Effectiveness Of Weight Management Interventions Research Articles

Weight loss following lifestyle modification interventions among adults with overweight and obesity in low- and middle-income countries – A systematic review and meta-analysis protocol

Introduction: Overweight and obesity have become complex public health issues affecting all age, gender, and socioeconomic groups. It is a significant risk factor for various noncommunicable diseases such as hypertension, liver and kidney disease, diabetes, cardiovascular diseases, and depression. Despite this, obesity screening, prevention, and treatment are insufficiently focused in the health systems in low- and middle-income countries. There is a need for targeted interventions that are more realistic, applicable to all population groups, and have the potential for higher success rates. With this idea in mind, the current review has focused on systematically gathering evidence on the effect of weight management interventions compared to the standard of care among adults with overweight and obesity from low- and middle-income countries. Methodology: We will systematically search four electronic databases – PubMed, Google Scholar, Embase, and the Cochrane Library from their inception until July 2023 for relevant studies. A combination of medical subject headings and free text terms will be used for carrying out literature searches. All the experimental studies randomized controlled trials or nonrandomized trials conducted in a clinic-, hospital-, or community-based setting will be included in our review. Studies conducted among adults aged 18 years and above with overweight or obesity with nonpharmacological weight management given as intervention and standard of care given as comparator will be looked for. The outcome measures include the standardized mean difference of weight, body mass index, waist or hip circumference, or odds ratio of obesity or overweight between the treatment groups. Meta-regression or subgroup analyses will be performed to explore the heterogeneity. The Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines will be used to report the review. Study Design: Systematic review and meta-analysis. Ethics and Dissemination: There are no ethical concerns about the conduct of this review. Evidence will be disseminated at relevant conferences and by submitting scientific articles to academic peer-reviewed journals. Conclusion: Findings from this systematic review will significantly contribute to enhancing knowledge about evidence of the effectiveness of various obesity management strategies. This evidence-based approach will guide informed decision-making processes and support the development of effective interventions or programs to address the obesity epidemic in low- and middle-income countries. Prospero Registration: CRD42022352118.

Conceptualizing weight management for night shift workers: A mixed-methods systematic review.

Shift workers have an increased risk of obesity and metabolic conditions. This mixed-methods systematic literature review on night shift workers aimed to: (1) identify barriers/enablers of weight management; (2) examine effectiveness of weight management interventions; and (3) determine whether interventions addressed enablers/barriers. Six databases were searched, articles screened by title/abstract, followed by full-text review, and quality assessment. Eligible qualitative studies documented experiences of behaviors related to weight change. Eligible quantitative studies were behavior change interventions with weight/body mass index outcomes. A thematic synthesis was undertaken for qualitative studies using the social-ecological model (SEM). Interventions were synthesized narratively including: weight/body composition change; components mapped by behavior change taxonomy; and SEM. A synthesis was undertaken to identify if interventions addressed perceived enablers/barriers. Eight qualitative (n = 169 participants) and 12 quantitative studies (n = 1142 participants) were included. Barriers predominated discussions: intrapersonal (time, fatigue, stress); interpersonal (work routines/cultural norms); organizational (fatigue, lack of: routine, healthy food options, breaks/predictable work); community (lack of healthy food options). The primary outcome for interventions was not weight loss and most did not address many identified enablers/barriers. One intervention reported a clinically significant weight loss result. Weight loss interventions that address barriers/enablers at multiple SEM levels are needed.

Characteristics associated with successful treatment outcome in children with overweight and obesity at a tertiary care clinic in Sri Lanka

Background: Lack of response to childhood obesity management programmes is a global concern. Western studies show that the age and the body mass index of the child at the commencement of the treatment, frequency of clinic visits and parental level of education affect the outcome of such treatment programmes.Objectives: To identify factors associated with z-BMI reduction in children with overweight or obesity who underwent a 6-month clinic-based obesity management programme.Methods: A retrospective analysis of medical records was carried out on children between 2 and 15 years of age who had undergone a weight management programme of 6 months duration at the Teaching Hospital, Peradeniya between 2017 and 2020. Reduction in z-BMI was considered as the successful treatment outcome. Anthropometric, demographic and lifestyle factors at the first and the last visits were extracted and described using means with 95% confidence intervals. Adherence to treatment was evaluated under the categories of diet, physical activity and behavioural modification. Logistic regression was applied to create a model that explains the effect on the treatment outcome.Results: Out of 401 subjects, 94 (23.44%) completed follow up. Eighty subjects (85.1%) achieved a mean z-BMI reduction of 1.981±0.584.The Logistic regression returned a model with screen time as the only statistically significant explanatory variable for changes in BMI. Compared to no screen time those with screen times of over 4 hours were 5.85 (CI 1.25 – 27.28) times more likely to have a negative response.Conclusion: Strategies to minimize screen time are needed to enhance the effectiveness of weight management interventions.

