The alteration maintained over time of some metabolic processes, such as oxidative stress, low-grade inflammation, carbohydrate and lipid metabolism, and of the intestinal microbiota activity, can induce some chronic diseases with high prevalence in society, such as obesity, cardiovascular disease or diabetes. These metabolic alterations can be modulated through nutrition and eating habits. Thus nutritional interventions are currently considered as a main tool for disease prevention.

The need to adapt nutritional interventions to the particular needs of each person in order to improve the health status of all individuals is becoming more and more evident, through precision nutrition. On the other hand, for nutritional interventions to be carried out over long periods of time and to achieve sustainable long-term changes in lifestyle, new forms of behavioral counseling are necessary to facilitate the follow-up of nutritional interventions.

PREVENTOMICS is a European project that arose to develop a personalized nutrition system, the PREVENTOMICS system. This system is based on the classification of the users of the system according to the state of their own metabolic processes, their genotype, their dietary habits and preferences, levels of physical activity, purchase preference and possible allergies, in order to provide a personalized nutrition adapted to the needs of each user.

The PREVENTOMICS system is presented through a digital environment via computer, with a list of products provided by the ALDI supermarket to prepare the shopping list, without having to buy the products from the ALDI supermarket.

Nowadays, diet is recognized as one of the most important factors in the development of non-communicable diseases. Therefore, nutrition and dietary habits stand out as an invaluable tool for preventing diseases. Among these dietary habits, Mediterranean diet is now recognized as one of the best models of food patterns providing protection against chronic diseases and with beneficial effects on quality of life.

During the last years, expectation on precision nutrition beyond personalized diet has been increasing due to the possibility of adapting diet to the actual needs of the person, optimizing the function of the organism. Currently, diet precision in the context of general population is mainly addressed to heterogeneous groups of population, depending on variables such as age, gender or physical state among others. Beyond this approach, a more accurate personalization strategy is based on adapting some components of the diet to the genetic profile of the subject while considering a limited number of phenotypical traits.

Some authors have proposed that a wide array of chronic non-communicable diseases of high prevalence in our society have a multifactorial origin, being the result of a sustained dysregulation of some physiological processes, such as metabolic stress, oxidative stress, chronic systemic low-grade inflammation or psychological stress among others. Since most of these processes can be modulated by diet, optimizing them by means of nutritional interventions could represent an invaluable approach for preventing diseases. Nevertheless, a complete characterization of these physiological processes is needed in order to know their real state in individuals and be able to deliver an adequate intervention for their restoration when required. Currently, -omics technologies provide the necessary tools for accurate assessing the state of these physiological processes.

In this context, PREVENTOMICS project financed by the European Research and Innovation programme H2020 (Call H2020-SFS-2018-2020; DT-SFS-14-2018; Project title : Empowering consumers to PREVENT diet-related diseases through OMICS sciences) and with a consortium of different companies and public entities, including EURECAT, aims to assess the most relevant metabolic processes which dysregulation leads to the onset of disease and to integrate individual's metabolic signature with genetic, biological, nutritional and psychological aspects through Information and communication Technologies (ICTs) to deliver preventive personalized nutrition tools in order to correct early deviations.

The main concept behind the PREVENTOMICS project is to provide personalized recommendations based on a multi-level classification after clustering the different users according to their dietary habits and preferences, their levels of physical activity, shopping preferences, possible allergies and phenotypic (i.e. metabolomics and proteomics-based multivariate approach) and genotype characterization.

To achieve the main objective, the PREVENTOMICs project consortium has developed a personalized nutrition strategy based on a recommender system in order to provide personalized nutrition tailored to the actual status of the subject.

To do that, the physiological processes considered in PREVENTOMICS have been selected according to their relevance with health and disease, to nutritional status and, therefore, their ability for being modulated by nutritional interventions.

These processes are:1) oxidative stress; 2) systemic inflammation; 3) carbohydrate metabolism; 4) lipid metabolism; 5) microbiota status through the measurement of microbiota generated metabolites.

In order to define the status of these physiological process, classically accepted biomarkers already used in clinical assessment and intervention studies will be determined, including blood triglycerides, cholesterol, C-reactive protein, glucose or urine isoprostanes among others. Moreover, the recommender system developed in PREVENTOMICS combines these measurements with other biomarkers that have been sufficiently well characterized as surrogates for studying specific metabolic processes.

With the above information, the PREVENTOMICS recommender system also integrates a panel of single nucleotide polymorphisms (SNPs).

Besides, behavioural research shows clearly that the provision of knowledge and advice as a means to help people make changes in their lifestyles does not necessarily result in the desired behavioural change. Therefore, in order to achieve sustainable long-term lifestyle changes, people need to be prompted to behave in new ways that do not rely on their willpower or conscious thinking.

Therefore, the recommender system will anonymously collect data on analyzed biomarkers, habits, mental wellbeing levels, cognitive health, social inclusion and behaviours and will translate this using behavioural change algorithms along with digital delivery into a series of personalised, goal-orientated, friendly, and achievable actions proposed to the user.

Thus, to achieve PREVENTOMICS project objectives, a consortium of 19 partners was created including:

1. 4 small medium-sized enterprises (Alimentomica, Carinsa, Do Something Different and Practico);
2. 9 research performing institutions (Eurecat, University of Parma, University of Southampton-Southampton General Hospital, Institute of Communication and Computer Systems, Maastrich University, Wageningen University, Leitat, Jagiellonian University Medical College);
3. 3 companies with exploitation interests (SimpleFeast, Meteda and Aldi)
4. A consumer association OCU;
5. A standardization body, UNE;
6. Osteoarthritis Foundation International - OAFI.

