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REduced-Carbohydrate intervention for managing Obesity and Reduction of gestational Diabetes (RECORD): A randomized controlled feasibility trial.
Michalopoulou, M, Jebb, SA, MacKillop, LH, Dyson, P, Hirst, JE, Zhu, S, Wire, A, Astbury, NM
Diabetes, obesity & metabolism. 2024;(4):1407-1420
Abstract
AIM: To test the feasibility and acceptability of a reduced-carbohydrate dietary program, intended to reduce the risk of gestational diabetes. MATERIALS AND METHODS Fifty-one pregnant women at <20 weeks' gestation, with body mass index ≥30 kg/m2 , and a normal baseline oral glucose tolerance test (OGTT), were randomized 2:1 to an intervention or control group and followed-up until delivery. The dietary intervention aimed at providing 130-150 g carbohydrate/day. Feasibility outcomes assessed at 24-28 weeks' gestation, included adoption of the reduced-carbohydrate diet by the intervention group, and retention of all participants, assessed by completion of a second OGTT. Changes in glycemia, weight gain and dietary intake, and the maternal and neonatal outcomes were also assessed. Participants were interviewed about their experience of the intervention and the study. RESULTS Forty-nine of 51 participants attended the follow-up OGTT, a retention rate of 96% (95% confidence interval [CI] 86.8%-98.9%). In the intervention group, carbohydrate intake at follow-up was 190.4 (95% CI 162.5-215.6) g/day, a reduction of -24.6 (95% CI -51.5-2.4) g/day from baseline. Potentially favourable effects of the intervention on glucose control, weight gain and blood pressure were observed, but the study was not powered to detect significant differences in these. Participants found the intervention acceptable, and were content with the study processes, but some reported barriers to sustained adherence, mainly pertaining to competing priorities. CONCLUSIONS Retention was high, suggesting the study processes are feasible, but the carbohydrate reduction in the intervention group was small, and did not meet progression criteria, limiting the likelihood of achieving the desired goal to prevent gestational diabetes. TRIAL REGISTRATION NUMBER ISRCTN16235884.
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A systematic review of economic evaluations of interventions targeting childhood overweight and obesity.
Onyimadu, O, Violato, M, Astbury, NM, Hüls, H, Heath, L, Shipley, A, Taylor, H, Wilkins, LE, Abhari, RE, Jebb, SA, et al
Obesity reviews : an official journal of the International Association for the Study of Obesity. 2023;(9):e13597
Abstract
This systematic review critically appraised and synthesized evidence from economic evaluations of interventions targeting childhood excess weight. We conducted systematic searches in 11 databases from inception to April 19, 2023. Studies were eligible if they evaluated interventions targeting children up to 18 years and the study intervention(s) targeted childhood excess weight or sought to improve diet or physical activity, regardless of the type of economic evaluation or the underpinning study design. We synthesized evidence using narrative synthesis methods. One-hundred fifty-one studies met the eligibility criteria and were classified into three groups based on the intervention approach: prevention-only (13 studies), prevention and treatment (100 studies), and treatment-only (38 studies). The predominant setting and study design differed considerably between the three groups of studies. However, compared with usual care, most interventions were deemed cost-effective. The study participants' ages, sex, and socioeconomic status were crucial to intervention cost-effectiveness. Interventions whose effects were projected beyond childhood, such as bariatric surgery, lower protein infant formula, and home-based general practitioner consultations, tended to be cost-effective. However, cost-effectiveness was sensitive to the assumptions underlying the persistence and intensity of such effects. Our findings can inform future recommendations on the conduct of economic evaluations of interventions targeting childhood overweight and obesity, as well as practice and policy recommendations.
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Use of Cognitive and Behavioral Strategies During a Weight Loss Program: A Secondary Analysis of the Doctor Referral of Overweight People to Low-Energy Total Diet Replacement Treatment (DROPLET) Trial.