Differential effects of diet and physical activity interventions in pregnancy to prevent gestational diabetes mellitus and reduce gestational weight gain by level of maternal adiposity: a protocol for an individual patient data (IPD) meta-analysis of randomised controlled trials

IntroductionWomen and their infants are at increased risk of complications if gestational diabetes mellitus (GDM) or excessive gestational weight gain (GWG) occurs in pregnancy. Weight management interventions in pregnancy, consisting...

Effectiveness of weight management interventions for adults delivered in primary care: systematic review and meta-analysis of randomised controlled trials

ObjectiveTo examine the effectiveness of behavioural weight management interventions for adults with obesity delivered in primary care.DesignSystematic review and meta-analysis of randomised controlled trials.Eligibility criteria for selection of studiesRandomised controlled...

Association between Telomere Length and Pediatric Obesity: A Systematic Review.

Objective: Telomere length (TL) is a robust marker of biological aging, and increased telomere attrition is noted in adults with obesity. The primary objective of this systematic review was to summarize current knowledge on the effects of childhood obesity in TL. The secondary objective was to assess the effect of weight management interventions in TL. Methods: The following databases were searched: PubMed, Scopus, Web of Science and Heal-link.gr from inception to September 2021. The search was performed using the following combinations of terms: “telomer*” [All Fields] AND (“length” [All Fields] OR “lengths” [All Fields]) AND “obes*” [All Fields] AND (“child*” [All Fields] OR “adolescen*” [All Fields]). Results: A total of 16 original articles were included in this systematic review. Eleven of them were cross-sectional and five were lifestyle interventions. Conclusions: There was a tendency towards a negative association between childhood obesity and TL. Life-style interventions in children have been associated with increased TL peripherally, indicating a possible association of the redistribution of younger cells in the periphery with the favorable effect of these interventions. Further prospective studies with larger sample sizes that employ other markers of cell aging would potentially elucidate this important mechanistic relation.

Awareness of personal height and weight among community-dwelling people in West New Britain Province, Papua New Guinea.

We investigated the accessibility of height- and weight-measurement tools and the awareness of one's own height and weight in a specific population in West New Britain Province (WNBP), Papua New Guinea, where obesity is prevalent. Of 558 participants (mean age 34.8 ± 14.0 years, 48.2% women, average body mass index =25.1 ± 4.83 kg/m2), >70% had limited access to measurement scales and 97.5% lacked accurate knowledge of their own height and weight. Our findings imply that increased access to measurement tools and awareness of personal height and weight is necessary to improve the feasibility and effectiveness of weight-management interventions in areas such as WNBP.

Does the built environment influence the effectiveness of behavioral weight management interventions?

Outcomes of behavioral lifestyle interventions for promoting weight loss vary widely across participants. The effectiveness of a weight management intervention may depend on a person's environmental context. This study compared short- and longer-term effects of a structured nationwide weight management program for people living in neighborhoods with different levels of walkability and different access to recreational places (parks, fitness facilities). Drawing on the health production model, we tested competing hypotheses for whether treatment effects of the program complement environmental supports or substitute for environmental constraints. We studied the US Department of Veterans Affairs (VA) MOVE! weight management program using VA electronic heath record data (2009–2014) and a difference-in-differences design with an inverse propensity score matched comparison group. A total of 114,256 program participants and 498,494 non-participants comprised the sample. Built environment features were measured within one-mile of each person's home. We estimated program effects on body mass index (BMI) for subgroups with different built environments at 6-, 12-, 18-, and 24-month follow-up using linear regressions with person and year fixed effects. At 6 months, the program reduced BMI by 0.4–0.6 kg/m2 among men and 0.3–0.5 kg/m2 among women. The effect diminished at 12, 18, and 24 months. The program effect did not vary significantly across subgroups with different walkability, park access, or fitness facility access. The MOVE! program was not sensitive to environmental context. Results did not lend support to either hypothesis that the MOVE! program complements or substitutes for a person's built environment to affect weight management outcomes.

