APPETITE: Plant Protein and Exercise Solutions for the Prevention of Undernutrition in Older Adults.

Innovative plAnt Protein Fibre and Physical Activity Solutions to Address Poor appEtite and prevenT undernutrITion in oldEr Adults (APPETITE)

Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement, Friedrich-Alexander-Universität Erlangen-Nürnberg, University of Padova

The APPETITE Trial aims to investigate the efficacy of innovative plant protein fibre (PPF) products (developed in a previous workpackage) as part of a personalised diet with/out physical activity on appetite and incidence of undernutrition in older persons from three European countries at high risk of undernutrition.

It is normal that dietary intake decreases as we age due to reduced activity and muscle mass. However, appetite is a key determinant of dietary intake, and poor appetite can result in undernutrition. In many instances, older adults do not recognise their appetite has decreased significantly as the decline is slow and progressive. Protein and fibre are often poorly consumed in the diets of older adults with decreased appetite, but essential for health and well-being. Interventions designed to increase appetite, or increase dietary intake despite a reduced appetite, should therefore be key to preventing undernutrition (i.e. protein-energy malnutrition as well as nutrient deficiencies). However, treatment strategies for poor appetite are not well-established. In this multi-centre randomised controlled trial conducted in Ireland, Germany, and Italy, a two-by-two factorial design will define the individual and combined impact of two intervention conditions over 12 weeks: 1) personalised diet with focus on plant-based protein plus fibre; and 2) physical activity. At each centre, 60 older adults (180 in total) will be randomly allocated to one of the following four groups over a 12 week period: 1) personalised diet plus physical activity program (PD + PA), 2) usual diet plus physical activity (PA), 3) personalised diet and no PA (PD), and 4) control (usual diet, no PA). Using identical procedures, two testing visits will be completed before and after the 12 intervention or control period.

Randomised controlled trial, a two-by-two factorial design will define the individual and combined impact of two intervention conditions over 12 weeks

A personalised diet intervention involving the incorporation of the developed plant-based protein and fibre product. Participants will also undertake 2 weekly group exercise sessions incorporating strength and balance exercises, along with home-based exercise

Participants will consume their usual diet and undertake 2 weekly group exercise sessions incorporating strength and balance exercises, along with home-based exercise

A personalised diet intervention involving the incorporation of the developed plant-based protein and fibre product.

This arm will not be given any nutritional or physical activity support. They will be instructed to carry on with their usual activities.

The 12 week intervention will involve 2 weekly group exercise sessions incorporating strength and balance exercises, along with home-based exercise focused on increasing time spent walking.

Two Plant-based Protein and Fibre (PPF) product products have been selected from six initially developed, with best amino acid blend, taste, and bioavailability. Participants will be provided with the PPFs to consume daily as part of a personalised diet over 12 weeks.

12-week change in appetite to be assessed by Visual Analogue Scale (VAS) during a test meal challenge. The VAS is a validated tool for assessing subjective sensations such as hunger, fullness and desire to eat. On each 100-mm line, an appetite (hunger, fullness, desire to eat) sensation was paired with the opposing sensation (for example, 'hungry' and 'not hungry').

12-week change in physical activity score will be assessed using 7-day accelerometery data. This is a validated device that is installed onto an individuals thigh for continuous readings. The data generated describes the amount of time spent engaging in physical activities and sedentary activities, and gives an output score in MET.h (Metabolic EquivalenT hour). This is a measure of energy usage over and above what is required at rest, where 1MET is equivalent to oxygen uptake of 3.5ml/kg body weight/minute

To be assessed at baseline, prior to commencing the intervention, and during week 12 of the intervention or control period

12-week change in physical function will be assessed using the Short Physical Activity Battery (SPPB)

12-week changes in perceived quality of life will be assessed using the EuroQol (European Quality Of Life) questionnaire (EQ-5D-5L). This consists of self-assessed rating of health under 5 dimensions (Mobility, Self-Care, Usual Activity, Pain/Discomfort, Anxiety/Depression), and perceived overall health on a magnitude scale (0-100) anchored with opposing statements (0= the worst health you can imagine; 100= the best health you can imagine).

12-week change in dietary restraint will be assessed using the Cognitive Dietary Restraint (CDR) subscale of the Three Factor Eating Questionnaire (TFEQ). The questionnaire consists of a subscale of 6 questions relating to cognitive dietary restraint from the orignal 50 item questionnaire. The questions are a mix of 'true/false', and likert scale type answers.

12-week change in energy, protein and fibre intake assessed using a three-day non-weighed dietary record

12-week change in appetite-related gut hormone response to a fixed meal. Assessed in circulating peripheral bloods at fasting, and at regular intervals postprandially (minute 30, 60, 90, 120, 150, & 180).

12-week change in fasting peripheral blood profile (insulin, leptin, glucose, amino acid, fatty acid)

Body composition will be assessed by BIA across all sites at baseline and post intervention. BIA is a quick non-invasive method of measuring body composition. Bioelectrical impedance analysis (BIA) measures body composition based on the rate at which an electrical current travels through the body. Body fat (adipose tissue) causes greater resistance (impedance) than lean mass and slows the rate at which the current travels. The device provides an output of absolute (Kg) and percentage (% of total mass) of fat mass (FM) and fat-free mass (FFM).

The SNAQ questionnaire is used to assess an older adults usual appetite. The SNAQ is a self-administered questionnaires adapted from the Appetite, Hunger and Sensory Perception questionnaire (AHSP), an appetite assessment tool validated among community-dwelling older adults. It consists of 4 multiple choice statements, where an individual reads the beginning of the statement and is presented with 5 options that best describe their situation. Each question derives a score between 1 - 5 with lower scores indicating poorer appetite. The questionnaire scores between 4 - 20 with scores </= 14 indicating poor appetite.

