Liking and acceptability of whole grains increases with a six-week exposure but preferences for foods varying in taste and fat content are not altered: a randomized controlled trial

Authors: De Leon, Angela; BURNETT, DUSTIN - University Of California, Davis; Rust, Bret; Casperson, Shanon; Horn, William; Keim, Nancy

Submitted to: Current Developments in Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2020
Publication Date: 3/9/2020
Citation: De Leon, A., Burnett, D.J., Rust, B.M., Casperson, S.L., Horn, W.F., Keim, N.L. 2020. Liking and acceptability of whole grains increases with a six-week exposure but preferences for foods varying in taste and fat content are not altered: a randomized controlled trial. Current Developments in Nutrition. 4(3). https://doi.org/10.1093/cdn/nzaa023.
DOI: https://doi.org/10.1093/cdn/nzaa023

Interpretive Summary: An important recommendation in the Dietary Guidelines for Americans is that more whole grain products be consumed; these foods contribute important nutrients like dietary fiber, some minerals, and other bioactive components that may be reduced after grains are refined. However very few American adults achieve the recommended levels of whole grains in their diets and objectionable taste is often considered one reason for the unpopularity of these foods. We conducted a study to determine if consumer preferences for grain products were related to taste of grain products themselves or other dimensions of taste related to fat content or sweetness/savoriness of foods. We found that by providing weekly market baskets of whole grain products, consumers increased intake of whole grains compared to their reported pre-study amounts. After 6 weeks of increased whole grain consumption, improved ratings of liking, flavor, texture were recorded, but no changes were noted in liking or wanting of high-fat/low-fat foods that were sweet or savory. Our results suggest that liking or taste did not present a barrier to consuming whole grain products when such products are provided in the context of an intervention study.

Technical Abstract: Background: Since 2005, the Dietary Guidelines for Americans recommend consuming at least half of total grains as whole grains (WG) for optimal health benefits; however, consumption of WG falls far short of recommended amounts. Objective: This study aimed to evaluate the effect of mere exposure to WG on liking, acceptability, and consumption of WG foods and to determine if exposure to WG would influence liking and wanting for other foods varying in fat content and sweet taste. Design: Healthy, self-identified low whole grain consumers (n=45) were randomized to either a 6-week WG intervention or a refined grain (RG) control condition during which they received a weekly market basket of grain products to incorporate into daily meals and snacks. Consumption of grain products was measured by weekly logs and weigh-backs. A sensory evaluation protocol was conducted at baseline and week 6 to evaluate changes in perception of grain products. Computer tasks designed to measure liking and wanting for other foods varying in high/low-fat content and sweet/savory taste were also completed at baseline and week 6. Results: Participants in the WG group significantly increased WG consumption. Exposure to WG products resulted in improved ratings of liking, flavor, texture, and willingness to include WG in the regular diet. No significant changes in liking or wanting for foods representing high-fat sweet (HFSW), low-fat sweet (LFSW), high-fat savory (HFSA), or low-fat savory (LFSA) categories were found in the WG group. In contrast, exposure to RG foods resulted in an increased explicit wanting for HFSW and LFSW and a decreased wanting for HFSA foods. Conclusions: Mere exposure to WG foods represents a feasible and easily applied behavioral strategy for increasing consumption of WG. Encouraging consumers to focus on enjoyment of the taste may be more effective than emphasizing the health benefits of WG consumption.