This study aims to assess the effect of protein on appetite, food intake and gastric emptying in older adults (≥ 65 years) that are more and less active.

To investigate the differences in food intake in older adults that are more or less active and assess any differential responses to protein intake.

To compare the effect of meals with high or low protein level but equal in energy and volume on appetite and gastric emptying in older adults that are more or less active (≥ 65 years).

Inclusion Criteria:

• healthy
• aged ≥ 65 years

Exclusion Criteria:

• having diabetes or disability or any disease that are likely to influence physical activity or appetite.
• having an allergy to any of the test foods;
• disliking or cannot eat any of the test foods;
• being obese (BMI > 30 kg/m2);
• taking medications known to influence appetite, food intake or body weight in the past three months;
• being on a weight loss diet;
• smoking more than 10 cigarettes a day;
• not meeting the cut-off point criteria based on the accelerometer data (108.25 ≤ min/per day of moderate and vigorous activity for women or 162 ≥ min/per day moderate and vigorous activity for women and 100.1 ≤ min/per day of moderate and vigorous activity for men or 133.25 ≥ min/per day moderate and vigorous activity for men).

No personal identification data will be shared. The study is not under an obligation to share data, however, it is possible that some of the individual (unliked / non-identifiable) data will be useful in a meta-analysis and, hence sharing individual participant data (IPD) will be considered.

Single (Participants)