Long term lifestyle changes – tips from the PREVIEW Study Australia
Worldwide, type 2 diabetes (T2D) is one of the fastest growing chronic conditions, fuelled by the increasing rates of overweight and obesity.1 The diagnosis of pre-diabetes provides a window of opportunity to slow or reverse the progression to T2D at every life stage – whether young, starting a family or middle-to-old-age.
The PREVIEW study is a landmark study in diabetes prevention and weight loss management.3 This multi-cultural international study involved centres in Denmark, Finland, United Kingdom, the Netherlands, Spain, Bulgaria, New Zealand and Australia, with participants diagnosed with pre-diabetes ranging from 25 to 70 years of age. It is a randomised controlled trial consisting of a weight loss phase and a weight maintenance phase run over three years. The initial weight loss phase consisted of an 8-week total diet replacement and participants were required to lose at least 8% of their original body weight to continue in the study. They were then randomised to one of the four treatment groups in a 2 x 2 factorial design. The two diets were: higher protein (25% energy) with lower glycemic index (GI) carbohydrate (carbohydrate 45% of energy; GI <50) or a moderate protein (15% energy) with a typical GI diet (carbohydrate 55% energy; GI>56). The two exercise regimes were: moderate (60-75% heart rate maximum for 150 mins) or high intensity (76-90% heart rate maximum for 75mins) exercise. The participants were involved in 17 group sessions with a fading frequency of contact over the three years of the study. The group sessions were underpinned by a specifically designed theory-orientated group behaviour change program called PREMIT (PREview behaviour Modification Intervention Toolbox).4
This paper explores some of the lessons learnt from the PREVIEW study group sessions and using PREMIT, held at the University of Sydney.
Lessons learnt from the PREVIEW study
Total diet replacement diets for weight loss and motivation
Rapid weight loss is highly motivating for this group of people, some of whom had previously found it difficult to lose weight.5 It is a time to reflect on the implications of a diagnosis of pre-diabetes and develop the participant’s confidence that weight loss and introducing exercise will have an impact on their health outcomes (self-efficacy). The weight loss phase consisted of a total diet replacement (TDR) (3400 – 3800 kJ (810-910 kcal), also known as a low-energy or very low-energy formula diet) with 300g non- starchy vegetables for eight weeks. Over this time there were fortnightly workshops combined with weight and diet compliance. This was an ideal opportunity for people to develop a routine and review their diet and exercise habits. The diet of shakes, soups and porridges meant that some of the people re-discovered vegetables as they provided texture, crunch and variety. In our Sydney cohort, people noticed unhelpful habits: for example, afternoon snacks and social interactions that relied heavily on eating and drinking. Across all centres at the end of the weight loss phase the average weight loss was 10.3 +/- 2.8% for women and 11.8 +/- 3.5% for men6. During this phase, people had started to notice physical changes e.g. better sleep patterns, increased energy and an increased ability to move. This period should not be overlooked with respect to starting to introduce behaviour change strategies, a kind of “environmental audit”.
Group sessions for support
The group sessions in Sydney were held in the evenings with, the group size ranging from 15-20 people per group. On average there was a 1-hour session delivered by a dietitian and 1-hour by an exercise physiologist. Group members provided support to each other, often working together to solve problems and remind each other of past successes. There were variable ages in the groups which provided a ‘life-stage’ perspective on some of the difficulties or barriers participants faced. They experienced the challenges posed by the meal replacements, the joy of significant weight loss and the challenges of weight maintenance. It is important to develop social support network within the groups. This allowed the discussion of challenging external social interactions and problem solving e.g. a partner who is not supportive of the dietary changes they are wanting to make.
Over time the presenters transitioned from providing information to a facilitator role, which helped to develop the group member’s confidence and accountability. As the ‘plan-perform-evaluate’ cycle became routine, people were able to review their goals without input from the presenter and other group members were able to make suggestions. This helped to give people confidence to re-evaluate. Often clinic visits were a reminder for people to review their progress.
Specific behaviour change program – PREMIT
The behaviour change program (PREMIT4) consisted of four stages: preliminary, preparation, action and adherence. As people move through the stages, their confidence and skills developed. Participants were introduced to a range of behaviour change skills and were encouraged to adopt skills they felt comfortable with e.g. self-monitoring.
The preliminary stage coincided with the TDR weight loss phase. This was a time to provide information on their diagnosis to promote self-efficacy, reflect on past successes and conduct an environmental audit. It is a stage when people are losing weight and feeling inspired about making lifestyle changes.
The preparation phase covered the introduction of the diet and exercise prescription. Participants were encouraged to set goals e.g. plan, perform and evaluate cycle to monitor diet and exercise routine. Many realised that if they introduced a single change e.g. drinking water at every meal, they were more likely to form habits. Over the duration of the study there were participants who initially made changes to their diet and when they felt they had good eating habits in place, then addressed their exercise goals. Too many changes at once were confusing or overwhelming.
