Many countries, even different bodies and organizations within the same country, have developed nutrient recommendations and dietary guidelines using a diversity of approaches. The process, criteria and types of evidence to support the recommendations are not clearly specified in all of the reports⁽Reference Aranceta and Pérez-Rodrigo¹⁾. Recommendations are not always aligned and controversies remain with respect to the scientific evidence, i.e. fat quality, protein requirements, dairy products or whether potatoes (excluding crisps, chips, French fries) count as vegetables. Further, while transparency and independency should be basic prerequisites for the process of developing guidelines, lobbying pressure has been a common criticism.

Ideally, the process of developing recommendations and guidelines should follow standardized protocols using explicit standards for evidence, with the strengths and limitations of the evidence explained in easy-to-understand language. Additionally, responsible bodies and organizations should plan timelines for regularly updating recommendations in light of the emerging evidence. As an example, fat consumption has decreased over the past decades in many countries, in line with recommendations, but this has not brought about the expected health outcomes. In fact, new problems have emerged: the advised decrease in fat intake may have induced unwanted dietary changes that have contributed to the increase in overweight and obesity. An adaptation of evidence ratings has been suggested that considers not only the quality of the evidence, but also the net benefit of an intervention⁽Reference Marantz, Bird and Alderman²⁾ – a perspective that also recognizes the potential for harm. Thus, the evidence assessment includes the possibility that no recommendation be made – a possibility intended to provide the appropriate level of caution in issuing guidelines.

This issue of Public Health Nutrition focuses on several studies examining different aspects of dietary recommendations and guidelines, from their development to their application. The example of developing and interpreting guidelines for protein intake, expressed as the ratio of protein to energy requirement (P:E_requirement), is described in detail in a commentary by Professor Joe Millward⁽Reference Millward³⁾. The commentary is an excellent study of how protein requirements and the P:E value for a given diet are properly interpreted, and why the P:E_requirement value might sometimes be lower than one would expect.

Also with respect to developing guidelines, Brown et al.⁽Reference Brown, Hermoso and Timotijevic⁴⁾ report on European stakeholders’ views on consumer involvement in dietary guideline development. Participation is a key principle in health promotion, and it has been argued that people have the right to participate in the planning and implementation of their health care. Since the general public is the intended end-user of dietary guidelines, members of the public, from individual lay consumers to consumer groups or consumer advocates, could potentially be involved in the process of developing guidelines. Their participation might involve providing qualitative or quantitative consumer research data, or taking part in consultations and decision-making meetings. Brown et al. find that a major benefit of involving consumers might be to increase trust in the process; but given the limited data on best practice for consumer involvement, transparency regarding their role in the process is essential.

Other articles deal with the challenge of communicating the message to consumers and encouraging the adoption and implementation of dietary guidelines. Changing icons, either a pyramid or a plate, have led to growing consumer confusion and claims in the media, including popular bloggers and social media. ‘I hated having to think about every little thing I ate in quantitative terms. People aren't machines. We're subjective and pleasure-seeking and messy and crazy… Essentially, the experience made me neurotic and anxious about food (one of my great pleasures!) without making me especially healthy’, wrote Joe Satran, blogger at The Huffington Post, in a recent post⁽Reference Satran⁵⁾.

More structured quantitative guidance and tips for everyday life can be helpful. However, such guidance should account for different population groups; should consider cultural relevance and the issues of accessibility, affordability, cooking skills and skills to make healthier choices when eating out; and should be based in common eating habits, familiar foods and prevalent food preferences. The toolkit developed by Leslie et al.⁽Reference Leslie, Comrie and Lean⁶⁾ is a good example of such guidance, while additionally addressing sustainability and encouraging home food preparation. Mithril et al.⁽Reference Mithril, Dragsted and Meyer⁷⁾ offer a different approach by developing a regional prototype diet, the New Nordic Diet (NND), which is based largely on foods originating from the Nordic region and also takes palatability, health, food culture and the environment into consideration. In a third article on implementing dietary guidelines, Probst and Tapsell⁽Reference Probst and Tapsell⁸⁾ find that, with careful food selection, meal plans with ⩾4 grain-based servings daily can meet nutrient recommendations using lacto-ovo vegetarian and rice-based cuisines, although different strategies are required for different ages and genders.

These articles assume some degree of trust in dietary recommendations. The study by Kanerva et al.⁽Reference Kanerva, Kaartinen and Ovaskainen⁹⁾ addresses a media-stirred concern in Finland that their Finnish dietary recommendations might be promoting obesity rather than preventing it. Kanerva et al. report in their study that, contrary to media claims, a diet following the Finnish nutrition recommendations, specifically one that includes high intakes of rye, vegetables, fruits and polyunsaturated fats, and moderate intakes of alcohol, saturated fats and sucrose, can help maintain a healthy weight.

In their qualitative study, Olstad et al.⁽Reference Olstad, Raine and McCargar¹⁰⁾ report on another barrier to implementing nutrition guidelines, but specifically in recreational facilities. Based on in-depth interviews conducted among food service managers in these facilities, corporate profitability was identified as a primary consideration, and thus widespread voluntary adoption of the nutrition guidelines in recreational facilities would be unlikely without government incentives or a mandate. The authors suggest appealing to an economic motive – that supporting chronic disease prevention can lead to a healthier workforce, thus improving productivity and corporate profitability. Their study calls to mind a useful heuristic proposed by Hancock⁽Reference Hancock¹¹⁾ for balancing public and private concerns. This model predicts that successful businesses will be those that cultivate all four forms of capital – human, ecological, social and economic – because they realize their success is predicated upon the health and productivity of their employees and clients, the social resources within their communities and the sustainability of the environmental resources upon which they draw. Hancock's model also serves to remind the public sector that the economic capital generated by industry constitutes the means by which society finances its human and social goals. Each sector must be mindful of the other's interests as well as constraints, such that respectful, trusting relationships are developed and maintained.

Common to all these articles is the importance of creating environments that support and facilitate the adoption of dietary guidelines by the public. This includes being based in a process that is transparent and trustworthy, providing educational tools to aid in their implementation, and encouraging trusting collaborations among stakeholders and decision makers throughout their development and implementation – government, industry and consumers together. When these are achieved, dietary guidelines might finally make sense to consumers, in a way that will encourage people to follow them.

Carmen Pérez-Rodrigo

Associate Editor

Marilyn Tseng

Editor-in-Chief