The study consists of data capturing to evaluate the differential pattern of molecular markers of immunosenescence in different population groups, and applying a hypocaloric diet in the obesity subgroup together with recommendations for improving lifestyle habits. The data capture of this group during the intervention will be carried out with different sensors and questionnaires for a month. To do this, they will have to follow the explanations of the researchers.~The data capture during the nutritional intervention (only for the overweight and obese population group) will be done as follows:~Group 1 (Traditional → Digital): will start with traditional data-collection methods, i.e. filling in nutritional and lifestyle questionnaires (Visit 1 to Visit 2). After two weeks, they will start capturing data digitally through the application of sensors (Visit 2 to Visit 3).~Group 2 (Digital → Traditional): will start with digital data-collection methods, using sensors and taking pictures of what they eat with a smartphone (Visit 1 to Visit 2). After two weeks, they will start capturing data traditionally, by filling in nutritional and lifestyle questionnaires (Visit 2 to Visit 3).~The nutritional intervention participant group will follow the tailored nutritional weight loss diet and lifestyle guidelines, which will be provided to them at the start of the study by the researchers. In addition, they should follow instructions for proper continuous data collection using sensors. This will avoid biases in the data collection process.
Descriptive comparative study of immunosenescence markers and their association with nutritional, metabolic, metabolomic and genetic characteristics in young (control), senior (age-associated immunosenescence), and populations susceptible to premature immunosenescence such as obese patients, cancer patients and patients who developed severe forms of COVID19 or persistent COVID19.~In one of these populations of premature immunosenescence, the population group with overweight or obesity, a prospective and cross-sectional nutritional intervention study is proposed, with data capture and monitoring using digital tools, to evaluate the evolution of immunosenescence markers and assess more objectively and effectively the nutritional status and help in making personalised decisions thanks to the application of these tools. This nutritional intervention will be focused on controlled and safe weight loss that will allow the capture of a large number of variables on lifestyle and dietary habits, nutritional assessment, biochemical, metabolic, genetic, metagenomic, lipidomic and metabolomic markers measured statically and also continuously.