Science Spotlight

Place nutrition on the top of your grocery list

Aug. 15, 2016

Image provided by Dr. Anju Aggarwal

Food choices are primarily dictated by taste, cost, convenience, and nutritional value. These attitudes toward food also influence diet quality or the overall healthfulness of a diet. For example, perceived value of cost over nutrition has been shown to associate with lower quality diets and higher consumption of fats, added sugars, and sodium (Beydoun and Wang, 2008). However, prioritizing nutrition, without concerns of cost and convenience, tends to be a privilege of the more affluent.

Do positive food-related attitudes exist among lower socioeconomic status (SES) groups and racial/ethnic minorities? And if so, does it have any impact on their diet quality? Answers to such questions may help tailor nutrition education programs to populations at higher risk.

Dr. Anju Aggarwal, Dr. Adam Drewnowski (Public Health Sciences Division), and their team at the University of Washington's Center for Public Health Nutrition sought to answer these questions. Using national level data, they examined the importance of food-related attitudes in relation to diet quality across different population subgroups in the US. The investigators analyzed responses of close to 9,000 adults from the 2007-2010 National Health and Nutrition Examination Survey (NHANES); NHANES is a program of studies designed to assess the health and nutritional status of adults and children in the US. The results from their study were recently published in Preventive Medicine

First, the investigators set out to measure the prevalence of the importance of taste, cost, convenience, and nutrition in the US population. These perceived attitudes towards dietary choices were assessed using 4-point Likert scales (approach used to scale survey responses). Among US adults, taste was rated as "very important" (77.0%), followed by nutrition (59.9%), cost (39.9%), and convenience (29.8%).

Next, the investigators examined the role of food-related attitudes on diet quality. The Healthy Eating Index (HEI-2010), a measure of adherence to 2010 dietary guidelines, served as the diet quality measure (ranging from 0-100). Survey-weighted regressions examined associations between attitudes and HEI. The importance of nutrition, regardless of income or education, most strongly associated with HEI-2010 scores. People who attached high importance to nutrition during food shopping had HEI scores that were 8.0 points higher than those who did not. By contrast, attaching high importance to taste reduced HEI by 5.0 points. Cost and convenience had a smaller and negative impact on diet quality.

More importantly and interestingly, these associations were found to persist at all levels of income and education in the US. Those lower income and lower educated groups who prioritized nutrition during food shopping had significantly higher HEI scores than their counterparts. The investigators termed this phenomenon as nutrition resilience –  being able to achieve higher quality diets within socioeconomic constraints. Certain racial/ethnic groups also exhibited nutrition resilience, despite attaching importance to cost and convenience during food shopping.

"It is possible to eat healthy within your budget if you make it a priority", says Dr. Aggarwal, the lead author of the study. This study is the first evidence of nutrition resilience among US adults using national data. "Nutrition resilience could be one strategy to address disparities in diets in the US", Dr. Aggarwal adds.

Dr. Drewnowski, the senior author of the study says, "The next step will be to identify who eats best on a budget." Identifying food shopping behaviors, food choices and cooking practices of these resilient sub-groups is their next big question.

Funding for this study was provided by the National Institutes of Health and the Centre for Diet and Activity Research, a UK Clinical Research Collaboration Public Health Research Centre of Excellence.

Aggarwal A,Rehm CD,Monsivais P,Drewnowski A. 2016. Importance of taste, nutrition, cost and convenience in relation to diet quality Evidence of nutrition resilience among US adults using National Health and Nutrition Examination Survey (NHANES) 2007-2010. Preventative Medicine. 90: 184-192.

Beydoun MA, Wang Y. 2008. Do nutrition knowledge and beliefs modify the association of socio-economic factors and diet quality among US adults?. Preventive medicine. 46(2): 145-153.