Henry, JA, Astbury, NM, Hartmann-Boyce, J, Koshiaris, C, Jebb, SA
Journal of the Academy of Nutrition and Dietetics. 2023;(10):1417-1428.e17
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BACKGROUND Achieving a sustained energy deficit is essential for weight loss, but the cognitive and behavioral strategies that support this goal are unclear. OBJECTIVE The goal of this study was to investigate the number and type of cognitive and behavioral strategies used by participants who were enrolled in a 1-year weight loss trial and to explore associations between strategies and magnitude of weight loss at 3 months and 1 year. DESIGN The study is a secondary post-hoc exploratory analysis of data collected as part of the Doctor Referral of Overweight People to Low-Energy total diet replacement Treatment (DROPLET), a randomized controlled trial conducted in general practices in England, United Kingdom, between January 2016 and August 2017. PARTICIPANTS/SETTING This study involved 164 participants from both intervention and control groups of the DROPLET trial who completed the Oxford Food and Behaviours (OxFAB) questionnaire to assess the use of 115 strategies grouped into 21 domains used to manage their weight. INTERVENTIONS Participants were randomized to either a behavioral weight loss program involving 8 weeks total diet replacement (TDR) and 4 weeks of food reintroduction or a program delivered by a medical practice nurse over a 3-month period (usual care [UC]). MAIN OUTCOME MEASURES Weight was objectively measured at baseline, 3 months, and 1 year. Cognitive and behavioral strategies used to support weight loss were assessed using the OxFAB questionnaire at 3 months. STATISTICAL ANALYSIS PERFORMED Exploratory factor analysis was used to generate data-driven patterns of strategy use, and a linear mixed-effects model was used to examine associations between use of these patterns and weight change. RESULTS No evidence was found of a difference in the number of strategies (mean difference, 2.41; 95% confidence interval [CI], -0.83, 5.65) or the number of domains used (mean difference, -0.23; 95% CI, -0.69, 0.23) between the TDR group and the UC group. The number of strategies was not associated with weight loss at either 3 months (-0.02 kg; 95% CI, -0.11, 0.06) or 1 year (-0.05 kg; 95% CI, -0.14, 0.02). Similarly, the number of domains used was not associated with weight loss at 3 months (-0.02 kg; 95% CI, -0.53, 0.49) or 1 year (-0.07 kg; 95% CI, -0.60, 0.46). Factor analysis identified four coherent patterns of strategy use, identified as Physical Activity, Motivation, Planned Eating, and Food Purchasing patterns. Greater use of strategies in the Food Purchasing (-2.6 kg; 95% CI, -4.42, -0.71) and Planned Eating patterns (-3.20 kg; 95% CI, -4.94, -1.46) was associated with greater weight loss at 1 year. CONCLUSIONS The number of cognitive and behavioral strategies or domains used does not appear to influence weight loss, but the types of strategy appear of greater importance. Supporting people to adopt strategies linked to planned eating and food purchasing may aid long-term weight loss.
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Evidence of lifestyle interventions in a pregnant population with chronic hypertension and/or pre-existing diabetes: A systematic review and narrative synthesis.
Goddard, L, Patel, R, Astbury, NM, Tucker, K, McManus, RJ
Pregnancy hypertension. 2023;31:60-72
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Chronic hypertension complicates ≤5 % of pregnancies, and those entering pregnancy with a pre-existing diagnosis of diabetes has a global prevalence of between 0.5 % and 2.6 %. The aim of this study was to collate the evidence around lifestyle interventions during pregnancy for women with chronic hypertension and/or pre-existing diabetes (type 1 and type 2). This study is a systematic review and meta-analysis of nine randomised controlled trials. Results show lack of clarity and data on the effect of lifestyle interventions in pregnant women with chronic hypertension and/or pre-existing diabetes, thereby exposing key gaps in the literature. Authors conclude that there is a shortage of primary interventional studies examining the effect of lifestyle interventions in high-risk pregnant populations who enter pregnancy with chronic conditions.
Abstract
BACKGROUND Pregnant people with chronic hypertension, pre-existing diabetes or both are at high risk of developing cardiovascular disease. Lifestyle interventions play an important role in disease management in non-pregnant populations. AIM: To review the existing evidence of randomised controlled trials (RCTs) that examine lifestyle interventions in pregnant people with chronic hypertension and/or pre-existing diabetes. METHODS A systematic review and narrative synthesis was conducted. Five electronic databases were searched from inception to April 2021 for RCTs evaluating antenatal lifestyle interventions in people with chronic hypertension and/or pre-existing diabetes with outcomes to include weight or blood pressure change. RESULTS Nine randomised controlled trials including 7438 pregnant women were eligible. Eight studies were mixed pregnant populations that included women with chronic hypertension and/or pre-existing diabetes. One study included only pregnant women with pre-existing diabetes. Intervention characteristics and procedures varied and targeted diet, physical activity and/or gestational weight. All studies reported weight and one study reported blood pressure change. Outcome data were frequently unavailable for the subset of women of interest, including subgroup data on important pregnancy and birth complications. Eligibility criteria were often ambiguous and baseline data on chronic hypertension was often omitted. CONCLUSION A lack of primary interventional trials examining the effect of lifestyle interventions on weight and blood pressure outcomes in pregnant populations with chronic hypertension and/or pre-existing diabetes was evident. Lifestyle modification has the potential to alter disease progression. Future trials should address the ambiguity and frequent exclusion of these important populations.