Weight management interventions for youth with autism spectrum disorder: a systematic review.

In response to the elevated levels of overweight and obesity among children with autism spectrum disorder (ASD), this article provides a systematic review of the extant empirical literature reporting the effect of weight management interventions (including exercise, diet, and medication) for youth with ASD. A systematicreview of publishedstudies. The databases CINAHL, Web of Science, ERIC, Pubmed, and PsychINFO were searched, revealing 12 studies that were eligible for review. Of the included studies, half (n = 6) demonstrated significant weight loss; including comprehensive (n = 3), pharmaceutical (n = 2), and exercise (n = 1) interventions. Of relevance, and concern, was that only one of the included studies was determined to be of strong research quality, with the majority (n = 8) determined as being of weak study quality. Furthermore, studies included highly heterogeneous treatment approaches, study designs, and sample characteristics. This review demonstrates the potential of interventions (particularly individualized, comprehensive, and multidisciplinary team- based interventions) to effectively impact on weight among youth with ASD. It is imperative to rigorously test these interventions in individuals with ASD given the rates of obesity in this population and complications that ensue.

A retrospective review of patient outcomes in the pediatric HEROES weight management program

Pediatric obesity is a public health concern in the U.S. The purpose of this study was to describe the impact of a pediatric stage 3 and 4 weight management program. Program aims measured: change in biometric values using BMI z-scores; intervention attrition rate; and health-related quality of life (HRQOL) from admission through the initial six months of the program. The program evaluation included a retrospective review of 884 electronic records. Of the 698 children that met the inclusion criteria, 468 completed at least one follow-up visit within the baseline to 6 month time period. Overall 66.38% of the 468 maintained program involvement at the 6 month evaluation. Of the 468 who completed the 6 months, 192 children/families participated in the clinic only program and 276 participated both in the clinic and a 12 week contract education/fitness and exercise intervention. The completion rate for the contract intervention was 7.3%. All children demonstrated a decrease in BMI z-scores. There were no statistically significant differences (p = 0.276) in the BMI z-change scores from baseline to 6 months in the clinic only program; those who did not complete the education/fitness and exercise intervention, and those who completed the education/fitness and exercise intervention. Children demonstrated a statistically significant improvement in their overall HRQOL scale score (p = 0.001) from baseline to the 6 month evaluation. The results indicate the impact of attrition and HRQOL in weight management programs. Further research is needed to develop and strengthen the effectiveness of weight management interventions. Keywords: pediatric, obesity, weight management.

What behaviour change techniques are associated with effectiveness of weight management interventions? A systematic review of systematic reviews

What behaviour change techniques are associated with effectiveness of weight management interventions? A systematic review of systematic reviews

Measuring Factors Influencing Progression across the Stages of Readiness to Lose Weight among Overweight and Obese Adolescents

Epidemic incidence of obesity has become one of the public health priorities in disease control prevention. The study aims to determine the prevalence of readiness stages to lose weight among the overweight and obese adolescents and its influencing factors. A cross-sectional study was conducted on 631 adolescents of body mass index for age with z-score > 1 SD based on World Health Organization growth reference chart. The stages of readiness to lose weight were assessed using Trans-Theoretical Model. Intrinsic and extrinsic factors were collected using self-administered questionnaire. Majority of the respondents were in the action stage (40.3%) followed by contemplation (26.5%), preparation (15.5%), maintenance (11.4%) and pre-contemplation (6.3%). Ordinal regression analysis identified significant factors influencing progression across the stages of readiness to lose weight: no junk foods sold in school canteens (p = 0.005), TV viewing time ≤2 hours (p = 0.001), high physical activity means score (p < 0.001) and family encouragement on healthy eating (p = 0.010). Majority of adolescents who were overweight and obese were at the action stage of weight reduction. Focusing on extrinsic factors help to improve the effectiveness of weight management intervention.

