Guidelines for Medical Nutrition Therapy in Gestational Diabetes Mellitus: Systematic Review and Critical Appraisal

A comprehensive approach to lifestyle intervention based on a calorie-restricted diet ameliorates liver fat in overweight/obese patients with NAFLD: a multicenter randomized controlled trial in China

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a globally increasing health epidemic. Lifestyle intervention is recommended as the main therapy for NAFLD. However, the optimal approach is still unclear. This study aimed to evaluate the effects of a comprehensive approach of intensive lifestyle intervention (ILI) concerning enhanced control of calorie-restricted diet (CRD), exercise, and personalized nutrition counseling on liver steatosis and extrahepatic metabolic status in Chinese overweight and obese patients with NAFLD.

METHODS

This study was a multicenter randomized controlled trial (RCT) conducted across seven hospitals in China. It involved 226 participants with a body mass index (BMI) above 25. These participants were randomly assigned to two groups: the ILI group, which followed a low carbohydrate, high protein CRD combined with exercise and intensive counseling from a dietitian, and a control group, which adhered to a balanced CRD along with exercise and standard counseling. The main measure of the study was the change in the fat attenuation parameter (FAP) from the start of the study to week 12, analyzed within the per-protocol set. Secondary measures included changes in BMI, liver stiffness measurement (LSM), and the improvement of various metabolic indexes. Additionally, predetermined subgroup analyses of the FAP were conducted based on variables like gender, age, BMI, ethnicity, hyperlipidemia, and hypertension.

RESULTS

A total of 167 participants completed the whole study. Compared to the control group, ILI participants achieved a significant reduction in FAP (LS mean difference, 16.07 [95% CI: 8.90-23.25] dB/m) and BMI (LS mean difference, 1.46 [95% CI: 1.09-1.82] kg/m2) but not in LSM improvement (LS mean difference, 0.20 [95% CI: -0.19-0.59] kPa). The ILI also substantially improved other secondary outcomes (including ALT, AST, GGT, body fat mass, muscle mass and skeletal muscle mass, triglyceride, fasting blood glucose, fasting insulin, HbA1c, HOMA-IR, HOMA-β, blood pressure, and homocysteine). Further subgroup analyses showed that ILI, rather than control intervention, led to more significant FAP reduction, especially in patients with concurrent hypertension (p < 0.001).

CONCLUSION

In this RCT, a 12-week intensive lifestyle intervention program led to significant improvements in liver steatosis and other metabolic indicators in overweight and obese Chinese patients suffering from nonalcoholic fatty liver disease. Further research is required to confirm the long-term advantages and practicality of this approach.

TRIAL REGISTRATION

This clinical trial was registered on ClinicalTrials.gov (registration number: NCT03972631) in June 2019.

Perinatal Outcomes of Diet Therapy in Gestational Diabetes Mellitus Diagnosed before 24 Gestational Weeks

To evaluate perinatal outcomes and risk factors for large for gestational age (LGA; birth weight over 90 percentile) in gestational diabetes diagnosed before 24 gestational weeks and treated with diet therapy alone until delivery (Diet Early gestational diabetes mellitus (Diet Early GDM)), we assessed the maternal characteristics and perinatal outcomes of patients with early GDM (n = 309) and normal glucose tolerance (NGT; n = 309) at Keio University Hospital. The gestational weight gain (GWG) expected at 40 weeks was significantly lower in the Diet Early GDM group than in the NGT group. The Diet Early GDM group exhibited a significantly lower incidence of low birth weight (<2500 g) and higher Apgar score at 5 min than the NGT group. Multiple logistic regression analysis revealed that the pre-pregnancy body mass index and GWG expected at 40 weeks were significantly associated with LGA for Diet Early GDM. No differences were observed in random plasma glucose levels in the first trimester, 75 g oral glucose tolerance test values, and initial increase or subsequent decrease between the two groups. Dietary early GDM did not exhibit a worse prognosis than NGT. To prevent LGA, it might be important to control maternal body weight not only during pregnancy but also before conception.