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Dietary interventions in pregnancy for the prevention of gestational diabetes: a literature review.
Michalopoulou, M, Jebb, SA, Astbury, NM
The Proceedings of the Nutrition Society. 2023;:1-13
Abstract
The aim of this review is to provide an overview of dietary interventions delivered during pregnancy for the prevention of gestational diabetes mellitus (GDM). GDM increases the risk of adverse pregnancy and neonatal outcomes, and also increases future cardiometabolic risks for both the mother and the offspring. Carrying or gaining excessive weight during pregnancy increases the risk of developing GDM, and several clinical trials in women with overweight or obesity have tested whether interventions aimed at limiting gestational weight gain (GWG) could help prevent GDM. Most dietary interventions have provided general healthy eating guidelines, while some had a specific focus, such as low glycaemic index, increased fibre intake, reducing saturated fat or a Mediterranean-style diet. Although trials have generally been successful in attenuating GWG, the majority have been unable to reduce GDM risk, which suggests that limiting GWG may not be sufficient in itself to prevent GDM. The trials which have shown effectiveness in GDM prevention have included intensive face-to-face dietetic support, and/or provision of key foods to participants, but it is unclear whether these strategies could be delivered in routine practice. The mechanism behind the effectiveness of some interventions over others remains unclear. Dietary modifications from early stages of pregnancy seem to be key, but the optimum dietary composition is unknown. Future research should focus on designing acceptable and scalable dietary interventions to be tested early in pregnancy in women at risk of GDM.
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Development and testing of a reduced carbohydrate intervention for the management of obesity and reduction of gestational diabetes (RECORD): protocol for a feasibility randomised controlled trial.
Michalopoulou, M, Jebb, SA, MacKillop, LH, Dyson, P, Hirst, JE, Wire, A, Astbury, NM
BMJ open. 2022;(9):e060951
Abstract
INTRODUCTION Previous trials of dietary interventions to prevent gestational diabetes mellitus (GDM) have yielded only limited success. Low-carbohydrate diets have shown promise for the treatment of type 2 diabetes, but there is no evidence to support their use in pregnancy. The aim of this study is to explore the feasibility of a moderately reduced-carbohydrate dietary intervention delivered from mid-pregnancy alongside routine antenatal care. METHODS AND ANALYSIS This is a feasibility randomised controlled trial (RCT) with embedded qualitative study. Sixty women who are pregnant <20 weeks' gestation, with body mass index ≥30 kg/m2 at their antenatal booking appointment, will be randomised 2:1 intervention or control (usual care) and followed up until delivery. The intervention is a moderately reduced-carbohydrate diet (~130-150 g total carbohydrate/day), designed to be delivered alongside routine antenatal appointments. Primary outcomes are measures of adoption of the diet and retention of participants. Secondary outcomes include incidence of GDM, change in markers of glycaemic control, gestational weight gain, total carbohydrate and energy intake. Process outcomes will examine resources and management issues. Exploratory outcomes include further dietary changes, quality of life, maternal and neonatal outcomes, and qualitative measures. ETHICS AND DISSEMINATION This trial was reviewed and approved by the South-Central Oxford B Research Ethics Committee NHS National Research Ethics Committee and the Health Research Authority (Reference: 20/SC/0442). The study results will inform whether to progress to a full-scale RCT to test the clinical effectiveness of the RECORD programme to prevent GDM in women at high risk. The findings will be published in peer-reviewed journals and presented at conferences. TRIAL REGISTRATION NUMBER ISRCTN16235884.
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Associations between body composition, fat distribution and metabolic consequences of excess adiposity with severe COVID-19 outcomes: observational study and Mendelian randomisation analysis.
