Malnutrition is a significant concern among older adults, strongly linked to altered body composition, reduced physical and mental function, and adverse clinical outcomes. While observational studies suggest that malnutrition isn't an inevitable consequence of aging, and adequate nutrition is associated with better mobility and quality of life, hospitalizations often leave insufficient time to address malnutrition during the stay itself. This necessitates a focus on post-discharge home-based treatment. Several strategies can improve dietary intake post-discharge, including Meals on Wheels (MOW), oral nutritional supplements (ONS), and nutrition therapy from a clinical nutritionist. A systematic review indicates MOW interventions improve energy intake and meal frequency, though only a few studies assessed functional outcomes. In Iceland, standard care involves MOW (one hot meal daily), but this may be insufficient for frail, nutritionally at-risk older adults. ONS offers another approach, but meta-analyses demonstrate only modest weight gain and improvements in nutritional status. This study aimed to address these limitations by combining nutrition therapy with home-delivered, energy- and protein-rich foods to ascertain if such a multi-component intervention is more effective.

Existing literature on nutritional interventions in older adults discharged from hospital shows inconsistent results. While some studies using Meals on Wheels (MOW) or oral nutritional supplements (ONS) demonstrated improvements in energy intake and/or weight gain, the effect sizes were often modest and the long-term impact unclear. Studies focusing on nutrition therapy provided by a registered dietitian showed significant improvements in body weight gain but were shorter in duration and didn't include food delivery. The evidence on the impact of such interventions on functional outcomes such as physical function and muscle strength is inconsistent, with some studies showing positive effects and others not. This lack of consistent findings highlights the need for a comprehensive intervention that combines multiple approaches to address the complex nutritional needs of older adults post-hospital discharge.

The HOMEFOOD study employed a 6-month, randomized controlled, assessor-blinded intervention trial design. 1003 potential participants were screened, with 106 (aged 66–95) meeting eligibility criteria (at risk for malnutrition using the Icelandic Nutrition Screening Tool, and discharged to independent living). Participants were randomized into intervention (n=53) and control (n=53) groups. The intervention group received individual nutrition therapy from a clinical nutritionist (five home visits and three phone calls), incorporating the principles of the Nutrition Care Process (assessment, diagnosis, intervention, monitoring, evaluation). They also received free energy- and protein-rich foods (one hot meal and two snacks daily). The control group received standard care (a booklet on nutrition and encouragement to order MOW). Assessments at baseline (hospital) and endpoint (home) included anthropometrics (weight, height, BMI, body composition via BIA, calf and midarm circumference), physical function (SPPB, walking difficulty), muscle strength (handgrip strength), dietary intake (24-hour dietary recall and food frequency questionnaire), and nutritional status (Icelandic Nutrition Screening Tool). Data analysis used independent samples t-tests/Mann–Whitney U-tests (baseline comparisons), linear mixed models (adjusted for sex for anthropometric and physical outcomes), and logistic regression (physical task performance). Intention-to-treat analysis was employed. Sample size calculations ensured sufficient power to detect significant differences in body weight and SPPB scores.

Baseline characteristics were similar between groups, except for a higher proportion of females in the intervention group. The primary outcome showed a significant mean weight gain of 1.7 kg in the intervention group (approximately 2% of body weight) and a significant mean weight loss of -3.5 kg in the control group (approximately 5% of body weight). After adjusting for sex, the intervention group had 5.1 kg higher body weight and 4.2 kg higher lean body mass at endpoint. Other anthropometric measures (BMI, waist, midarm, and calf circumference) also showed significantly better outcomes in the intervention group. The SPPB score was significantly higher in the intervention group, and they were more likely to improve in individual physical performance tasks. Handgrip strength showed no significant difference. The Icelandic Nutrition Screening Tool score indicated significantly better nutritional status in the intervention group. While baseline dietary intake was similar (~1500 kcal), the intervention group showed significant increases in energy and macronutrient intake, while the control group showed significant decreases. ONS contributed substantially (24% energy, 29% protein) to the intervention group's intake. Subgroup analysis revealed no significant effect modification by sex, marital status, or age, but weight changes differed by BMI category, with the largest gains observed in those with low or middle BMIs.

The HOMEFOOD trial demonstrates the significant benefits of a multi-component nutrition intervention in older adults after hospital discharge. The observed effects on body weight and physical function were considerably larger than those reported in studies using single intervention modalities (ONS, MOW, or dietary advice). The control group's substantial weight loss highlights the inadequacy of standard post-discharge care in preventing nutritional decline. The combined approach of personalized nutrition therapy, frequent contact with a clinical nutritionist, and readily available energy- and protein-rich foods proved highly effective in maintaining weight and improving physical function. The substantial improvement in dietary intake in the intervention group demonstrates the importance of the holistic intervention. The successful weight gain was largely attributed to increased lean body mass, suggesting that the intervention effectively countered the loss of muscle mass often observed during hospital stays. The high acceptance rate of the provided meals points towards the meal design's ability to cater to the preferences of elderly patients. The consistent findings across various subgroups indicate the intervention's broad applicability.

This study underscores the importance of proactive nutritional interventions following hospital discharge for older adults. Standard care in Iceland leads to significant weight and muscle mass loss. The six-month, multi-component intervention successfully countered these negative effects, improving weight, physical function, and nutritional status. The high effectiveness and acceptance of this intervention makes it a promising strategy to improve outcomes for elderly patients after hospital discharge. Future research could explore the cost-effectiveness of this approach and evaluate its long-term effects.

While this study had a low dropout rate and high intervention adherence, the gender imbalance between groups might affect the interpretation of results. The home-based assessment limited the scope of physical function and body composition measurements, although various methods were utilized to mitigate this limitation. The study's focus on the Icelandic context might limit the generalizability of findings to other healthcare systems.