Tablet-based nutrition app shows acceptable engagement in older adults but no diet or strength changes yet

Recruitment and retention were strong: 31 of 51 eligible participants enrolled, and 28 completed the 12-week follow-up. In the intervention group, 71.4% (10 of 14) reported using KOKU-Nut 3 or more times per week, suggesting good engagement with the technology. However, the study collected no statistically significant differences between groups in dietary intake (measured by 24-hour food diary) or physical function (grip strength and five-times sit-to-stand test) at 12 weeks, after adjusting for age and baseline values. The System Usability Scale indicated the platform was acceptable to users, and no adverse events were reported. Because this was explicitly a feasibility study rather than a powered effectiveness trial, it was sized to test recruitment, retention, and study design rather than to detect meaningful clinical changes in diet or strength.

The trial's main contribution is demonstrating that older adults can and will engage with tablet-based digital platforms: nearly 3 in 4 participants in the intervention group met the 3-times-weekly engagement target, and System Usability Scale scores were positive. Retention at 12 weeks was 90.3% (28/31), which bodes well for future studies. However, the lack of between-group differences in dietary intake or physical function after 12 weeks does not necessarily mean the app is ineffective—feasibility trials are intentionally underpowered to detect clinical outcomes. The 12-week duration may have been too short to see meaningful changes in diet quality or strength in older adults, who often require longer intervention periods and higher engagement intensity to shift health behaviors. The control group received only a leaflet (not an active comparator like a coaching program), so we cannot rule out that both groups simply did not receive enough support. A future powered randomized controlled trial with a longer follow-up period, potentially higher engagement targets, or integration with live coaching may be needed to answer whether KOKU-Nut meaningfully improves older adults' nutrition and physical function.