Gao, M, Wang, Q, Piernas, C, Astbury, NM, Jebb, SA, Holmes, MV, Aveyard, P
International journal of obesity (2005). 2022;(5):943-950
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BACKGROUND Higher body mass index (BMI) and metabolic consequences of excess weight are associated with increased risk of severe COVID-19, though their mediating pathway is unclear. METHODS A prospective cohort study included 435,504 UK Biobank participants. A two-sample Mendelian randomisation (MR) study used the COVID-19 Host Genetics Initiative in 1.6 million participants. We examined associations of total adiposity, body composition, fat distribution and metabolic consequences of excess weight, particularly type 2 diabetes, with incidence and severity of COVID-19, assessed by test positivity, hospital admission, intensive care unit (ICU) admission and death. RESULTS BMI and body fat were associated with COVID-19 in the observational and MR analyses but muscle mass was not. The observational study suggested the association with central fat distribution was stronger than for BMI, but there was little evidence from the MR analyses than this was causal. There was evidence that strong associations of metabolic consequences with COVID-19 outcomes in observational but not MR analyses. Type 2 diabetes was strongly associated with COVID-19 in observational but not MR analyses. In adjusted models, the observational analysis showed that the association of BMI with COVID-19 diminished, while central fat distribution and metabolic consequences of excess weight remained strongly associated. In contrast, MR showed the reverse, with only BMI retaining a direct effect on COVID-19. CONCLUSIONS Excess total adiposity is probably casually associated with severe COVID-19. Mendelian randomisation data do not support causality for the observed associations of central fat distribution or metabolic consequences of excess adiposity with COVID-19.
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Extended follow-up of a short total diet replacement programme: results of the Doctor Referral of Overweight People to Low Energy total diet replacement Treatment (DROPLET) randomised controlled trial at 3 years.
Astbury, NM, Edwards, RM, Ghebretinsea, F, Shanyinde, M, Mollison, J, Aveyard, P, Jebb, SA
International journal of obesity (2005). 2021;(11):2432-2438
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OBJECTIVES To test the long-term effectiveness of a total diet replacement programme (TDR) for routine treatment of obesity in a primary care setting. METHODS This study was a pragmatic, two-arm, parallel-group, open-label, individually randomised controlled trial in adults with obesity. The outcomes were change in weight and biomarkers of diabetes and cardiovascular disease risk from baseline to 3 years, analysed as intention-to-treat with mixed effects models. INTERVENTIONS The intervention was TDR for 8 weeks, followed by food-reintroduction over 4 weeks. Behavioural support was provided weekly for 8 weeks, bi-weekly for the next 4 weeks, then monthly for 3 months after which no further support was provided. The usual care (UC) group received dietary advice and behavioural support from a practice nurse for up to 3 months. RESULTS Outcome measures were collected from 179 (66%) participants. Compared with baseline, at 3 years the TDR group lost -6.2 kg (SD 9.1) and usual care -2.7 kg (SD 7.7); adjusted mean difference -3.3 kg (95% CI: -5.2, -1.5), p < 0.0001. Regain from programme end (6 months) to 3 years was greater in TDR group +8.9 kg (SD 9.4) than UC + 1.2, (SD 9.1); adjusted mean difference +6.9 kg (95% CI 4.2, 9.5) P < 0.001. At 3 years TDR led to greater reductions than UC in diastolic blood pressure (mean difference -3.3 mmHg (95% CI:-6.2; -0.4) P = 0.024), and systolic blood pressure (mean differences -3.7 mmHg (95% CI: -7.4; 0.1) P = 0.057). There was no evidence of differences between groups in the change from baseline to 3 years HbA1c (-1.9 mmol/mol (95% CI: -0.7; 4.5; P = 0.15), LDL cholesterol concentrations (0.2 mmol/L (95% CI -0.3, 0.7) P = 0.39), cardiovascular risk score (QRISK2) (-0.37 (95% CI -0.96; 0.22); P = 0.22). CONCLUSIONS Treatment of people with obesity with a TDR programme compared with support from a practice nurse leads to greater weight loss which persists to at least 3 years, but there was only evidence of sustained improvements in BP and not in other aspects of cardiometabolic risk.
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Testing the short-term effectiveness of primary care referral to online weight loss programmes: A randomised controlled trial.
Noreik, M, Madigan, CD, Astbury, NM, Edwards, RM, Galal, U, Mollison, J, Ghebretinsea, F, Jebb, SA
Clinical obesity. 2021;(6):e12482
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Abstract
Guidelines ask health professionals to offer brief advice to encourage weight loss for people living with obesity. We tested whether referral to one of three online programmes could lead to successful weight loss. A total of 528 participants aged ≥18 years with a body mass index of ≥30 kg/m2 were invited via a letter from their GP. Participants were randomised to one of three online weight loss programmes (NHS Weight Loss Plan, Rosemary Online or Slimming World Online) or to a control group receiving no intervention. Participants self-reported weight at baseline and 8 weeks. The primary outcome was weight change in each of the active intervention groups compared with control. We also compared the proportion of participants losing ≥5% or ≥10% of body weight. For Rosemary, Online mean weight loss was modestly greater than control (-1.5 kg [95% confidence interval (CI) -2.3 to -0.6]) and more than three times as many participants in this group lost ≥5% (relative risk [RR] = 3.64, 95% CI: 1.63-8.1). For Slimming World, mean weight loss was not significantly different from control (-0.8 kg [95%CI -1.7 to 0.1]), twice as many participants lost ≥5% (RR = 2.70, 1.17-6.23). There was no significant difference in weight loss for participants using the NHS Weight Loss Plan (-0.4 kg, [95% CI -1.3 to 0.5]), or the proportion losing ≥5% (RR = 2.09, 0.87-5.01). Only one of three online weight loss programmes was superior to no intervention and the effect size modest among participants living with obesity.