During the action phase, the visits were less frequent and people experienced barriers to maintaining their healthy diet and lifestyle habits. They were encouraged to use their goal setting techniques to review barriers and set new goals.
The final stage of the program was the adherence stage. This stage reinforces everything learnt combined with specific skills e.g. mindfulness-recognising hunger, managing lapses and relapses. One of the most important workshops was on relapse prevention and accepting lapses as part of life. For many participants accepting e lapses allowed them to prepare for this and readjust their behaviour. Many of the participants also experienced major changes in their life e.g. retirement, changing jobs, death and illnesses in the family and while circumstances do challenge your healthy lifestyle, they could be overcome.
Throughout the program participants were encouraged to review their goals and identify barriers. By the end of the study participants used diet tracking apps (MyFitnessPal, EasyDietDiary), the PREVIEW study tick box system and activity monitoring devices or measuring their own heart rates. Towards the end of the three-year intervention many of the participants revised past workshop material. For this reason, it is important to encourage them to keep the information together systematically.
Medical and social support
Participants in the study did not have individualised consultations with medical doctors. However, throughout the study there were regular visits to our research clinic where blood pressure, bone density, blood glucose measurements (as part of a 2 hour oral glucose tolerance test), monitoring of medications and general health were recorded. If there were any significant changes, it was discussed with the participants and their general practitioner was notified.
The number of group visits decreased in frequency over the three years – there were 13 sessions in the first year and only four in the next 24 months. Anecdotal feedback from participants here in Sydney is that they missed the regular contact and accountability. When the group session frequency dropped off contact was supplemented with study newsletters relating to the change of season, diet tips, recipes, exercise and the study progress, including publications. Regular email correspondence was maintained.
With increasing rates of obesity, there is a need to provide weight loss options in primary care. In the PREVIEW study, worldwide participants lost on average 11% of their original weight in the first 8-week weight loss phase using TDR products. A similar weight loss study in a population diagnosed with T2D, the Diabetes Remission Clinical Trial (DIRECT) study7 used a TDR for 3-5 months with a goal of 15 kg weight loss in a routine primary care environment. DIRECT used a behaviour change program called the Counterweight Program which consisted of monthly individual or group sessions. The investigators reported that half of the participants on the TDR were in remission at 12 months, implying that this kind of intervention can be effective in this setting.
The PREVIEW Consortium, Shannon Brodie, the PREVIEW Team and PREVIEW Study participants at the University of Sydney.
Global Report on Diabetes. WHO 2016 ISBN 978 92 4 156525 72.
Khaodhiar L, Cummings S, Apovian CM. Treating Diabetes and prediabetes by focusing on obesity management. Curr Diab Rep 2009 9(5): 348-3543.
Fogelholm M, Larsen TM, Westerterp-Plantenga M, et al. PREVIEW: Prevention of Diabetes through Lifestyle Intervention and Population Studies in Europe and around the World. Design, Methods, and Baseline Participant Description of an Adult Cohort Enrolled into a Three-Year Randomised Clinical Trial. Nutrients 2017 Jun 20;9(6). pii: E632. doi: 10.3390/nu9060632.4.
Kahlert D, Unyi-Reicherz A, Stratton G, et al. PREVIEW behaviour modification intervention toolbox (PREMIT): a study protocol for a psychological element of a multicentre project. Front Psychol. 2016:7;11365.
Huttunen-Lenz M, Hansen S, Christensen P et al. Psychol. PREVIEW study-influence of a behaviour modification intervention (PREMIT) in over 2300 people with pre-diabetes: intention, self-efficacy and outcome expectancies during the early phase of a lifestyle intervention. Res Behav Manag 2018 Sep 12:11:383-394. Doi:10.2147/PRBM.S160355.ecollection 2018 PubMed PMID: 30254498; PubMed Central PMCID:PMC6143124.6.
Christensen P, Meinert Larsen T, Westerterp-Plantenga M, et al. Men and women respond differently to rapid weight loss: Metabolic outcomes of a multi-centre intervention study after a low-energy diet in 2500 overweight, individuals with pre-diabetes (PREVIEW). Diabetes Obes Metab. 2018 Aug 7. doi: 10.1111/dom.13466.7.
Lean M, Brosnahan N, McLoone P, et al. Feasibility and indicative results from a 12-month low-energy liquid diet treatment and maintenance programme for severe obesity. Br J Gen Pract 2013; DOI:10.3399/bjgp13X6630738.
Huttunen-Lenz M, Hansen S, Meinert Larsen T, et al. The PREVIEW Study: Supporting Behaviour change in an international study among participants with pre-diabetes. Eur J of Health Psychol 26(1) 2019 p10-20