Nutrition guidelines for preterm infants: A systematic review

BACKGROUND

There is no consensus on optimal nutrition for preterm infants, leading to substantial practice variation. We aimed to assess the quality of nutrition guidelines for preterm infants, the consistency of recommendations, and the gaps in recommendations.

METHODS

We searched databases and websites for nutrition guidelines for preterm infants before first hospital discharge, which were endorsed, prepared, or authorized by a regional, national, or international body, written in English, and published between 2012 and 2023. Two reviewers independently screened articles and extracted the recommendations. Four reviewers appraised the included guidelines using Appraisal of Guidelines, Research, and Evaluation II.

RESULTS

A total of 7051 were identified, with 27 guidelines included, 26% of which were high in quality. Most guidelines lacked stakeholder involvement and rigor of development. We found considerable variation in recommendations, many of which lacked details on certainty of evidence and strength of recommendation. Recommendations for type of feed and breastmilk fortification were consistent among high-quality guidelines, but recommendations varied for intakes of almost all nutrients and monitoring of nutrition adequacy. Different guidelines gave different certainty of evidence for the same recommendations. Most gaps in recommendations were due to very low certainty of evidence.

CONCLUSION

Future development of nutrition guidelines for preterm infants should follow the standard guideline development method and ensure the rigorous process, including stakeholders' involvement, to improve the reporting of strength of recommendation, certainty of evidence, and gaps in recommendation. Evidence is needed to support recommendations about macro and micronutrient intakes, breastmilk fortification, and markers on adequacy of intake of different nutrients.

Clinical practice guidelines on physical activity and exercise for pregnant women with gestational diabetes mellitus: A systematic review

AIM

This review aimed to appraise clinical guidelines about exercise for women with gestational diabetes mellitus and summarize consensus and inconsistent recommendations.

BACKGROUND

Exercise is an effective non-pharmacological therapeutic for gestational diabetes mellitus, but the variety of relevant clinical practice guidelines is confusing for healthcare professionals.

DESIGN

This is a systematic review of clinical practice guidelines.

DATA SOURCES

Websites of guideline development institutions, eight literature databases and organizations of obstetricians, gynaecologists, midwives, and medical sports associations were searched for guidelines published from January 2011 to October 2021.

REVIEW METHODS

Two reviewers independently extracted recommendations. Four reviewers assessed guideline quality using the AGREE II instrument independently.

RESULTS

Fifteen guidelines were included. All women with diabetes are recommended to exercise during pregnancy. The consistent recommendations were for pre-exercise screening, for 30 min per exercise session on 5 days of the week or every day after meals, exercise at moderate intensity, using aerobic and resistance exercise, and walking. The main non-consistent recommendations included warning signs for women on insulin during exercise, minimum duration per session, intensity assessment, duration and frequency of sessions for strengthening and flexibility exercise and detailed physical activity giving birth.

CONCLUSIONS

Guidelines strongly support pregnant women with diabetes to exercise regularly. Research is needed to make non-consistent recommendations clear.

Association between eating habits during adolescence and gestational diabetes: data from the Japan environment and children's study

Purpose

It is difficult to change pre-pregnancy eating habits, yet establishing healthy eating habits before pregnancy is important for preventing gestational diabetes mellitus (GDM). This study aimed to examine whether the weight-loss behavior of avoiding between-meal and midnight snacking in teenagers is associated with a reduction in the risk of subsequent GDM.

Methods

We used a dataset (jecs-an-20,180,131) from a nationwide, prospective birth cohort study, the Japan Environment and Children's Study (JECS). We included 89,227 (85.7% of the total) mother-infant pairs with live births. Participants in their second or third trimester were asked to report their weight-loss behavior during their teenage years. The prevalence of GDM was investigated. Differences in maternal characteristics were examined using chi-square tests. Crude and adjusted logistic regression models were constructed to assess the associations of various maternal characteristics with the weight-loss behavior of avoiding between-meal and midnight snacking during teenage years.

Results

A total of 2,066 (2.3%) participants had GDM. Weight-loss behavior in teenagers was associated with a decreased risk of GDM. Among participants with normal weight or overweight prior to pregnancy, the adjusted odds ratios were 0.79 (95% confidence interval, 0.70-0.89) and 0.82 (95% confidence interval, 0.69-0.98), respectively.

