Plant protein, fibre and physical activity solutions to address poor appetite and prevent undernutrition in older adults: study protocol for the APPETITE randomised controlled trial.

Reduced appetite with ageing is a key factor that may increase risk of undernutrition. The objective of this study is to determine the impact of innovative plant protein fibre (PPF) products within a personalised optimised diet (PD), a physical activity (PA) programme, and their combination on appetite, and other nutritional, functional and clinical outcomes in community-dwelling older adults in a multi-country randomised controlled intervention trial. One hundred and eighty community-dwelling adults (approximately sixty per trial centre in Germany, Ireland and Italy) aged 65 years and over will be recruited to participate in a 12-week, parallel-group, controlled trial. Participants will be randomised into one of four groups: 1, PD (incorporating two PPF products): 2, PA; 3, PD + PA; and 4, no intervention (control). The primary outcome is appetite measured by visual analogue scales and energy intake from an ad libitum test meal. Secondary outcomes include fasting and postprandial appetite-related gut hormones, Simplified Nutritional Appetite Questionnaire score, body composition, cardiorespiratory fitness, muscle strength, physical function and PA. In addition, self-efficacy, cognitive status, dietary restraint, depressive symptoms and compliance and acceptability of the intervention will be assessed. Metabolomic profiles, RMR, muscle motor unit properties and gut microbiome will also be assessed to explore potential underlying mechanisms. This multi-centre randomised controlled trial will advance knowledge on how PD (incorporating PPF products), PA and their combination influence appetite, nutritional status and related health outcomes in community-dwelling older adults and contribute to the prevention of undernutrition. Trial registration: Clinical Trials.gov Registry NCT05608707 (registered on 2 November 2022). Protocol Version: NCT05608707 Version 4 (registered on 29 September 2023).

Dietary characteristics of community-dwelling older adults with poor appetite: a cross-sectional analysis.

RATIONALE: Poor appetite is considered a key factor in the development of malnutrition, a link that can be explained by alterations in dietary intake. Given the limited data on dietary characteristics in community-dwelling older adults with poor appetite, the present study aimed to examine whether poor appetite is associated with lower nutrient intake and more unfavourable food choices. METHODS: In 569 participants of the Longitudinal Aging Study Amsterdam aged ≥70 years appetite was assessed using the Simplified Nutritional Appetite Questionnaire and dichotomised into normal (>14) and poor (≤14). Intake of energy, 19 nutrients, 15 food groups, the Dutch Healthy Diet Index 2015 (DHD15) and Mediterranean Diet Score (MDS) were calculated from a food frequency questionnaire. Dietary differences between appetite groups were examined using Mann-Whitney U test and binary logistic regression adjusted for potential confounders. RESULTS: Mean age was 78 ± 6 years and 52% were female. Appetite was poor in 12.5% of participants. Energy intake was 1951 (median; quartiles 1-3: 1,653-2,384) kcal/day with no difference between appetite groups. Poor appetite was associated with lower intake of protein (OR 0.948, 95%CI 0.922-0.973), folate (0.981, 0.973-0.989), zinc (0.619, 0.454-0.846), vegetables (0.988, 0.982-0.994) and lower scores of DHD15 (0.964, 0.945-0.983) and MDS (0.904, 0.850-0.961), as well as higher intake of carbohydrates (1.015, 1.006-1.023), and vitamins B2 (4.577, 1.650-12.694) and C (1.013, 1.005-1.021). CONCLUSIONS: Community-dwelling older adults with poor appetite showed poorer diet quality with a lower intake of protein, folate, zinc and vegetables, compared with those reporting normal appetite and should be advised accordingly.

Characterisation of community-dwelling older adults with poor appetite.

PURPOSE: A poor appetite affects up to 27% of community-dwelling older adults in Europe and is an early predictor of malnutrition. Little is known about the factors associated with poor appetite. The present study, therefore, aims to characterise older adults with poor appetite. METHODS: As part of the European JPI project APPETITE, data from 850 participants, aged ≥ 70 years of the Longitudinal Ageing Study Amsterdam (LASA) from 2015/16 were analysed. Appetite during the last week was assessed with a five-point scale and dichotomised into "normal" and "poor". Binary logistic regression was used to examine associations between 25 characteristics from 5 domains-physiological, emotional, cognitive, social, and lifestyle-and appetite. First, domain-specific models were calculated using stepwise backward selection. Second, all variables contributing to poor appetite were combined in a multi-domain model. RESULTS: The prevalence of self-reported poor appetite was 15.6%. Fourteen parameters from all five single-domain models contributed to poor appetite and were entered into the multi-domain model. Here, female sex (total prevalence: 56.1%, odds ratio: 1.95 [95% confidence interval 1.10-3.44]), self-reported chewing problems (2.4%, 5.69 [1.88-17.20]), any unintended weight loss in the last 6 months (6.7%, 3.07 [1.36-6.94]), polypharmacy defined as ≥ 5 medications in the past 2 weeks (38.4%, 1.87 [1.04-3.39]), and depressive symptoms (Centre for Epidemiologic Studies Depression Scale without appetite item) (1.12 [1.04-1.21]) were associated with an increased likelihood of having poor appetite. CONCLUSION: According to this analysis, older people with the characteristics described above are more likely to have a poor appetite.