Supporting people to lose weight by self-weighing
Many people who are successful at losing weight and keeping it off say that weighing themselves every day is key to their success. However, asking people to adopt this habit is not enough to help them lose weight. We need to understand what’s missing. What are the thoughts and feelings that people who do this successfully have when they stand on the scales?
- To use research in psychology to understand the way that weighing yourself daily creates thoughts and feelings that help or hinder weight loss
- To refine this understanding, using a small number of volunteers who are trying to lose weight, to identify the patterns of thoughts and feelings that help people commit to and sustain their action on weight
- To develop a mobile phone app to that people can use to coach them in helpful responses to their daily weight record and to test its impact on weight loss
WHY THIS IS IMPORTANT
In England, the number of overweight or obese people has been steadily rising. Between 1993 and 2014 obesity among adults rose from 15% to 26%, while a further 36% are overweight.
Generally, we use the body mass index (BMI), which is calculated from a person’s height and weight, to classify people as overweight and obese. A BMI of 25-29.9 suggests a person is overweight, while a BMI of 30 or more classifies a person as obese.
Each kilogram of extra fat increases people’s risk of a host of health problems. This includes diseases such as high blood pressure, stroke, colon cancer, diabetes, and arthritis. By the same token, losing only a kilogram of extra fat reduces blood pressure and reduces the risk of diabetes.
Most people have a bit of fat they would like to lose, being able to offer simple, proven and effective tools and strategies to help people lose weight is ever more important.
Among these tools is self-weighing.
There is good evidence that those who are most successful at losing or maintaining weight tend to weigh themselves regularly.
Other studies have shown that adding self-weighing to other types of weight loss strategies also increases weight loss.
Why this may be, we aren't 100% certain. Current thinking is that self-weighing helps to encourage people to reflect on, and plan to correct, the actions which affect their weight.
So the question we asked is: would self-weighing on its own help people reflect and plan? We carried out a trial that simply asked people who wanted to lose weight to weigh themselves, without any other support. We found no evidence that self-weighing made people more successful at losing their weight than people who didn’t weigh themselves.
We believe that what was lacking for these people was the support and guidance needed to develop the ability to reflect on their actions, plan to achieve weight loss and, perhaps, manage competing emotions.
Our research aims firstly to identify the emotional strategies and reflection and planning needed to help people lose weight. Then we will try to create a programme, or ‘app’, for mobile phones that coaches people to use these strategies and test its effectiveness.
This project will be split into three stages.
The first stage will review the existing scientific literature which examines the psychological and behavioural processes that can make self-weighing an effective tool.
We will use the findings from this to make a model of how the process works. The model will describe what behaviours and thoughts turn self-weighing from a simple monitoring activity into a useful tool to help you learn about diet and activity and its effects on weight.
We will test this model using volunteers who are overweight and trying to lose weight.
As they weigh themselves each day we will ask them to ‘think aloud’ about their emotions and thoughts, and to record this on their phones. Some will be successful at losing weight, others will not.
We will use the recordings to examine the emotional and thought patterns associated with successful weight loss, and what goes wrong in those that don’t succeed. In this way, we will be able to coach people better in what they do.
Once we have a model we are confident in, we will construct a phone app that uses the model to coach people through the steps which best aid weight loss when self-weighing, and also logs their weight over time.
We will refine the app using feedback from initial users, to ensure that it works as intended and is seen as helpful by the people using it.
We will perform a small trial of the app to understand whether a larger trial would be practical and possible (a feasibility study), and measure its impact on weight loss in the short-term.
80 people will be assigned by chance to one of two groups, half in one, half in the other. One group will receive a self-help booklet on how to lose weight and the other will receive the booklet and use the self-weighing coaching app.
We will look to see if people using the coaching functionality lose more weight after two months than those who did not.
If so, this would suggest the app improves weight loss by self-weighing, and that a larger study to test this with more people is worthwhile.
HOW THIS COULD BENEFIT PATIENTS
Identifying effective ways for overweight and obese people to lose weight could significantly reduce people's risk for a wide range of diseases and life-limiting health problems, boosting their quality of life. The sheer scale of the problem means we need low-cost solutions. The use of a phone-based would be a very cost-effective way of achieving this.