Rating of the breakfast and lunch test meals by visual analogue scales (VAS). The VAS is a validated tool for assessing subjective sensory experience. On each 100-mm line, a question is asked relating to sensory aspects of the meal (E.g., How pleasant was the meal?). The subject will mark along the 100mm line where they feel their experience, in terms of the question, rests. On ether end of the 100mm line are opposing terms (E.g., "not at all", "extremely").

Body weight will be measure using a calibrated scales, shoes and heavy clothing removes, and recorded in kilograms.

Height will be measured in centimetres using a stadiometer. Participants will be measured barefoot and asked to take a full inhalation prior to stepping out from the device. Measurements are taken at the peak of the inhalation.

Calf circumference is measures using a non-stretch tape measure at the widest part of the calf muscle and recorded in centimetres.

Questionnaire specific to the project. This questionnaire will serve to provide feedback about participants experience while enrolled on the project. The questionnaire will include a series of Likert style questions and open-ended questions. The purpose is the provide feedback to the study team on what participants liked or disliked about the experience. This will serve to inform future management of studies.

DXA will be performed on a sub-sample of participants enrolled on the APPETITE study. A DXA can involves a large scanning arm being passed over the body to measure compartments of the body structure. As the scanning arm is moved slowly over your body, a narrow beam of low-dose X-rays will be passed through the part of your body being examined. DXA is a quick and non-invasive scan that provides in-depth analysis of the main components of your body; fat, muscle and bone.

muscle signalling related to muscle plasticity, metabolism, denervation and muscle capillarization (sub-sample)

This refers to the analyses of muscle biopsies. Biopsies will be taken using MEDAX/BF14100-C0; Bio-Feather with coaxial 14 g 10 cm. The following parameters will then be measured in the sample using western blot with specific antibodies for total proteins or by their activated phosphorylated form: 1) markers of denervation (AChR ; agrin/MuSK/Lrp4, NCAM, Myog); 2) markers of protein turnover (atrogin1, MURF1, LC3, BNIP3, Akt-dependent mTOR and FoxO); 3) markers of mitochondrial dynamics (OPA1, DRP1) and; 4) markers of energy metabolism pathways (AMPK and PGC1alpha).

Trained immunity describes the long-term functional reprogramming of innate immune cells after exposure to a primary insult which leads to an augmented response upon stimulation with the same ligand after returning to a non-activated state. Will habitual ingestion of plant protein combined with PA results in increased ability of macrophages to undertake innate immune train in adults over the age of 65. Effects will be quantified by comparing the presence of TNF alpha in human monocytes at baseline and following a 12-week intervention.

Physical Activity Scale for the Elderly (PASE) is a brief (5 minutes) and easily scored survey designed specifically to assess physical activity in epidemiological studies of persons age 65 years and older

Adherence to the intervention requirements will be assessed using compliance diaries. Participants will record in a diary, provided by the study team, each time they consume the study product and/or complete a physical activity session. They will also collect empty sachets and return them to the study team at the end of the intervention. Compliance is considered adequate if 10 of a possible 14 supplements per week are consumed, and/or attendance of >80% structured physcial activity sessions.

This will take the form of a couple of questions during initial screening. The purpose of these questions is to assess whether the participant believes they can fulfil the intervention requirements if enrolled onto the study. The logic is to identify those who are unlikely to complete the study as a mechanism of reducing dropout rates. The questions will take the form of a Likert scale, and relate to the participants confidence, or lack thereof, to complete key requirements of the study.

12-week change in global cognition assessed by Mini Mental State Examination (MMSE). The MMSE is a commonly used tool to exam global cognition in both clinical and research setting. It is an 11-question measure that tests five areas of cognitive function: orientation, registration, attention and calculation, recall, and language. The maximum score for the MMSE is 30 points, where scores <24 would be indicative of cognitive dysfunction.

12-week change in depressive (Centre of Epidemiology Study - Depression) symptoms. The CES-D is a 20-item measure that rate how often over the past week an individual experienced symptoms associated with depression, such as restless sleep, poor appetite, and feeling lonely. Response options range from 0 to 3 for each item (0 = Rarely or None of the Time, 1 = Some or Little of the Time, 2 = Moderately or Much of the time, 3 = Most or Almost All the Time). Scores range from 0 to 60, with high scores indicating greater depressive symptoms. A score equal to or greater than 16 is indicative of risk of clinical depression.

Inclusion Criteria: Community-dwelling, Age 65+ years, BMI 19.5-30.4kg/m2, Inactive (<150 minutes of moderate to vigorous physical activity per week and no regular resistance training), Have proof of Covid-19 vaccination Exclusion Criteria: Major cognitive impairment (MMSE ≤24), Uncontrolled Clinical depression (CES-D >16), Medical condition or current medication known to impact appetite or energy intake, Other medical condition that may impact ability to participate in study or study outcomes, Heavy smoker (>10/day), Plans to relocate out of the study area within the next 6 months, Inability to come to study centre/PA program location, Currently participating in another intervention study, Inability to participate in physical activity, Unable to walk across a room, Allergic to or unwilling to consume any of the study test foods, Loss of taste or smell associated with COVID-19, Unwilling to be randomised to any intervention group.

Volkert D, et al. Innovative plAnt Protein fibre and Physical activity solutions to address poor appEtite and prevenT undernutrITion in oldEr adults - APPETITE. Nutrition Bulletin. 2021; 46: 486-496