Effectiveness of dietary interventions delivered by digital health to adults with chronic conditions: Systematic review and meta-analysis

BACKGROUND

Digital health interventions may facilitate management of chronic conditions; however, no reviews have systematically assessed the effectiveness of dietary interventions delivered by digital health platforms for improving dietary intake and clinical outcomes for adults with diet-related chronic conditions.

METHODS

Databases CINAHL, CENTRAL, Embase and MEDLINE were searched from inception to April 2021 to identify controlled trials for dietary education delivered by digital health (mobile or electronic health) to adults with diet-related chronic conditions. Random effects analysis was performed for diet quality, food groups, nutrients and clinical outcomes. Screening, data extraction and quality checking were completed in duplicate.

RESULTS

Thirty-nine studies were included involving 7333 participants. Significant changes were found for Mediterranean diet adherence score (standardised mean difference [SMD] = 0.79; 95% confidence interval [CI] = 0.18 to 1.40), overall fruit and vegetable intake (mean difference [MD]: 0.63 serves/day; 95% CI = 0.27-0.98), fruit intake alone (MD = 0.58 serves/day; 95% CI = 0.39 to 0.77) and sodium intake (SMD = -0.22; 95% CI = -0.44 to -0.01). Improvements were also found for waist circumference [MD = -2.24 centimetres; 95% CI = -4.14 to -0.33], body weight (MD = -1.94 kg; 95% CI = -2.63 to -1.24) and haemoglobin A1c (MD = -0.17%; 95% CI = -0.29 to -0.04). Validity of digital assessment tools to measure dietary intake were not reported. The quality of evidence was considered to have low to moderate certainty.

CONCLUSIONS

Modest improvements in diet and clinical outcomes may result from intervention via digital health for those with diet-related chronic conditions. However, additional robust trials with better reporting of digital dietary assessment tools are needed to support implementation within clinical practice.

Dietary Education Delivered by Digital Health for Improving Dietary Intake and Clinical Outcomes in Chronic Conditions: A Systematic Review and Meta-Analysis

Objectives

To determine the effectiveness of dietary education delivered by digital health interventions for improving dietary intake and clinical outcomes in chronic conditions.

Methods

CINAHL, Cochrane CENTRAL, Embase and MEDLINE databases were systematically searched. Controlled trials involving dietary education delivered via digital health interventions (mobile or electronic health technology) to adults with chronic conditions were included. The dietary intervention component must have been developed or delivered by health professionals, or in line with best practice guidelines. Data was meta-analyzed by a random effects model for diet quality, fruit and vegetable consumption, dietary intake of fat, sodium, protein, fibre and energy, and various clinical outcomes. Screening, data extraction and quality assessment were completed in duplicate.

Results

Thirty-eight studies compromising 7,303 participants met the inclusion criteria. Digital health interventions included: mobile phone apps and messaging systems (n = 16), internet-based (n = 16), electronic software (n = 1) or a combination of these methods (n = 5). Studies showed digital health was effective at improving Mediterranean diet adherence score [standardized mean difference: 0.79; 95% confidence interval (CI): 0.18, 1.40] and overall fruit and vegetable intake [mean difference (MD): 0.58 serves per day; 95% CI: 0.01, 1.14]. However, no significant effects were found for other measures of diet quality, single food group intake, nutrients and energy intake. Digital health interventions significantly reduced waist circumference [MD: −2.34 cm; 95% CI: −4.29, −0.38cm), body weight [MD: −1.88; 95% CI: −2.60, −1.16 kg) and hemoglobin A1c levels [MD: −0.18%; 95% CI: −0.30, −0.05%). Overall the studies were rated as poor quality.

Conclusions

Dietary education delivered via digital health interventions significantly improved Mediterranean diet adherence, overall fruit and vegetable intake, waist circumference, weight and hemoglobin A1c levels. However, given the relatively poor quality of the studies, additional robust trials are needed to the guide implementation and scale-up of these interventions in health services.

Funding Sources

None.

Concentration Effects on the Thermophoresis of Aerosol Spheres

The thermophoretic motion of a homogeneous suspension of identical spherical particles of arbitrary thermal conductivity and surface properties is considered under conditions of small Knudsen, Peclet, and Reynolds numbers. The effects of interaction of the individual particles are taken into explicit account by employing a unit cell model which is known to provide good predictions for the sedimentation of monodisperse suspensions of spherical particles. The appropriate equations of conservation of energy and momentum are solved for each cell, in which a spherical particle is envisaged to be surrounded by a concentric shell of suspending fluid, and the thermophoretic migration velocity of the particle is calculated for various cases. Analytical expressions of this mean particle velocity are obtained in closed form as functions of the volume fraction of the particles. Comparisons between the ensemble-averaged thermophoretic velocity of a test particle in a dilute suspension and our cell-model results are made. A parallel analysis for the sedimentation of aerosol spheres is also presented. Copyright 1999 Academic Press.