A shopping intervention for cardiovascular disease prevention: a feasibility study
People recently found to have cholesterol levels above the healthy range.
An intervention to help people decrease their intake of saturated fat (SF) by using data on food purchases to provide personalised feedback on the saturated fat content of food purchases and suggest healthier alternatives.
This project is a proof-of-concept, or ‘feasibility’, study which aims to:
• develop a way to provide people with personalised feedback on the nutritional content of the foods they have recently bought, and offer advice on healthier alternatives
• develop a brief advice session, supported by written materials, that a health professional can use to people to help improve their diet and reduce their saturated fat intake; and
• test if these approaches, alone or in combination, help to decrease saturated fat intake among patients with raised cholesterol.
Why this is important
Cardiovascular disease, such as heart attacks and strokes, are the leading cause of death in the UK.
The types of food that people eat can strongly influence the risk of developing cardiovascular disease. Foods high in saturated fat, in particular, can raise this risk. Saturated fats mostly come from animal sources, such as butter or meat.
People can reduce the amount of saturated fat they eat by swapping some key foods in the diet for lower saturated fat alternatives. For example, swapping butter for olive oil-based spreads, or using turkey mince in place of beef mince.
Research has shown that reducing the intake of saturated fat can lead to big reductions in the amount of ‘bad’ LDL-cholesterol in the blood.
However, most of the previous research has either provided people with low-saturated fat foods to eat or intensive support and advice from nutrition specialists, or both. This would be impractical, expensive and time consuming for the NHS to provide on a scale which would be helpful for everyone found to have raised cholesterol levels.
A simpler, more automated, way of offering personalised advice on food choices could help to overcome these problems.
Most of the foods we purchase come from supermarkets and we will partner with a major retailer that will provide support for this project.
Most supermarkets already collect information on people's purchasing behaviours using loyalty cards. This allows purchases to be tracked, and the nutritional content of the food people buy to be analysed. In this way we may be able to deliver personalised nutrition advice and feedback.
This project aims to develop and test an intervention that helps people with high cholesterol levels to make healthier food purchasing choices.
First, we will develop a brief advice session with resources that health professionals can give to patients. This will aim to engage and motivate patients to consider dietary changes. It will also provide information on food choices to help reduce saturated fat intake. We will base this on the British Heart Foundation’s patient education booklet to help people reduce their saturated fat intakes.
The next step will be the development of a way to provide people with individualised feedback on the nutritional content of their food purchases each month. We will do this in partnership with a supermarket(s).
This feedback, in the form of monthly reports, will be based on people's recent food purchases, as recorded through loyalty cards. The report will include information on:
• total energy (calories);
• saturated fat intake;
• the major foods they bought which contained saturated fat; and
• personalised suggested lower saturated fat alternatives.
People will be able to use these reports to chart their progress in reducing saturated fat in their food shopping.
Once developed, we will run a small feasibility trial over 12 weeks to test if the new intervention can be delivered effectively to help people reduce saturated fat.
A feasibility trial is research done before a larger study in order to answer the question ‘Can this study be done?’. It gives us important information needed to design a larger study. For example, how willing clinicians or participants to take part, or the time needed to collect and analyse data, as well as indicating if the intervention itself works.
We will ask people to take part who have recently been found to have raised cholesterol levels and who are willing to change their diet.
We will randomly, but evenly, assign 90 people to one of three groups:
1) Usual care (awareness of high cholesterol).
2) Brief advice (to inform and motivate people to reduce their SFA intake).
3) Brief advice, food purchase data and personalised feedback on the saturated fat content of food, and suggested healthier alternatives.
In assessing this intervention, we will mainly be looking to see that the procedures can all be conducted efficiently. We will test whether the intervention helps participants to reduce the amount of saturated fat in their diet. We will also look at the saturated fat content of food bought over the 12 weeks. We will also look to see how this differs between the groups.
This will be measured using questionnaires, filled out by participants, on their eating behaviours and by using information on their food purchases.
We will also look for any effect the intervention has on a range of other measures, including:
• changes in total calories, fat, sugar and salt purchased; and
• changes in blood pressure, cholesterol levels and body weight.
If this small trial is successful and provides good evidence that we can deliver this intervention as planned, we will go on to perform a much larger trial of the intervention to test its effectiveness on a bigger sample of people. We will also see if this type of feedback can help people to lower their blood cholesterol level.
How this could benefit patients
Being able to offer straightforward and personalised advice to help people reduce their intake of saturated fat has the potential to reduce the risk of serious cardiovascular diseases for a large number of people.
We hope it will encourage the food industry to do more to help people change their diet and improve their health.
In addition to this being a potentially cost-effective approach to reducing cardiovascular disease, it could also increase people’s quality of life, and free up NHS resources for other people and conditions.
If this is successful we will test how this kind of information could help people change other aspects of their diet, such as eating less salt or sugar to reduce the risk of high blood pressure or diabetes.