Do weight management interventions delivered by online social networks effectively improve body weight, body composition, and chronic disease risk factors? A systematic review

Introduction Currently, no systematic review/meta-analysis has examined studies that used online social networks (OSN) as a primary intervention platform. Therefore, the purpose of this review was to evaluate the effectiveness of weight management interventions delivered through OSN. Methods PubMed, EMBASE, PsycINFO, Web of Science, and Scopus were searched (January 1990–November 2015) for studies with data on the effect of OSNs on weight loss. Only primary source articles that utilized OSN as the main platform for delivery of weight management/healthy lifestyle interventions, were published in English language peer-reviewed journals, and reported outcome data on weight were eligible for inclusion in this systematic review. Five articles were included in this review. Results One-hundred percent of the studies (n = 5) reported a reduction in baseline weight. Three of the five studies (60%) reported significant decreases in body weight when OSN was paired with health educator support. Only one study reported a clinical significant weight loss of ≥5%. Conclusion Using OSN for weight management is in its early stages of development and, while these few studies show promise, more research is needed to acquire information about optimizing these interventions to increase their efficacy.

The Impact of Racial and Socioeconomic Disparities on Binge Eating and Self-Efficacy among Adults in a Behavioral Weight Loss Trial.

The prevalence of obesity is a significant problem among racial and ethnic minorities and those of low socioeconomic status (SES). Psychosocial barriers, such as binge eating and low self-efficacy, are known to hinder the adoption of a more healthful diet. There is limited research identifying racial and SES differences in binge eating and self-efficacy. Further investigations of these constructs may allow researchers to improve the effectiveness of weight management interventions and increase social worker involvement. In this article, the authors examine the socioeconomic and racial differences in binge eating and eating self-efficacy in a sample of individuals seeking weight loss treatment (N = 151). They explore associations between various sociodemographic variables and the Binge Eating Scale and Weight Efficacy Lifestyle Questionnaire (WEL). At baseline, nonwhite participants or those with fewer years of education exhibited more confidence resisting eating when food was available. Moreover, nonwhite participants reported more self-confidence eating under social pressure and had higher total WEL scores than white participants. However, at six months, nonwhite participants' WEL scores decreased. White participants increased their total WEL scores and obtained a higher percent weight change by the end of the intervention. Additional investigations on the dynamics affecting the development of self-efficacy are warranted.

A single-blind, pilot randomised trial of a weight management intervention for adults with intellectual disabilities and obesity: study protocol.

BackgroundThe prevalence of obesity in adults with intellectual disabilities has consistently been reported to be higher than the general population. Despite the negative impact of obesity on health, there is little evidence of the effectiveness of weight management interventions for adults with intellectual disabilities and obesity. Preliminary results from a single-stranded feasibility study of a multi-component weight management intervention specifically designed for adults with intellectual disabilities and obesity (TAKE 5) and that satisfied clinical recommendations reported that it was acceptable to adults with intellectual disabilities and their carers. This study aims to determine the feasibility of a full-scale clinical trial of TAKE 5.MethodsThis study will follow a pilot randomised trial design. Sixty-six obese participants (body mass index (BMI) ≥30 kg/m2) will be randomly allocated to the TAKE 5 multi-component weight management intervention or a health education ‘active’ control intervention (Waist Winners Too (WWToo)). Both interventions will be delivered over a 12-month period. Participants’ anthropometric measures (body weight, BMI, waist circumference, percentage body fat); indicators of activity (levels of physical activity and sedentary behaviour) and well-being will be measured at three time points: baseline, 6 and 12 months. The researcher collecting outcome measures will be blind to study group allocation.ConclusionsThe data from this study will generate pilot data on the acceptability of randomisation, attrition rates and the estimates of patient-centred outcomes of TAKE 5, which will help inform future research and the development of a full-scale randomised clinical trial.Trial registration ISRCTN52903778.

The effect of weight management interventions that include a diet component on weight-related outcomes in pregnant and postpartum women: a systematic review protocol.

