Rationale: Improving dietary behaviours in view of optimising risk factors of metabolic syndrome requires behaviour change strategies. Tailored dietary advice, i.e. recommendations offered as a guide to action, can support behaviour change. In the current study we aim to learn how to better help consumers in their daily life to make lifestyle choices that better match their personal health target than their usual choices by providing personalised advice and feedback. In this study we target consumers at risk of metabolic syndrome (MetS) that are highly motivated to change their dietary behaviour in view of improving health.

Objective: The primary objective is to investigate the potential of personalised dietary advice and feedback for initiating and maintaining dietary changes by consumers at risk of MetS. In addition we want to evaluate understanding, applicability and personal benefit of personalised dietary advice and feedback by the target population to be able to further optimize the personalisation in future studies. The secondary objective is to explore potential effects of personalised dietary advice and feedback on subjective health and metabolic health parameters.

Study design: The study follows a one group pre-test post-test design with a duration of 16 weeks after the first advice is provided to the participants.

Study population: In total 40 adult men and women at risk of metabolic syndrome will be recruited from the consumer databases of Wageningen Food & Biobased Research. Consumers are eligible for study participation when they are highly motivated to change dietary behaviour, willing to use technology, willing to share food purchase data as registered on a customer card of the supermarket, and in possession of a smart-phone.

Intervention: The intervention consists of personalised dietary advice and feedback on actual behaviour and health status that will be provided to study participants at set time points throughout the study period. The content of the advice will be generated partly automated based on dietary intake and parameters of metabolic health using knowledge rules that are developed for this study. During a consultation with the dietician, the advice is then translated in a dietary behaviour change strategy by taking into account individual preferences through motivational interviewing.

Main study parameters/endpoints: Primary outcomes of the study are the adequacy of intake of fruits, vegetables, whole grain products, dairy, fish, fats & oils, red meat, processed meat, and sweetened beverages & fruit juices as estimated by the online tool Eetscore. Furthermore consumer experiences and individual benefits of the provided personalised dietary advice are monitored on a weekly basis throughout the intervention period.

Inclusion Criteria:

• Having given written informed consent
• Aged 40 years or over
• At risk of metabolic syndrome
• Motivated to change behaviour
• Willing to use technology (digital platforms, activity tracker, digital questionnaires, apps)
• Customer of supermarket Albert Heijn (at least 1x per week) and in possession of customer card
• Willing to share food purchase data as registered with the Bonuskaart with the investigators
• In possession of I-phone or mobile phone with android system

Exclusion Criteria:

• Use of medication known for its effects on blood glucose, cholesterol or insulin
• Suffering from diabetes
• Familial hypercholesterolemia
• Following a specific diet
• Having an alcohol consumption > 28 units/week for males and > 21 units (drinks)/week for females
• Does not accept that the general practitioner will be informed about participation of the study
• Having holidays planned for a period of more than two weeks during the intervention period