This service evaluation reports the efficacy of a 12-week weight management programme offered online, incorporating some of the behavioural change support that would normally be offered within in-person groups. The service evaluation is bespoke to those adults who accessed the online support via Public Health England’s Better Health national campaign where they were able to obtain a discounted rate for their membership.
Over 25,000 UK adults accessed Slimming World’s online support during the three-month study period. Over 60% of the study population were people living with obesity and more than 20% achieved a weight loss of 5% or greater. The mean weight loss of 3% over this initial 12-week membership meets the recommendations for weight management programmes advised by the NICE guidelines (NICE, 2014)1. The mean absolute weight loss reported is 1kg greater than the weight loss reported in the OWLET trial2 where participants also accessed online weight management support although the study population in our evaluation had selected to access the online support rather than being randomised to the support and referred via primary care. A meta-analysis of 61 studies found similar results with greater weight loss (kg) post intervention in digital weight loss interventions compared to minimal or standard care (MD − 2.70 [− 3.33,−2.08], p < 0.001)3.
Whilst men only represented just over 5% of the study population, their weight losses were greater than females. This data is in line with other studies where weight loss in males has been reported to be consistently higher than in females attending mixed-sex programmes4, 5. Men are also under-represented in weight loss research with a systematic review of 244 randomised controlled trials of weight management programmes reporting that only 27% of the > 95,000 participants were men6. The problem remains how to encourage more men to engage with weight management programmes whether online or in-person groups. Qualitative data suggests that men do not think that it is a male thing to be worrying about their weight and there is a certain amount of stigma for men unless they have a medical diagnosis or health threat and are referred to lose weight by a medical practitioner7.
Also consistent with recent reviews3, 8, 9, those people who were perceived as engaging more with the online support, were more successful in their level of reported weight loss. Level of engagement may be associated with greater commitment10 and self-monitoring weight via uploading personal weight on a weekly basis could be motivating11. Baseline BMI did influence absolute but not percentage weight loss for both the total study population and the high engagers. Whilst important that those people joining with higher baseline BMIs were able to lose more absolute weight, a 3% weight loss may not be clinically significant where baseline BMI is over 35kg/m2 and either a greater level or length of engagement needs to be encouraged to achieve a weight loss nearer 5%.
It can be more difficult for people from lower socioeconomic backgrounds to achieve healthier lifestyles because of the direct and tangible costs of following a healthier diet12 and increasing activity through the use of structured exercise programmes13. However female adults from the lowest socioeconomic groups present with higher levels of obesity14 and thus may benefit more from weight management support. In terms of reducing health inequalities, it is very important that publicly funded programmes provide equity of access and if possible try and target people from more vulnerable populations including people from lower socioeconomic groups. Thus it is pleasing that almost a third of those people accessing the support were from the two most deprived groups when the IMD data was split into quintiles of deprivation. Even more important was the finding that the people who engaged from the two most deprived groups were equally likely to achieve the same levels of weight loss. This would suggest that the guidance provided through the online support was appropriately ‘pitched’ to all those engaging irrespective of their socioeconomic background.
Previous studies that have investigated the effectiveness of behavioural weight loss programmes delivered in everyday contexts suggest that commercial interventions delivered in the community are effective for achieving weight loss15 and represent good value for money16. For some individuals online weight management support may lead to greater weight loss outcomes compared to in-person group support particularly in the short-term17. It may also be more cost effective to deliver at scale. The Slimming World online support has been designed to provide similar personal behaviour change guidance and support tools as offered in the in-person groups, including access to an online member community and live events to provide a level of peer support but some people may struggle to engage as fully as they would in person. The current data was collected during the COVID pandemic which was known to generally affected people’s eating habits and mental well-being, with a number of studies reporting that people found it more difficult to manage their weight during this time18, 19, 20. The jury is out as to whether greater weight loss is achieved if people have to pay for weight management services that they can afford or whether there are benefits of people being referred into a subsidised programme at no cost to themselves21. People accessing the Better Health programme were effectively self-funding a subsidised programme offered via PHE. Also, they had selected the Slimming World programme rather than other choices so theoretically should have been prepared to make changes.
One of the limitations of this current evaluation of the online support offered via Slimming World is that the study population was limited to those who had had time to complete the 12-week programme at the time data was downloaded. Hence the data reported is not for all adults who have accessed the Slimming World online support via Better Health. The data was downloaded at the end of the 12-week intervention and longer term follow up data would provide additional information as to whether the weight losses achieved could be further enhanced or, at the minimum, be maintained. The findings from the in-person group population are that weight losses achieved can be maintained at one year follow-up22 and also that around half of people who were referred continue to attend after the initial 12-week referral23.
Baseline data collection was limited to age, gender, BMI and IMD index. We did not collect data on other health parameters, use of medication, dietary and physical activity changes made or collected any qualitative data. Other studies undertaken by the Slimming World research team have found that people accessing the support make behavioural changes including positive dietary changes and increase their physical activity levels24.
Pragmatic and scalable national solutions are required for community weight management services that can be easily accessed by people living with obesity from different socioeconomic groups. This service evaluation shows that an online programme, offered as part of a national campaign led by PHE, can provide effective support to a large number of people with different starting BMIs and from different socio-economic backgrounds. As always, an increased level of engagement can lead to better weight loss outcomes.