None listed
Conditions
Brief summary
In 2015 at least 10.9% of pregnant women in Australia were diagnosed with gestational diabetes (GDM) (1, 2). GDM creates risk of complications to both mother and baby during pregnancy, labour and delivery, and although GDM usually disappears shortly after birth, the mother remains at high risk for developing Type 2 Diabetes (T2DM) in the future (3). The health risks and complications associated with T2DM are well known and include development of other chronic diseases including cardiovascular disease (CVD), heart attack, stroke and kidney disease making diabetes a major health concern in Australia and globally (4). Lifestyle interventions involving diet and/or exercise that result in weight loss can reduce the risk of developing T2DM (5), however research has shown weight loss is not easily achieved or maintained (6-8). Keeping women engaged in a weight loss program can be difficult when they have a baby or young children to care for given the time constraints and lifestyle adjustments associated with looking after their children (9). Intermittent Energy Restriction (IER) is a form of calorie restriction which requires periods of severe calorie restriction or fasting) followed by periods of non-restricted eating each week. Previous research shows IER can result in weight loss at a comparable rate to daily energy restriction (10, 11). This study will test if the IER diet strategy commonly known as ‘the 5:2 diet’ provides a suitable regime for women with a history of GDM who have a young family at home by creating less burden and interruption to daily life by restricting energy intake for short periods and advising usual but not excessive eating the rest of the week. This will be the first study that examines an IER pattern for weight loss and T2DM prevention following GDM. Results from this PhD have the potential to benefit Australian women and families by improving their health and potentially reducing the financial burden associated with diabetes to individuals and the community. References 1. National Diabetes Services Scheme. NDSS Data Snapshots December 2015 2015 [20/06/2017]. Available from: https://static.diabetesaustralia.com.au/s/fileassets/diabetes-australia/2fdff38c-078e-4e76-8dee-8a5bdcf07ae8.pdf. 2. Australian Bureau of Statistics. 3301.0 - Births, Australia, 2015, Summary of Statistics for Australia 2016 [Available from: http://www.abs.gov.au/ausstats/abs@.nsf/mf/3301.0. 3. Bellamy L, Casas JP, Hingorani AD, Williams D. Type 2 diabetes mellitus after gestational diabetes: a systematic review and meta-analysis. Lancet (London, England). 2009;373(9677):1773-9. 4. Baker IDI Heart & Diabetes Institute, Diabetes Australia, Juvenile Diabetes Research Foundation. Diabetes: the silent pandemic and its impact on Australia. 2012:27. 5. Ratner RE, Christophi CA, Metzger BE, Dabelea D, Bennett PH, Pi-Sunyer X, et al. Prevention of diabetes in women with a history of gestational diabetes: effects of metformin and lifestyle interventions. The Journal of clinical endocrinology and metabolism. 2008;93(12):4774-9. 6. Morton S, Kirkwood S, Thangaratinam S. Interventions to modify the progression to type 2 diabetes mellitus in women with gestational diabetes: a systematic review of literature. Current opinion in obstetrics & gynecology. 2014;26(6):476-86. 7. Guo J, Chen J-L, Whittemore R, Whitaker E. Postpartum lifestyle interventions to prevent type 2 diabetes among women with history of gestational diabetes: A systematic review of randomized clinical trials. J Women's Health. 2016;25(1):38-49. 8. Peacock AS, Bogossian F, McIntyre HD, Wilkinson S. A review of interventions to prevent type 2 diabetes after gestational diabetes. Journal of the Australian College of Midwives. 2014;27(4):e7-e15. 9. Amorim AR, Linne YM, Lourenco PM. Diet or exercise, or both, for weight reduction in women after childbirth. Cochrane Database Syst Rev. 2007(3):Cd005627. 10. Davis CS, Clarke RE, Coulter SN, Rounsefell KN, Walker RE, Rauch CE, et al. Intermittent energy restriction and weight loss: a systematic review. Eur J Clin Nutr. 2016;70(3):292-9. 11. Headland M, Clifton PM, Carter S, Keogh JB. Weight-loss outcomes: A systematic review and meta-analysis of intermittent energy restriction trials lasting a minimum of 6 months. Nutrients. 2016;8(6):08.
Interventions
A 12 month randomised control study will be conducted. Participants randomised to the intermittent energy restriction (IER) group will be required to follow a very low energy diet of 2100kJ (500kCal) for two days per week and allowed ad libitum eating for the other five days per week. They may choose any days of the week for their ‘fasting’ days based on their individual preferences and will be encouraged to eat sensibly on their non-fasting days. Participants will receive education and written
A 12 month randomised control study will be conducted. Participants randomised to the intermittent energy restriction (IER) group will be required to follow a very low energy diet of 2100kJ (500kCal) for two days per week and allowed ad libitum eating for the other five days per week. They may choose any days of the week for their ‘fasting’ days based on their individual preferences and will be encouraged to eat sensibly on their non-fasting days. Participants will receive education and written information developed by the study Dietitian on how to adhere to the fasting days, information on calorie content of foods and sample meal plans for the 2100kJ days also developed by the study Dietitian. Women who are breastfeeding will be allowed extra calorie allowance of up to 2100kJ per day to allow for the energy cost of human milk production and the study dietitian will advise protein intake of 67g per day, adequate hydration and advise that fasting days must not be consecutive. Additionally, breastfeeding mothers will be required to weigh themselves weekly (scales will be provided) to ensure that weight loss does not exceed 0.5kg per week. These participants will have fortnightly follow up with the study Dietitian via phone call, email or university visit if needed for the first 3 months then a minimum of monthly follow up through email, phone call or university visit while they continue to breastfeed. Phone calls or visits would take between five and fifteen minutes. Participants will attend the clinic on 7 occasions over the 12 months (baseline, 1, 2 3,6, 9 and 12 months). At each visit they will be seen by the study dietitian who will check their compliance with the diet through diet checklists, weigh the participant and answer any questions. Weight will be taken at every visit. CSIRO Healthy Eating Score survey and a physical activity survey (Active Australia survey) and a sleep quality questionnaire (Pittsburgh Sleep Quality index) will be administered at baseline, 3, 6 and 12 months. Fasting blood samples will be taken on three occasions (baseline, 3 and 12 months) and will test fasting glucose, fasting insulin. HbA1C and fasting glucose will be measured by finger prick analysis at baseline, 3, and 12 months . A 2-hr oral glucose tolerance test (OGTT) will also be administered at baseline and 12 months, this will be done by using whole capillary blood via finger prick analysis with a glucometer. Visits to the clinic at baseline and 12 months will take between 2.25 and 2.5 hours due to the 2 hour OGTT. All other visits (1,2,3,6 and 9 months) will take 15-20 minutes. Women who achieve a weight loss of 7% of their body weight or reach a BMI of 21kg/m2 will be asked to maintain their body weight and be given advice on how to do this. Participants will be encouraged to meet physical activity recommendations of 30 minutes moderate physical activity per day on most days of the week.
Sponsors
University of South Australia
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
- Age 18 years or over - Diagnosed with gestational diabetes (GDM) by a medical professional during a pregnancy - BMI greater than or equal to 25kg/m2 - Not taking any diabetes medication including metformin
Exclusion criteria
Diagnosed with diabetes either prior to their GDM pregnancy or have developed diabetes since their GDM pregnancy. - Pregnant or less than 12 weeks post partum - Previous surgery for weight loss - Participating in any other diets or clinical studies involving medical or lifestyle interventions - Have been following the 5:2 diet in the last 3 months - non-English speaking -Current diagnosis of an eating disorder - Any other significant illness or disease
Outcome results
None listed