, 61% of respondents thought a plant-based diet was a vegan (41%) or vegetarian (20%) diet (British Nutrition Foundation, 2020), which may be a perceived barrier to the adoption of healthy eating principles. The main focus of innovation in plant-based meat/milk alternatives to date has been protein, with the source of this ranging from conventional plant-derived ingredients such as pulses, nuts and grains, and protein extracts from these, to novel ingredients such as algae, insects and cultured meat. But there is more to eating healthily than decisions about protein. Protein from animal sources is not only of high quality from a nutritional perspective, containing the full set of essential amino acids, but it comes packaged with a variety of bioavailable essential micronutrients, including vitamin B12 that is not naturally present in plants. Rebalancing diets to include more and a greater variety of plant-derived ingredients and foods is likely to increase fibre intake and be good for our health and for the planet. But there are some important considerations that should determine the substitutions made, not least because animal-derived foods currently provide over a quarter of the iron in UK diets (which crucially is in a bioavailable form), almost half of the calcium, over half of the zinc, iodine and riboflavin and over a third of the vitamin A. Considerations include the following: the overall nutritional profile; the environmental impact (e.g. water footprint and land use as well as GHGE); the quality of the protein in terms of amino acid profile and digestibility; presence/absence of anti-nutritional factors such as lectins, phytate or oxalate; the need for multiple processing ingredients; and factors that contribute to acceptability such as flavour, texture and functionality, and of course cost/affordability. So, the nutritional profile and affordability of plant-derived alternatives matter, particularly for those living on low incomes or those whose diets are already relatively unhealthy. Some of the worst diets in the UK are among adolescents. Evidence indicates that the situation has worsened over the past 10 years (Buttriss, 2019; Steenson & Buttriss, 2020). Achieving diets for all that are both healthy and limit environmental impact presents complex challenges, including the need to recognise and account for trade-offs and the potential for unintended consequences (as discussed in a paper in this issue of Nutrition Bulletin by Steenson and Buttriss [2021]). It also signals the need for better integration of nutritional quality into assessments of food system impacts. Excluding or restricting animal source foods requires consideration of some important nutrients (e.g. iron, zinc, iodine, calcium and vitamin B12), in particular their bioavailability in alternative sources, highlighting the potential role of fortification to ensure future nutritional needs are met. Leveraging and combining multi-disciplinary Science & Technologies expertise in agricultural, nutritional, material and food safety sciences is a key enabler for effective food system transformation. Through food processing, agricultural raw materials are made edible, safe, nutritious, accessible and affordable. It also helps to prevent food loss or waste. Micronutrient fortification of regularly and widely consumed foods is recognised as a cost-effective way to address micronutrient deficiencies. The challenge is to innovate foods that meet at the same time the requirements for bioavailability and stability of the fortificants, while being tasty, nutritious and remaining affordable. Nestlé Research has recently studied the effect of adding more complex carbohydrates, fibre, wholegrain and protein to an iron-fortified infant cereal which had been associated with a lower risk of anaemia (Prieto-Patron et al., 2018). Adding ingredients such as pulses comes as well with an increase in anti-nutritional factors such as phytic acid which may limit the micronutrient bioavailability. Similar iron absorption was shown in a bioavailability study when comparing a product based on refined grains to an infant cereal with wholegrain and pulses that was co-fortified with iron and ascorbic acid, the most potent enhancer of iron absorption, in a molar ratio of 2:1 and had a molar ratio of phytic acid to iron below 1:1. The product composition was guided by a model predicting its glycaemic index and glycaemic load (Rytz et al., 2019). Subsequent studies in adults showed indeed that the reformulated product resulted in a better glucose and insulin response. The same multi-disciplinary scientific competences are also crucial in relation to the innovation of products offering alternatives to meat, fish and dairy that are, at the same time, tasty, nutrient dense, affordable and have a lower environmental footprint. For example, to develop a pea-based dairy alternative, agricultural scientists identified through variety selection and breeding, a pea variant with optimal intrinsic taste, yield, nutritional quality and safety properties. Food technologists and nutrition scientists worked together to reach high nutrient density (high in fibre, low in sugar, sodium and fat, and a source of calcium, vitamins D, B2, B12) and good sensory properties. Fortification with calcium helps meet the dietary requirements for this essential nutrient, while the phosphate from the tri-calcium phosphate salts used ensures the versatility of the product, in particular in hot applications (i.e. avoiding flocculation). Chicory root is contributing to a high fibre content and also bringing desirable mouthfeel. Sunflower oil provides healthy fatty acids as well as creaminess and a balanced taste profile. Pea, as a key ingredient, provides high-quality protein and a favourable environmental footprint by binding nitrogen in the soil (i.e. it is a regenerative crop). Furthermore, packaging experts developed a recyclable packaging to enlarge the contribution to environmental sustainability. Food systems offer an enormous potential for achieving most, if not all, of the SDGs. However, new challenges have emerged, which limit the ability to effectively harness the power of food systems to promote healthy diets. The transformation of food systems is complex and will require new, novel investments for success. First, the lack of high-quality metrics to inform and guide policy formulation is apparent. As noted, a toolbox of metrics must be developed that provides ways to address the nuances of healthy diets that go beyond the traditional focus of nutrition and sustainability. Issues like the economic and societal costs of healthy diets including cultural identity and gender equality need to be incorporated into our concept of healthy diets. In addition, there must be validated ways to evaluate trade-offs in achieving what may be competing goals for governments. Second, it must be emphasised that solutions need to be context specific and tailored to the specific nutrient needs and habitual eating patterns of local populations. No single planetary benchmark diet will be appropriate in all contexts. Finally, investments in research and development will be critical, including the private sector, to provide a leading role in development and reformulation of foods to promote healthy eating. Each sector has a key role to play and without a coordinated effort to include all actors, achieving a transformed food system to improve diets may indeed be elusive.