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)

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.

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.