Conclusions

The results suggest that teenage weight-loss behaviors, such as avoiding between-meal and midnight snacking, are associated with a decreased risk of developing GDM.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01294-2.

Ketone Bodies in Diabetes Mellitus: Friend or Foe?

In glucose-deprived conditions, ketone bodies are produced by the liver mitochondria, through the catabolism of fatty acids, and are used peripherally, as an alternative energy source. Ketones are produced in the body under normal conditions, including during pregnancy and the neonatal period, when following a ketogenic diet (KD), fasting, or exercising. Additionally, ketone synthesis is also augmented under pathological conditions, including cases of diabetic ketoacidosis (DKA), alcoholism, and several metabolic disorders. Nonetheless, diet is the main regulator of total body ketone concentrations. The KDs are mimicking the fasting state, altering the default metabolism towards the use of ketones as the primary fuel source. Recently, KD has gained recognition as a medical nutrition therapy for a plethora of metabolic conditions, including obesity and diabetes mellitus (DM). The present review aims to discuss the role of ketones, KDs, ketonemia, and ketonuria in DM, presenting all the available new evidence in a comprehensive manner.

Diet Quality and Nutritional Risk Based on the FIGO Nutrition Checklist among Greek Pregnant Women: A Cross-Sectional Routine Antenatal Care Study

The International Federation of Gynecology and Obstetrics (FIGO) nutrition checklist is a tool for everyday antenatal clinical practice, easy to use by most healthcare professionals, aiming to initiate a conversation regarding gestational weight gain (GWG) and nutrition and identify women who might require further assessment. The present cross-sectional study aimed to apply the FIGO nutrition checklist to pregnant women attending routine antenatal care and identify nutritional risk factors. Pregnant women (n = 200) were recruited from the outpatient pregnancy clinics of two hospitals in Thessaloniki and completed the checklist. The FIGO-diet quality score and the FIGO-nutritional risk score (NRS) were calculated. The results revealed that 99% of the women exhibited at least one nutritional risk factor based on the checklist. The median FIGO diet quality score of the sample was 4.0 (3.0-5.0), with 95% of the participants responding negatively to at least one question, indicating the need for improving diet quality. Improved diet quality was noted in cases of hyperemesis gravidarum and among those receiving vitamin D supplements. A large percentage of the participants (36%) exhibited five or more nutritional risk factors, as indicated by a total FIGO-NRS below 5. Women with low middle-upper arm circumference, indicative of protein-energy malnutrition (20.6% of the sample), exhibited more nutritional risk factors compared with the rest. On the other hand, being in the third trimester of pregnancy was associated with lower nutritional risk and, subsequently, better diet quality.

Re-examination of the estimated average requirement for carbohydrate intake during pregnancy: Addition of placental glucose consumption

Evidence-based dietary reference intakes for nutrients in healthy individuals were last set in 2005 by the Institute of Medicine. For the first time, these recommendations included a guideline for carbohydrate intake during pregnancy. The recommended dietary allowance (RDA) was set at ≥175 g/d or 45%-65% of total energy intake. In the decades since, carbohydrate intake has been declining in some populations, and many pregnant women consume carbohydrates below the RDA. The RDA was developed to account for both maternal brain and fetal brain glucose requirements. However, the placenta also requires glucose as its dominant energy substrate and is as dependent on maternal glucose as the brain. Prompted by the availability of evidence demonstrating the rate and quantity of human placental glucose consumption, we calculated a potential new estimated average requirement (EAR) for carbohydrate intake to account for placental glucose consumption. Further, by narrative review, we have re-examined the original RDA by applying contemporary measurements of adult brain and whole-body fetal glucose consumption. We also propose, using physiologic rationale, that placental glucose consumption be included in pregnancy nutrition considerations. Calculated from human in vivo placental glucose consumption data, we suggest that 36 g/d represents an EAR for adequate glucose to support placental metabolism without supplementation by other fuels. A potential new EAR of 171 g/d accounts for maternal (100 g) and fetal (35 g) brain, and now placental glucose utilization (36 g), and with extrapolation to meet the needs of nearly all healthy pregnant women, would result in a modified RDA of 220 g/d. Lower and upper safety thresholds for carbohydrate intake remain to be determined, of importance as preexisting and gestational diabetes continue to rise globally, and nutrition therapy remains the cornerstone of treatment.