Review question/objective What are the effects of weight management interventions that include a diet component on weight-related outcomes in pregnant and postpartum women? The primary objective of this systematic review is to evaluate the effectiveness of weight management interventions which include a diet component and are aimed at limiting gestational weight gain and postpartum weight retention in women. The second objective of this systematic review is to investigate included intervention components with respect to effect on weight-related outcomes. This may include, but is not limited to: length of intervention, use of face-to-face counselling, group or individual consultations, use of other interventions components including exercise, use of goals and use of support tools like food diaries, coaching , including email or text message support. Inclusion criteria Types of participants Participants of interest are pregnant or post-partum adult females (18 years and over), from all pre-pregnancy BMI categories. Women will be included if they have co-morbidities of gestational diabetes or diabetes; all other medical conditions will be excluded. Types of interventions Studies will be included if the weight management interventions include a dietary component and have an objective of determining the relationship with antenatal and/or postpartum weight change. The interventions must have been conducted across the antenatal or postpartum period, with intervention initiation at any point up to six weeks after delivery. Interventions will be compared with usual care, wait-list controls or alternative intervention component or intensity. Types of outcomes This review will consider studies that include body weight as the primary outcome, measured either during pregnancy and/or postpartum. Weight change outcomes reported as weight (kg or lb), Body Mass Index, waist or hip circumference and/or percentage body fat will be included. Adverse outcomes will be documented if reported.

Impact of dietary macronutrient distribution on BMI and cardiometabolic outcomes in overweight and obese children and adolescents: a systematic review

The present systematic review examined the effectiveness of weight management interventions comparing diets with varying macronutrient distributions on BMI and cardiometabolic risk factors in overweight or obese children and adolescents. A systematic search of seven databases for the period 1975-2013 identified 14 eligible randomized or quasi-randomized controlled trials conducted with 6-18-year-old subjects. Seven trials compared a low-fat (≤ 33% energy or < 40 g/day) to an isocaloric (n = 2) or ad libitum (n = 5) low-carbohydrate diet (< 20% energy or < 60 g/day). Meta-analysis indicated a greater reduction in BMI in the low-carbohydrate group immediately after dietary intervention; however, the quality of the studies was limited and cardiometabolic benefits were inconsistent. Six trials compared increased-protein diets (19-30% energy) to isocaloric standard-protein diets (15-20% energy) and one compared an increased-fat diet (40% energy) to an isocaloric standard-fat diet (27% energy); there were no differences in outcomes in these studies. Current evidence suggests that improved weight status can be achieved in overweight or obese children and adolescents irrespective of the macronutrient distribution of a reduced-energy diet. Tailoring the macronutrient content to target specific cardiometabolic risk factors, such as a low-carbohydrate diet to treat insulin resistance, may be possible, but further research is needed before specific recommendations can be made.

The effectiveness of weight management interventions in breastfeeding women--a systematic review and critical evaluation.

The postpartum period is a vulnerable time for excess weight retention, particularly for the increasing number of women who are overweight at the start of their pregnancy and subsequently find it difficult to lose additional weight gained during pregnancy. Although postpartum weight management interventions play an important role in breaking this potentially vicious cycle of weight gain, the effectiveness of such interventions in breastfeeding women remains unclear. Our aim was to systematically review the literature about the effectiveness of weight management interventions in breastfeeding women. Seven electronic databases were searched for eligible papers. Intervention studies included were carried out exclusively in breastfeeding mothers, ≤2years postpartum and with a body mass index greater than 18.5kg/m(2) , with an outcome measure of change in weight and/or body composition. Six studies met the selection criteria, and were stratified according to the type of intervention and outcome measures. Despite considerable heterogeneity among studies, the dietary-based intervention studies appeared to be the most efficacious in promoting weight loss; however, few studies were tailored toward the needs of breastfeeding women. Weight management interventions which include an energy-restricted diet may play a key role in successful postpartum weight loss for breastfeeding mothers.

Weight management interventions in adults with intellectual disabilities and obesity: a systematic review of the evidence.

To evaluate the clinical effectiveness of weight management interventions in adults with intellectual disabilities (ID) and obesity using recommendations from current clinical guidelines for the first line management of obesity in adults. Full papers on lifestyle modification interventions published between 1982 to 2011 were sought by searching the Medline, Embase, PsycINFO and CINAHL databases. Studies were evaluated based on 1) intervention components, 2) methodology, 3) attrition rate 4) reported weight loss and 5) duration of follow up. Twenty two studies met the inclusion criteria. The interventions were classified according to inclusion of the following components: behaviour change alone, behaviour change plus physical activity, dietary advice or physical activity alone, dietary plus physical activity advice and multi-component (all three components). The majority of the studies had the same methodological limitations: no sample size justification, small heterogeneous samples, no information on randomisation methodologies. Eight studies were classified as multi-component interventions, of which one study used a 600 kilocalorie (2510 kilojoule) daily energy deficit diet. Study durations were mostly below the duration recommended in clinical guidelines and varied widely. No study included an exercise program promoting 225–300 minutes or more of moderate intensity physical activity per week but the majority of the studies used the same behaviour change techniques. Three studies reported clinically significant weight loss (≥ 5%) at six months post intervention. Current data indicate weight management interventions in those with ID differ from recommended practice and further studies to examine the effectiveness of multi-component weight management interventions for adults with ID and obesity are justified.