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Evaluation of an intervention to provide brief support and personalized feedback on food shopping to reduce saturated fat intake (PC-SHOP): A randomized controlled trial.
Piernas, C, Aveyard, P, Lee, C, Tsiountsioura, M, Noreik, M, Astbury, NM, Oke, J, Madigan, C, Jebb, SA
PLoS medicine. 2020;(11):e1003385
Abstract
BACKGROUND Guidelines recommend reducing saturated fat (SFA) intake to decrease cardiovascular disease (CVD) risk, but there is limited evidence on scalable and effective approaches to change dietary intake, given the large proportion of the population exceeding SFA recommendations. We aimed to develop a system to provide monthly personalized feedback and healthier swaps based on nutritional analysis of loyalty card data from the largest United Kingdom grocery store together with brief advice and support from a healthcare professional (HCP) in the primary care practice. Following a hybrid effectiveness-feasibility design, we tested the effects of the intervention on SFA intake and low-density lipoprotein (LDL) cholesterol as well as the feasibility and acceptability of providing nutritional advice using loyalty card data. METHODS AND FINDINGS The Primary Care Shopping Intervention for Cardiovascular Disease Prevention (PC-SHOP) study is a parallel randomized controlled trial with a 3 month follow-up conducted between 21 March 2018 to 16 January2019. Adults ≥18 years with LDL cholesterol >3 mmol/L (n = 113) were recruited from general practitioner (GP) practices in Oxfordshire and randomly allocated to "Brief Support" (BS, n = 48), "Brief Support + Shopping Feedback" (SF, n = 48) or "Control" (n = 17). BS consisted of a 10-minute consultation with an HCP to motivate participants to reduce their SFA intake. Shopping feedback comprised a personalized report on the SFA content of grocery purchases and suggestions for lower SFA swaps. The primary outcome was the between-group difference in change in SFA intake (% total energy intake) at 3 months adjusted for baseline SFA and GP practice using intention-to-treat analysis. Secondary outcomes included %SFA in purchases, LDL cholesterol, and feasibility outcomes. The trial was powered to detect an absolute reduction in SFA of 3% (SD3). Neither participants nor the study team were blinded to group allocation. A total of 106 (94%) participants completed the study: 68% women, 95% white ethnicity, average age 62.4 years (SD 10.8), body mass index (BMI) 27.1 kg/m2 (SD 4.7). There were small decreases in SFA intake at 3 months: control = -0.1% (95% CI -1.8 to 1.7), BS = -0.7% (95% CI -1.8 to 0.3), SF = -0.9% (95% CI -2.0 to 0.2); but no evidence of a significant effect of either intervention compared with control (difference adjusted for GP practice and baseline: BS versus control = -0.33% [95% CI -2.11 to 1.44], p = 0.709; SF versus control = -0.11% [95% CI -1.92 to 1.69], p = 0.901). There were similar trends in %SFA based on supermarket purchases: control = -0.5% (95% CI -2.3 to 1.2), BS = -1.3% (95% CI -2.3 to -0.3), SF = -1.5% (95% CI -2.5 to -0.5) from baseline to follow-up, but these were not significantly different: BS versus control p = 0.379; SF versus control p = 0.411. There were small reductions in LDL from baseline to follow-up (control = -0.14 mmol/L [95% CI -0.48, 0.19), BS: -0.39 mmol/L [95% CI -0.59, -0.19], SF: -0.14 mmol/L [95% CI -0.34, 0.07]), but these were not significantly different: BS versus control p = 0.338; SF versus control p = 0.790. Limitations of this study include the small sample of participants recruited, which limits the power to detect smaller differences, and the low response rate (3%), which may limit the generalisability of these findings. CONCLUSIONS In this study, we have shown it is feasible to deliver brief advice in primary care to encourage reductions in SFA intake and to provide personalized advice to encourage healthier choices using supermarket loyalty card data. There was no evidence of large reductions in SFA, but we are unable to exclude more modest benefits. The feasibility, acceptability, and scalability of these interventions suggest they have potential to encourage small changes in diet, which could be beneficial at the population level. TRIAL REGISTRATION ISRCTN14279335.
