(PTFS09-07-23) Online Grocery Ordering System for Experimental Human Nutrition Research With High Participant Dietary Adherence

Objectives: Randomized controlled trials (RCTs) with controlled feeding are used for experimental human nutrition research. A gold standard RCT includes using a research kitchen system (RKS) to provide portioned quantities of all foods to participants. This method of food provision, while rigorous, is relatively expensive; staff-intensive; has limited geographic range; and inconsistent dietary adherence by participants. The increased availability of online grocery ordering systems (OGOS) may provide a suitable way to address these issues while continuing to support full-feeding RCT research. Our objective is to present information on subject dietary adherence and non-adherence from full-feed RCTs that provided foods using OGOS or RKS.

Methods: Data from three full-feed RCTs conducted by our research group were assessed: 1) OGOS, two-group, parallel RCT, 12-wk intervention, 49 subjects; 2) OGOS, cross-over RCT with three 3-wk interventions, 5-wk dietary washouts, 17 subjects; and 3) RKS, cross-over RCT with two 5-wk interventions, 5-wk dietary washouts, 22 subjects. For the OGOS studies, all foods were provided from grocery stores, along with instructions and kitchen equipment to store, portion, and prepare the foods. For the RKS study, portioned quantities of all foods were provided with instructions on storage and heating. For each study, subjects used menu food logs to record the amounts of protocol foods consumed each meal, and any non-protocol foods consumed. Subject-reported dietary adherence and non-adherence (cheating) were calculated as the percent of protocol foods consumed and the frequency of consuming non-protocol foods, respectively.

Results: Dietary adherence (% of protocol foods consumed, mean ± SD) was >85% for all three studies: S1: 93.4 ± 5.9%; S2: 95.3 ± 3.6%; S3: 88.0 ± 7.6%. Dietary non-adherences (occurances/wk) were: S1: 0.38 ± 0.89; S2: 0.39 ± 0.71; S3: 1.06 ± 1.90.

Conclusions: An OGOS may be used to provide protocol-specific foods with high subject dietary adherence. Online grocery ordering systems offer a suitable complement to traditional research kitchen systems to support experimental human nutrition research.

Funding Sources: Beef Checkoff, American Egg Board, Pork Checkoff, North Dakota Beef Commission, Foundation for Meat & Poultry Research & Education