Personalized dietary advice

Rationale: Households with a low Socio-economic Status (SES) are less healthy and have less healthy diets as compared to those with a medium or high SES. This group is often difficult to motivate to change their diet even while it would improve their health. Interventions that could help low SES households to learn how to change their diet in such a way that it is easy and motivating for them to do so are therefore needed. We hypothesize that providing personalized feedback on one’s health and diet will help low SES consumers to improve their diet, and even more so if personalized dietary advice is added to the feedback.

Objective: The aim of this pilot-study is to evaluate the feasibility of the intervention and to gain insights in experiences and motivations of low SES households in order to improve the proposed program. A second aim is to explore the effectiveness of demonstrate whether personalized feedback and dietary advice can in empowering low SES households to improve their diets based on personalized small adaptations to their diets. A second aim is to gain insights in experiences and motivations of low SES households in order to improve the proposed program.

Study population: 110 customers of Jumbo Geinplein and Jumbo Almere Buiten will be recruited within the supermarket. Low socio-economic status will be operationalized as customers with a low level of education (maximum MBO 2).

Intervention (if applicable): The study design will be a randomized and stratified intervention study with a duration of four weeks with three treatment groups. All participants will be subjected to measurements at the start and end of the study regarding health status, food intake, intentions to consume a healthy diet and a range of socio-psychological variables. The control treatment will only be measured. The feedback treatment receives personal feedback on how well they score on the health measures and on their diet. The advice treatment receives feedback in the same way as the feedback treatment and additionally receives personalized dietary advice on a product category of own choice.

Main study parameters/endpoints: This study will look at both immediate and long term effects (4 weeks) of personalized feedback and advice both between (across conditions) and within subjects (over time). The main study parameters are dietary intake, food purchases, dietary intentions, and perceptions of self-efficacy, health, healthiness of the diet and knowledge. Qualitative data will be collected to investigate consumers experience and motivations related to the offered personalized nutrition intervention.

We hypothesize that providing personalized feedback on one’s health and diet will help low socio-economic status consumers to improve their dietary pattern, and even more so if personalized dietary advice is added to the feedback.



The pilot study has two objectives:

- A primary objective of the proposed study is to evaluate the feasibility of the intervention, both in terms of consumer feasibility as well as technical feasibility. User satisfaction with the intervention will be researched.

- The secondary objective of the proposed pilot-study is to explore the effectiveness of personalized feedback and advice in enhancing the diet of low SES households, by empowering them to make healthy adaptations to their diets based on personalized small steps. The study will include a first exploration of the effectiveness on the participants’:

• diet (intentions, actual diet and household purchases),

• health (BMI, waist circumference and blood pressure) and

• psychological characteristics (perceptions of one’s self-efficacy, health, healthiness of the diet and knowledge on healthy food).

At baseline (T=0) and at the end of the study (T=4), several health indicators, diet, purchases and several socio-psychological variables will be measured.



• Dietary intake: The EETSCORE will be used



• Intentions to consume a healthy diet: 3-items, 7-point scale.



• Customer experiences and motivations: Qualitative data will be collected to investigate consumers experience and motivations related to the offered personalized nutrition intervention.



• Health parameters (T=0 and T=4):

o Body Mass Index (BMI) [kg/m2]

o Waist circumference [cm]

o Blood pressure



• Socio-psychological parameters (T=0 and T=4):

o Perceived self-efficacy: Strecher et al., 1986

o Perceived knowledge: 2 items, 7-point scale

o Perceived health: 1 item, 7-point scale

o Perceived healthiness of the diet: 1 item, 7-point scale



• Food purchases (t=0 and t=4)

Healthiness of (household) purchases will be evaluated by analysing the receipt of the participant. Healthy/unhealthy ratio will be calculated as well as the percentage of purchases in each category.

The intervention consists of 3 treatments:

- a control treatment --> This treatment is only measured, but does not receive any placebo or intervention, so therefore I have selected the option 'not applicable' in the menu above.

- a feedback treatment

- A personalized advice treatment



The study design will be a randomized and stratified intervention study with a duration of four weeks with three treatment groups. All participants will be subjected to measurements at the start and end of the study regarding health status, food intake (Eetscore), intentions to consume a healthy diet and a range of socio-psychological variables. The control treatment will only be measured. The feedback treatment receives personal feedback on how well they score on the health measures and on their diet. The advice treatment receives feedback in the same way as the feedback treatment and additionally receives personalized dietary advice on a product category of own choice.