Background: The PROMISS randomised controlled trial showed that personalised dietary advice increased protein intake and improved 400-m walk time and leg strength among community-dwelling older adults with a low habitual protein intake. This secondary analysis describes and further evaluates the methods and feasibility of the model used to carry out dietary intervention in the PROMISS randomised controlled trial.

Methods: In total, 185 participants (≥65 years, 54% women) with a habitual low protein intake (<1.0 g/kg adjusted body weight/day) in Finland and the Netherlands received personalised dietary advice and complimentary protein-enriched food products for 6 months with two main

Objectives: (1) to increase protein intake to ≥1.2 g/kg adjusted body weight/day (energy-neutral) and (2) to include each day a 'high-protein meal' containing ≥ 30-35 g of protein. The feasibility of the model was evaluated by the adoption of the advice, feedback from the participants, and practical experiences by the nutritionists.

Results: In all, 174 participants (93.5%) completed the intervention. At the 6-month follow-up, 41.8% reached both main objectives of the advice. The participants' general rating for the dietary advice was 8.6 (SD 1.0) (on a scale of 1-10; 10 indicating very good). Sticking to the advice was (very) easy for 79.2% of the participants. The nutritionists perceived the model feasible for the participants except for those with low food intake.

Conclusions: The methods used in this model are mainly feasible, well-received and effective in increasing protein intake among community-dwelling older adults with low habitual protein intake.