Systematic review and meta-analysis of remotely delivered interventions using self-monitoring or tailored feedback to change dietary behavior

Abstract

Background: Self-monitoring (SM) of diet and tailored feedback (TF) have been suggested as tools for changing dietary behavior. New technologies allow users to monitor behavior remotely, potentially improving reach, adherence, and outcomes.

Objective: We conducted a systematic literature review and meta-analysis to address the following question: are remotely delivered standalone (i.e., no human contact) interventions that use SM or TF effective in changing eating behaviors?

Design: Five databases were searched in October 2016 (updated in September 2017). Only randomized controlled trials published after 1990 were included. Trials could include any adult population with no history of disordered eating which delivered an SM or TF intervention without direct contact and recorded actual dietary consumption as an outcome. Three assessors independently screened the search results. Two reviewers extracted the study characteristics, intervention details, and outcomes, and assessed risk of bias using the Cochrane tool. Results were converted to standardized mean differences and incorporated into a 3-level (individuals and outcomes nested in studies) random effects meta-analysis.

Results: Twenty-six studies containing 21,262 participants were identified. The majority of the studies were judged to be unclear or at high risk of bias. The meta-analysis showed dietary improvement in the intervention group compared to the control group with a standardized mean difference of 0.17 (95% CI: 0.10, 0.24; P < 0.0001). The I2 statistic for the meta-analysis was 0.77, indicating substantial heterogeneity in results. A "one study removed" sensitivity analysis showed that no single study excessively influenced the results.

Conclusions: Standalone interventions containing self-regulatory methods have a small but significant effect on dietary behavior, and integrating these elements could be important in future interventions. However, there was substantial variation in study results that could not be explained by the characteristics we explored, and there were risk-of-bias concerns with the majority of studies.

FIGURE 1

Study selection. RCT, randomized controlled trial.

FIGURE 2

Bias assessment using the Cochrane assessment of bias tool.

FIGURE 3

Forest plot of the 51 dietary outcomes nested in 23 studies included in the meta-analysis. Fat scores or points are as described in Brug et al., 1998 (28): “The fat score that ranges between 12 and 60 is the result of a short [FFQ] in which the frequency of use and portion size of the 12 main fat sources in the Dutch diet are assessed”; Campbell et al., 1994 (29): “Dietary fat and saturated fat scores were obtained by multiplying frequency of consumption (calculated as servings per day) by portion data for each item and summing the items”; Campbell et al., 1999 (30): “Dietary fat scores were obtained by multiplying frequency of consumption adjusted to daily intake (3, 2, 1, 0.5, 0.14, 0.07 and 0) by fat content per serving of each item and summing items”; Gans et al., 2009 (31): “The FHQ fat summary score was calculated by taking the mean of all behavioral FHQ questions … response categories for the behavioral questions were: 0 = almost always, 1 = often, 2 = sometimes, 3 = rarely, and 4 = never”; Oenema et al., 2005 (39): “Answers to the [FFQ] items were converted into a fat score ranging from 0 to 80, reflecting total saturated fat intake”; Springvloet et al., 2015 (42, 43): “Saturated fat intake was measured with [an FFQ] … Based on this questionnaire, fat points were calculated … The total ‘fat score’ was based on 35 … food products [to which] … fat points were assigned for each product group, ranging from zero … –5 (…summed up to create a total fat points measure).” EDNP, energy dense, nutrient poor; FFQ, food-frequency questionnaire; FHQ, food habits questionnaire; Sat, saturated; serv, servings; SSB, sugar-sweetened beverage; Veg, vegetables; %kcal, percentage of total.