To understand the susceptibility to nutrition-health misinformation related to preventing, treating, or mitigating the risk of COVID-19 during the initial lockdowns around the world, the present international web-based survey study (15 April–15 May 2020) gauged participants’ (n = 3707) level of nutrition-health misinformation discernment by presenting them with 25 statements (including unfounded or unproven claims circulated at the time), alongside the influence of information sources of varying quality on the frequency of changes in their eating behavior and the extent of misinformation held, depending on the source used for such changes. Results revealed widespread misinformation about food, eating, and health practices related to COVID-19, with the 25 statements put to participants receiving up to 43% misinformed answers (e.g., ‘It is safe to eat fruits and vegetables that have been washed with soap or diluted bleach’). Whereas higher quality information sources (nutrition scientists, nutrition professionals) had the biggest influence on eating behavior change, we found greater misinformation susceptibility when relying on poor quality sources for changing diet. Appropriate discernment of misinformation was weakest amongst participants who more frequently changed their eating behavior because of information from poor quality sources, suggesting disparities in the health risks/safety of the changes performed.

Nutrition messages are a central part of policy making as well as communication via product information, advertising, healthcare advice and lifestyle campaigns. However, with amplified information (and misinformation) from a growing number of sources, inconsistent and conflicting food landscapes, and limited engagement from the public, nutrition messaging tensions have become more accentuated than previously. In this review, we focus on the challenges facing those wishing to effect dietary change through communication; and identify opportunities and future research questions. Beginning with a new working definition and taxonomy for the term ‘nutrition message’, we consider the evolution of public health nutrition messages from the past century and discuss which types of messages may be more effective. We then turn to the challenges of implementation and highlight specific barriers to recipients' understanding and change. While the evidence has many gaps and there is a need for systematic evaluation of nutrition messages, research indicates that recipients are more likely to act on fewer messages that provide clear benefits and which resonate with their perceived health needs, and which are relatively straightforward to implement. Effectiveness may be improved through consideration of how nutrition messages can be designed to complement key non-health drivers of food choice (taste, cost) and societal/cultural norms. Consistency can be achieved by aligning the wider food and messaging environment to desired public health actions; that is by ensuring that retail settings provide and signpost healthier choices, and that mass media nutrition messages work with, not against, public health advice.