Studies that aim to identify knowledge and attitudes towards specific macronutrients, such as protein, lack validated instruments.8-13, 15 Currently, no validated questionnaires exist that attempt to measure the knowledge and attitude constructs of protein among the college student population.9 Therefore, the aim of this study was to develop a questionnaire to measure protein knowledge and attitudes, as well as to provide preliminary evidence of knowledge construct validity and explore the dimensionality of the attitude constructs, in the DPAQ.
The EFA identified a multidimensional structure and the original 14 attitude items could be shortened by five items without decreasing internal reliability. Five items loaded strongly with human/environmental health (Factor 1). Items contributing positively to the Factor 1 score include ‘meat production is harmful to the environment,’ ‘meat should not be consumed,’ and ‘the impact of climate change can be reduced by consuming less meat, dairy products, and eggs.’ Items contributing negatively include ‘meat consumption is unhealthy’ and ‘egg consumption is harmful to human health.’ The inverse contributions of the items ‘meat consumption is unhealthy’ and ‘meat should not be consumed’ to the overall Factor 1 score may provide evidence that college students’ do not consider health when determining food items that should and should not be consumed.
Two items loaded strongly with organic sources (Factor 2), which suggests that college students agree organic protein sources are healthier and better for the environment. Although the exact extent is unknown, this shows that college students place some value on organic protein sources. Two items also loaded strongly with protein RDA (Factor 3), which shows that college students believe the RDA for protein is adequate in terms of healthy weight loss and people adhering to a vegetarian diet. The factor structure provides evidence that attitude constructs towards protein are multidimensional.
Future development of the DPAQ should further develop the attitude constructs. An analysis of the relationship between nutrition information sources and the attitude constructs would be beneficial to identify strategies to educate college students. Adding more items related to Factor 2 and 3 may help define the factors and may strengthen the correlations observed among the protein attitudes measured.
The factors displayed adequate reliability;14 and good internal reliability was observed among Factor 1 and 2. Factor 3 displayed satisfactory internal reliability. Future development should include increasing internal reliability, such as using more clear and concise wording to assess attitudes towards the protein RDA. Temporal reliability remains unexplored.
The significant difference in mean test scores between the undergraduate nutrition and non-nutrition (education) students indicated that the DPAQ instrument had adequate construct validity. The nutrition students’ mean test score was greater than the non-nutrition students, which has been observed in previous studies.15-19 The mean test score of nutrition students in the current study was lower than those in previous studies, which may be due to many factors, such as administering the questionnaire without prior notice or wording of knowledge statements.10-13 It is important to note the instruments used in previous studies had content not exclusively on protein, but included content related to general nutrition and salt knowledge among adult and student populations.9-13
While studies have shown dietary pattern can be influenced by eating motives and the perceived impacts on human health and the environment, more research is needed.9-13, 20 With further development, the DPAQ may be used to identify knowledge and attitudes towards protein on the topics of human/environmental health, organic sources, and adequacy of the RDA, as well as other topics needed to capture the full nature of protein attitudes.
Due to increased popularity of social media platforms, there has been a commensurate rise in the amount of false nutrition information presented to the general public.21-23 The lack of “media literacy” may contribute to this wide range of false information. Therefore, it is necessary to create validated instruments to assess protein attitudes and knowledge among the general public. Identifying protein knowledge and attitudes will facilitate the design and development of education tools to increase awareness and decrease misconceptions currently associated with protein. Interventions targeting various factors, such as eating motives and reliable nutrition sources, may also lead to improved understanding of evidence-based protein intake.
The strengths of this study include sample sizes, internal consistency of items, and utilizing the evidence-based approach for questionnaire development; however, several limitations exist. Although participants were homogenous in gender, age, and race, results may not be generalizable to other populations. It is important to examine validity in a more diverse population before conducting broader population studies. Just like any self-reported item, this study is also limited by the truthfulness of participants. Satisfactory internal consistency (α < 0.70) was identified for Factor 3, which may provide evidence of inconsistent answers to attitude questions regarding protein RDA.14 Future studies should focus on increasing internal reliability of the DPAQ by adjusting the number of items, rewording questions, and reformatting the instrument. The instrument’s validity should be examined in a more diverse population, as well as provide more complex measurements to explore the attitude constructs multidimensionality.