Development of effective public health strategies is contingent upon having accurate information upon which to make decisions. The information is created through scientific research studies, however, data derived from single studies is not sufficient evidence upon which to make those decisions. It is necessary to compile data from multiple studies using systematic review approaches, which consider study similarities, differences, strengths, and limitations. The Nutrition Evidence Systematic Review team was formed to conduct nutrition- and public health-related systematic reviews and their efforts are critical in supporting the Dietary Guidelines Advisory Committees. Observations made by the team has led to a series of recommendations for the research community and they published them in the August 2022 issue of The Journal of Nutrition.
Recommendations to improve the quality of data derived from studies include the following. First, the strongest study design feasible that includes sufficient sample sizes is necessary, and all data on study groups should be published. The second recommendation is to enroll participants who reflect the diversity of a population of interest and report those characteristics including age and life stage, sex, socioeconomic status, food security, racial and ethnic background, dietary habits, health status, and country where the study was conducted. The third recommendation is that valid and reliable dietary assessment methods are used that are age and culturally appropriate to minimize measurement error. Their fourth recommendation is to describe interventions and exposures of interest and use standard definitions to promote consistency and ease of study integration into the review. The next recommendation is to use valid and reliable health outcome measures, which means avoiding self-reported outcomes and to describe the timing, setting, and methods used to ensure validity and reliability of the results. Accounting for variables that may impact the relationship between nutritional interventions or exposures and health outcomes is the sixth recommendation. Confounders, co-exposures, mediators, and effect modifiers can bias reported relationships and therefore must be measured and accounted for. The seventh recommendation is to carry out studies for a sufficient duration and include repeated measures, as appropriate to capture changes in diet throughout life, and observe the impact of diet on long-term disease processes. The final recommendation of the team was to report all relevant information needed to accurately interpret and evaluate study results. The authors conclude by stating that implementation of these recommendations would strengthen future systematic reviews leading to improved public health recommendations. They suggested implementation of the recommendations will require greater financial support by funding agencies, engagement by the research community, and acceptance by scientific journals.
Congratulations to the first author of this article, Julie Obbagy, PhD, RD, who was appointed an Editorial Board Member for The Journal of Nutrition in August 2022!
References
Julie Obbagy, Ramkripa Raghavan, Laural K English, Maureen K Spill, Charlotte L Bahnfleth, Marlana Bates, Emily Callahan, Natasha Chong Cole, Darcy Güngör, Julia H Kim, Brittany J Kingshipp, Julie E H Nevins, Sara R Scinto-Madonich, Joanne M Spahn, Sudha Venkatramanan, Eve Stoody, Strengthening Research that Answers Nutrition Questions of Public Health Importance: Leveraging the Experience of the USDA Nutrition Evidence Systematic Review Team, The Journal of Nutrition, Volume 152, Issue 8, August 2022, Pages 1823–1830, https://doi.org/10.1093/jn/nxac140.
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