Precision Nutrition Strategies for Improving the Quality of Life of Pre-senior and Senior Populations

This study is designed as a 12-week, randomized parallel intervention trial, with two arms: 1) Control group, who follows a control diet based on the current dietary guidelines of the Spanish Society of Community Nutrition (SENC) using the Healthy Eating Plate method (Harvard), and 2) Nutriprecision Group, which were instructed to follow the Nutriprecision diet based on the inclusion of digital tools and functional foods, whose postprandial effects were previously evaluated by randomized, cross-over, double-blind studies in senior subjects in the Centre for Nutrition Research (UNAV) and IMDEA-ALIMENTACIÓN. The incremental area under the curve (iAUC) for glucose and insulin was calculated for all designed foods and was compared with their reference products. Additionally, lipid profile and satiety were measured at fasting and at 15, 30, 45, 60, 90, and 120 min after starting the food intake. In all these studies, the reference and test foods were administered once in random order, with a wash-out period between 7 days and 14 days among assays. This multi-centric study was carried out in the Nutrition Intervention Unit of the Centre for Nutrition Research in the University of Navarra and the Nutritional and Clinical Trials Unit in IMDEA-ALIMENTACIÓN by qualified professionals (nurse, doctor-dietician, dieticians, pharmacists). A total of five visits had been established along with the 12-weeks trial: 1) study information and screening; 2) day 0: start of the intervention; 3) day 28: group session (control group)/follow-up visit (Nutriprecision group); 4) day 56: group session (control group)/follow-up visit (Nutriprecision group) and 5) day 84: end of the intervention. At the start and finish days of the study, participants visited the Nutrition Intervention Unit or the Clinical Trials Unit in a fasting state. Participants were instructed to collect the first-morning urine sample. Additionally, volunteers from the University of Navarra self-collected fecal samples at baseline using OMNIgene.GUT kits from DNA Genotek. Volunteers were also informed of a digital-based procedure for cognitive assessment and other digital tools available depending on the assigned intervention (experimental VS control). Blood samples were drawn by venipuncture after a 12 h overnight fast in a clinical setting. After 10 minutes of rest and having answered the Mini Nutritional Assessment (MNA) and the Mini-Mental State Examination (MMSE) questionnaires, blood pressure was measured. Later, anthropometric measurements and body composition analysis were performed. Global cognitive performance was also assessed by the Guttmann NeuroPersonalTrainer platform. The duration of these visits was approximately 1 hour. On the 28th and 56th study days, participants assigned to the control group attended online group sessions and received intensive education and advice to increase the adherence to the dietary strategy. Sessions consisted of informative talks about the prescribed dietary pattern, food label use, seasonal shopping lists, meal plans and recipes, physical activity and exercise recommendations, sleep habits, etc. Contrary, participants allocated to the Nutriprecision group attended in person visits with the dieticians, to evaluate the adherence to the assigned nutritional treatment. Additionally, anthropometric, body composition, and blood pressure measurements were assessed. Participants were also asked to fill different questionnaires about health status (SF-36 Health Survey), gastrointestinal symptoms (gastrointestinal symptoms rating scale, GSRT), dietary assessment (7-day recall), Mediterranean diet adherence (14-Item Mediterranean Diet Assessment Tool), physical activity (International Physical Activity Questionnaire, IPAQ) and drug therapy modifications. Moreover, the Nutriprecision group were asked to collect a sensory perception questionnaire and a food consumption record of the precision foods administered.