The diet delusion

Posted on Mon, 12 Oct 15

Most adults think they have a good diet and adequate intake of key micronutrients such as vitamin D, despite evidence to the contrary. This discovery may help explain the failure of nutritional guidelines.

A recent three-country (Britain, Germany and North America) survey into dietary beliefs has revealed that most adults, regardless of country, felt they had an optimal diet and were adequate in both omega-3 fatty acids and vitamin D.

Most (72%) of survey respondents thought they had a ‘‘healthy’’ or ‘‘optimal’’ and more than half of the sample (52%) believed they consume all the key nutrients needed for optimal nutrition through food sources.

Poor dietary habits and omega 3 and vitamin D deficiency are widespread. For example, the total mean intake of omega-3 (EPA & DHA) in the UK is 244 mg per day, approximately half recommended intakes, while around 60% of adults are vitamin D deficient (2,3). And most people do not meet the recommended daily intakes of fruits and vegetables (4).

Commenting on the study findings, the investigators wrote, “…the consistent findings across all countries were that adults are aware of the importance of nutrition, and most adults believe their diet is optimal for health. The widespread burden of chronic diseases across all countries sampled, such as obesity, diabetes, and cardiovascular disease, does not suggest that adults are indeed consuming optimal diets as they may believe.”

“Our data serve to alert dietitians and other health professionals that consumers may have an elevated sense of the healthfulness of their own diets and may require guidance and education to achieve optimal diets.”

“Preaching about proper diet is not enough,” said one of the studies author’s Nigel Denby, RD, “Perceptions of a healthy diet and the fact that it is very difficult to consume the recommended intake of nutrients such as Omega-3 and Vitamin D via diet alone, require us to rethink that approach (5).” 

Reference: 

1. Bailey R, et al. Perceptions of a Healthy Diet: Insights From a 3-Country Survey. Nutrition Today. September 8, 2015.
2. Ian Givens D, Gibbs RA. Current intakes of EPA and DHA in European populations and the potential of animal-derived foods to increase them. Proc Nutr Soc. 2008 Aug;67(3):273-80.
3. Hyppönen E, Power C. Hypovitaminosis D in British adults at age 45 y: nationwide cohort study of dietary and lifestyle predictors. Am J Clin Nutr. 2007 Mar;85(3):860-8.
4. Food Statistics Pocketbook - in year update Department for Environment, Food and Rural Affairs.  29 May 2014
5. Survey Findings Press Release. Survey Reinforces Need for Further Understanding of Dietary Deficiencies and the Ability of Adults to Achieve Optimum Nutrition through Food Sources Alone. GNHA 2015