A Mobile Intervention Designed Specifically for Older Adults With Frailty to Support Healthy Eating: Pilot Randomized Controlled Trial

BACKGROUND: Frailty, a common geriatric syndrome, predisposes older adults to functional decline. No medications can alter frailty's trajectory, but nutritional interventions may aid in supporting independence. OBJECTIVE: This paper presents a pilot randomized controlled trial to investigate the feasibility and efficacy of a mobile health intervention, “Olitor,” designed to enhance adherence to the Mediterranean diet among older adults with frailty, requiring no external assistance. METHODS: The study sample consisted of 15 participants aged 66-77 (mean 70.5, SD 3.96) years randomized into intervention (n=8; 8 females; mean 72.4, SD 4.8 years) and control groups (n=7; 6 females, 1 male; mean 70.0, SD 3.9 years). The intervention involved a patient-facing mobile app called “Olitor” and a secure web-based administrative dashboard. Participants were instructed to use the app at least weekly for 3 months, which provided feedback on their food choices, personalized recipe recommendations, and an in-app messaging feature. Using Mann-Whitney tests to compare change scores and Hedges g statistics to estimate effect sizes, the primary efficacy outcomes were adherence to the Mediterranean diet score and insulin resistance measures. Secondary outcomes included retention as a measure of feasibility, engagement level and user app quality ratings for acceptability, and additional metrics to evaluate efficacy. Models were adjusted for multiple comparisons. RESULTS: The findings demonstrated a significant improvement in the Mediterranean diet adherence score in the intervention group compared to the control (W=50.5; adjusted P=.04) with median change scores of 2 (IQR 2-4.25) and 0 (IQR –0.50 to 0.50), respectively. There was a small and insignificant reduction in homeostasis model assessment of insulin resistance measure (W=23; adjusted P=.85). Additionally, there were significant increases in legume intake (W=54; adjusted P<.01). The intervention's effect size was large for several outcomes, such as Mediterranean diet adherence (Hedges g=1.58; 95% CI 0.34-2.67) and vegetable intake (Hedges g=1.14; 95% CI 0.08-2.21). The retention rate was 100%. The app's overall quality rating was favorable with an average interaction time of 12 minutes weekly. CONCLUSIONS: This pilot study revealed the potential of the mobile intervention “Olitor” in promoting healthier eating habits among older adults with frailty. It demonstrated high retention rates, significant improvement in adherence to the Mediterranean diet, and increased intake of recommended foods. Insulin resistance showed a minor nonsignificant improvement. Several secondary outcomes, such as lower extremity function and Mediterranean diet knowledge, had a large effect size. Although the app's behavior change features were similar to those of previous digital interventions, the distinctive focus on theory-informed mechanistic measures involved in behavioral change, such as self-regulation, self-efficacy, and expected negative outcomes, may have enhanced its potential. Further investigations in a more diverse and representative population, focusing on individuals with impaired insulin sensitivity, are warranted to validate these preliminary findings. TRIAL REGISTRATION: ClinicalTrials.gov NCT05236712; https://clinicaltrials.gov/study/NCT05236712