Innovative plant protein fibre and physical activity solutions to address poor appetite and prevent undernutrition in older adults


Older adults with poor appetite are at high risk of undernutrition due to the role of appetite as key driver of food intake. Although a negative impact on health is known, there is currently a lack of effective strategies to prevent undernutrition. Dietary protein and fibre are critical nutrients in this population, and enhancing their intake is vital to preventing undernutrition and maintaining organ function and health.

Objective and approach:

In APPETITE, a transdisciplinary consortium of experienced and well-connected experts from eight institutions in six European countries will collaborate to enhance protein and fibre consumption of community-dwelling older dults with poor appetite and overcome undernutrition through targeted nutrition and physical activity. 

In a translational approach – from development of innovative food products in cooperation with consumers, to testing of these products at experimental level to clinical application using harmonised methodologies in shared samples – we will combine high-level developmental, metabolic and clinical research. 


Older adults with poor appetite will first be carefully characterized, and their nutritional and behavioral preferences evaluated in a mixed-methods approach.

Innovative, affordable, easily and widely applicable products will be developed for and together with older adults with poor appetite by combining several domestic plant proteins and dietary fibres. 

Mechanistic insights will be gained by examining the impact of selected products, physical activity and probiotic interventions on digestibility, amino acid bioavailability and whole-body protein metabolism. 

In a multi-country randomized controlled intervention trial, the impact of two new food products as part of a personalised optimized diet, a physical activity programme, and their combination will be determined regarding appetite, dietary intake, nutritional status, anabolic response, metabolic parameters and physiological function. 

A wide range of dissemination activities will raise awareness, share knowledge, and improve dialogue between consumers, scientists, healthcare professionals, food industry and health policy.


APPETITE will improve our understanding about plant-based protein and fibre products and their metabolic and clinical effects. It will create new knowledge how these products in a whole-diet approach together with physical activity and regular social contacts, may contribute to overcome undernutrition. Results will be incorporated in recommendations and guidelines, strengthen European agri-food industry, and inform policy to finally contribute to a better quality of life of older Europeans.


Partner Organization Partner Country
University College Dublin (UCD) Ireland
Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) France
Fraunhofer Institute for Process Engineering and Packaging (IVV) Germany
Newcastle University (NU) United Kingdom
University of Padua (UNIPD) Italy
Vrije Universiteit Amsterdam (VU) Netherlands
Food Companions BV, Bridge2Food Netherlands



  • In APPETITE, older adults with poor appetite were carefully characterized in a secondary analysis of data from the Longitudinal Aging Study Amsterdam (LASA). Out of 28 variables from six domains – general, physiological, emotional, cognitive, social, and lifestyle – female sex, chewing problems, unintended weight loss, polypharmacy and depressive symptoms were associated with poor appetite.
  • Semi-structured qualitative interviews with older adults across the UK highlighted the complex array of factors that impact on appetite and the differences in their individual journeys to poor appetite. Comments on using a nutrient powder to fortify foods were positive overall with the desire for natural ingredients, safety and approval by trusted experts. 
  • Innovative plant protein fibre (PPF) products were developed by Fraunhofer IVV (DE) together with all project partners and older adults with poor appetite. Sensory properties and acceptance of six PPF products with the targeted amino acid profile and acceptable taste according to the researchers were examined by older adults at two research sites (UCD, Dublin and FAU, Nuremberg).
  • Based on liking, three PPF products were selected for the examination of amino acid bioavailability in six Irish and five Italian volunteers aged 65 years or older. Two PPF products were finally selected for the human multicenter intervention study, wherein metabolic effects – utilisation of plant proteins in comparison to animal protein – and clinical effects of the innovative plant protein fibre products will be examined as part of a personalised optimized diet in combination with a physical activity programme. 
  • In APPETITE, a range of dissemination activities are raising awareness, sharing knowledge, and improving dialogue between relevant stakeholders, for example, a project website was created (, and first project results were presented in scientific symposia at the annual congress of the European Society for Clinical Nutrition and Metabolism (ESPEN) in Vienna and the European Geriatric Medicine Society (EuGMS) in London in September 2022.


Title: Innovative plAnt Protein fibre and Physical activity solutions to address poor appEtite and prevenT undernutrITion in oldEr adults –APPETITE
Author: Dorothee Volkert*, Clare A. Corish*, Dominique Dardevet*, Giuseppe De Vito*, Christelle Guillet*, Stephanie Bader-Mittermaier*, Sian Robinson*, Helen M. Roche*, Avan A. Sayer*, Marjolein Visser*


Project number:
Duration: 100%
Duration: 100 %
Related funding round:
Project lead and secretary:
Dorothee Volkert
Responsible organisation:
Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute for Biomedicine of Aging, Germany