The main outcome of the PREVENTOMICS project has been a novel recommender system that can be used in a wide array of applications or business models. Within the PREVENTOMIC project, three different applications of the system are evaluated:

1. Personalization of weekly menus delivered at home (catering).
2. Adaptation of professional tools for nutritionists and dieticians (advanced tools for health professionals).
3. Personalized shopping experience in supermarket (retailers).

In PREVENTOMICS project, the UTNS of Eurecat in Reus is focused in personalized shopping experience together with ALDI supermarkets and will conduct the study with clinically healthy adults and using a dedicated ALDI microwebsite to assess application number 3.

The ALDI microsite uses the personalized recommendations generated by the recommender system to provide each user the most appropriate diet-based nutritional and behavioural changes recommendations according to the individual's needs, lifestyle and preferences and personalizing the shopping experience in ALDI's online supermarket.

Importantly, despite the proposed use of such workflow might be demonstration of personalized online shopping, the pilot carried out in Reus does not support trading. Therefore, users will use the ALDI microsite to generate a shopping list navigating through a personalized ALDI catalog, but they are free to shop at any retailer other than ALDI.

The improvement in dietary habits will be based on the Mediterranean diet adherence as a reference, as this diet is recognized as one gold standard.

The hypothesis of the present study is that empowering consumers with tools that adapt nutrition recommendations to individual's metabolic state, lifestyle and food preferences through the utilization of the recommender system developed in PREVENTOMICS, with or without the application of behavioral change programs, will promote favorable and sustained changes in personal dietary behavior and food choices at the supermarket, promoting Mediterranean diet and beneficial effects on the health status of individuals.

The main objective of the present study is to assess the soundness of the personalized nutrition advice generated by the recommender system and its combination with a behavioral change intervention, to improve dietary habits of individuals compared to standard and generic nutritional advice, measured through adherence to the Mediterranean diet and delivered through a retailer website (ALDI microsite).

The secondary objectives are to evaluate the effects of using the personalized nutrition advice provided by PREVENTOMICS through a retailer website on:

• Anthropometric measurements.
• Blood pressure.
• Metabolic profile.

After the selection visit (V0), on the first visit (V1), the 180 participants will provide urine, stool and saliva samples and will fill different questionnaires (quality of life, behavior, frequency of food consumption and physical activity) with the help of nutritionists. Additionally, participants will be randomly divided into three groups of 60 participants as they receive: 1) personalized nutritional advice; 2) personalized nutritional and behavior change advice; or 3) general non-personalized nutritional advice. With the samples provided in the first visit, a complete analysis of the metabolic and genetic status of each participant will be carried out, which will be used for, approximately after a month, the participant begins to use the digital environment to generate their shopping list. Users will follow the nutritional advice that corresponds to them according to the assigned group and through the PREVENTOMICS system for 4 months. After 4 months, participants will make the last study visit (V2) where they will repeat the same process described for the first visit to assess the effects of the intervention.

During the study, 3 visits will be carried out:

• One selection visit (V0; week 1) to check inclusion / exclusion criteria in the study and provide the necessary material for collecting stool and urine samples, as well as a three-day dietary record.
• A visit start of the study (V1; week 2) in which the participant will bring the biological samples, will fill the questionnaires and three-day dietary record, will have blood drawn and obtain a saliva sample, and will be included in one of the three study groups.
• A visit of completion of the study (V2; week 25), in which the participant will bring the biological samples, will have blood drawn and will fill out the questionnaires and three-day dietary record.

Monthly, except for the last month of the study, the participant will be followed up by phone call. In the last one, there will be a face-to-face follow-up visit to give the volunteers the materials for collecting biological samples and the three-day dietary record for the V2 visit. In addition, the participants will have personalized support by phone and via email for any questions or problems that may arise during the study.

Inclusion Criteria:

• Men and women.
• Signed informed consent.
• To have internet access.

Exclusion Criteria:

• Diabetes (or glucose ≥ 126 mg/dL or pharmacological treatment).
• Hypertension (systolic blood pressure ≥160 mmHg and/or diastolic blood pressure ≥100 mmHg or pharmacological treatment).
• Dyslipidaemia (cLDL ≥4.9 mmol/L and/or triglycerides ≥4.5 mmol/L (≥400 mg/dL) and/or cHDL <40 mg/dL (1.03 mmol/L) in men and <50 mg/dL (1.29 mmol/L) in women) or with pharmacological treatment.
• Use of prescribed medicine to control acute or chronic inflammation.
• Anaemia (haemoglobin ≤13 g/dL in men and ≤12 g/dL in women)
• BMI (in kg/m2) <18.5 or >35.
• Being pregnant or planning to become pregnant within the study period.
• Be in breastfeeding period.
• Current smokers.
• Participate in or have participate in a clinical trial or nutritional intervention study in the last 30 days prior to inclusion in the study.
• Present some chronic gastrointestinal disease.
• Present some chronic disease with clinical manifestation, like coronary heart diseases, cardiovascular disease, coeliac disease, Crohn's disease and chronic kidney disease (or serum creatinine ≥1.7 mg/dL for men and ≥1.5 mg/dL for women).
• Following a prescribed diet for any reason, including weight loss, in the last 3 months.
• Following a pharmacological treatment for weight loss or intake of food supplements or medications that could affect body weight.
• Having allergies or food intolerances.
• No or limited access to the Internet.
• Consumption of more than 14 drinks of alcoholic beverages per week.
• Mediterranean Diet Adherence Score (MEDAS) > 8 of 14 points, which is a food pattern already highly concordant with the Mediterranean Diet.
• Being unable to follow the study guidelines.

The data sharing plans for the current study are unknown and will be made available at a later date