Interventions to reduce or prevent obesity in pregnant women: a systematic review.

Around 50% of women of childbearing age are either overweight [body mass index (BMI) 25-29.9 kg/m(2)] or obese (BMI ≥ 30 kg/m(2)). The antenatal period provides an opportunity to manage weight in pregnancy. This has the potential to reduce maternal and fetal complications associated with excess weight gain and obesity. To evaluate the effectiveness of dietary and lifestyle interventions in reducing or preventing obesity in pregnancy and to assess the beneficial and adverse effects of the interventions on obstetric, fetal and neonatal outcomes. Major electronic databases including MEDLINE, EMBASE, BIOSIS and Science Citation Index were searched (1950 until March 2011) to identify relevant citations. Language restrictions were not applied. Systematic reviews of the effectiveness and harm of the interventions were carried out using a methodology in line with current recommendations. Studies that evaluated any dietary, physical activity or mixed approach intervention with the potential to influence weight change in pregnancy were included. The quality of the studies was assessed using accepted contemporary standards. Results were summarised as pooled relative risks (RRs) with 95% confidence intervals (CIs) for dichotomous data. Continuous data were summarised as mean difference (MD) with standard deviation. The quality of the overall evidence synthesised for each outcome was summarised using GRADE (Grading of Recommendations Assessment, Development, and Evaluation) methodology and reported graphically as a two-dimensional chart. A total of 88 studies (40 randomised and 48 non-randomised and observational studies, involving 182,139 women) evaluated the effect of weight management interventions in pregnancy on maternal and fetal outcomes. Twenty-six studies involving 468,858 women reported the adverse effect of the interventions. Meta-analysis of 30 RCTs (4503 women) showed a reduction in weight gain in the intervention group of 0.97 kg compared with the control group (95% CI -1.60 kg to -0.34 kg; p = 0.003). Weight management interventions overall in pregnancy resulted in a significant reduction in the incidence of pre-eclampsia (RR 0.74, 95% CI 0.59 to 0.92; p = 0.008) and shoulder dystocia (RR 0.39, 95% CI 0.22 to 0.70; p = 0.02). Dietary interventions in pregnancy resulted in a significant decrease in the risk of pre-eclampsia (RR 0.67, 95% CI 0.53 to 0.85; p = 0.0009), gestational hypertension (RR 0.30, 95% CI 0.10 to 0.88; p = 0.03) and preterm birth (RR 0.68, 95% CI 0.48 to 0.96; p = 0.03) and showed a trend in reducing the incidence of gestational diabetes (RR 0.52, 95% CI 0.27 to 1.03). There were no differences in the incidence of small-for-gestational-age infants between the groups (RR 0.99, 95% CI 0.76 to 1.29). There were no significant maternal or fetal adverse effects observed for the interventions in the included trials. The overall strength of evidence for weight gain in pregnancy and birthweight was moderate for all interventions considered together. There was high-quality evidence for small-for-gestational-age infants as an outcome. The quality of evidence for all interventions on pregnancy outcomes was very low to moderate. The quality of evidence for all adverse outcomes was very low. The included studies varied in the reporting of population, intensity, type and frequency of intervention and patient complience, limiting the interpretation of the findings. There was significant heterogeneity for the beneficial effect of diet on gestational weight gain. Interventions in pregnancy to manage weight result in a significant reduction in weight gain in pregnancy (evidence quality was moderate). Dietary interventions are the most effective type of intervention in pregnancy in reducing gestational weight gain and the risks of pre-eclampsia, gestational hypertension and shoulder dystocia. There is no evidence of harm as a result of the dietary and physical activity-based interventions in pregnancy. Individual patient data meta-analysis is needed to provide robust evidence on the differential effect of intervention in various groups based on BMI, age, parity, socioeconomic status and medical conditions in pregnancy.