Improvement of stress adaptation and insulin resistance in women with GDM by WeChat group management during novel coronavirus pneumonia

Aim

To evaluate the improvement of glycemic control and stress adaptation in patients with GDM by mobile phone WeChat management during novel coronavirus pneumonia.

Methods

In this study, 75 women with GDM were included, of whom 35 were included in mobile WeChat group management as the GDM-M group and 40 as the GDM group.

Results

After mobile WeChat group management for 4 weeks, E and NE were lower. MDA was lower, and SOD was higher. HOMA-IR was lower. E, NE, and cortisol were related to HOMA-IR positively, MDA was positively related to HOMA-IR, and SOD was negatively related to HOMA-IR. E and cortisol were positively related to MDA but negatively related to SOD.

Conclusion

The stress adaptation disorder and insulin resistance in patients with GDM who have completed mobile WeChat group management can be improved during novel coronavirus pneumonia. Mobile WeChat management played a positive role in improving the insulin resistance of women with GDM under special circumstances, which may reduce the risk of maternal and fetal complications.

Community-based non-pharmacological interventions for pregnant women with gestational diabetes mellitus: a systematic review

BACKGROUND

Non-pharmacological interventions are the first line of Gestational diabetes mellitus (GDM) management. Community-based interventions are cheaper, more accessible, with higher patient satisfaction.

OBJECTIVES

To systematically review community-based non-pharmacological interventions and evaluate their effectiveness for GDM.

SEARCH STRATEGY

Twelve bibliographic databases and reference list of related studies from inception until January 2022.

SELECTION CRITERIA

All primary studies of community-based non-pharmacological interventions for GDM reported in English which investigated any behavioural or clinical outcome(s).

DATA COLLECTION AND ANALYSIS

Data were extracted using modified Cochrane's data extraction template. Studies were evaluated using Cochrane Collaboration's risk of bias tool. Narrative synthesis was used to summarise findings. This study is registered with PROSPERO (CRD42021257634).

MAIN RESULTS

Twenty-seven studies involving 6,242 pregnant women with GDM investigated self-management programmes, medical nutrition/diet therapy, exercise/physical activity, combined diet and exercise, calcium plus vitamin D supplementation, and continuous glucose monitoring. Self-management programmes were more effective than routine care in improving self-efficacy, two-hour postprandial blood glucose, and lifestyle behaviours but were as effective as routine care in improving infant birth weight. Self-management programmes were superior to or as effective as usual care in improving fasting blood glucose, blood glucose control, glycated haemoglobin, macrosomia, and preterm delivery. Medical nutrition/diet therapy was more effective than usual care in improving postprandial blood glucose levels. Postprandial blood glucose levels were better improved by regular supervised exercise plus daily brisk walks or a daily walking intervention than routine obstetric care or no treatment. The effects of exercise/physical activity programmes were mostly inconsistent for other outcomes. Diet and exercise were superior to diet alone in reducing maternal weight gain although there were similar outcomes for other pregnancy and foetal outcomes. Limited or conflicting evidence was found for other outcomes and interventions including calcium and vitamin D supplementation and continuous glucose monitoring intervention.

CONCLUSIONS

Community-based non-pharmacological interventions are more effective than placebo; and are more or as effective as usual care. Self-management programmes and medical nutrition/diet therapy had the most promising GDM outcomes.

FUNDING

There was no funding for this study. The study design, data collection, data analysis and interpretation, and writing of this manuscript were not influenced externally by any funder.

Effect of Exercise on the Resting Metabolic Rate and Substrate Utilization in Women with Gestational Diabetes Mellitus: Results of a Pilot Study

Regular physical activity during pregnancy has a positive effect on the mother and fetus. However, there is scarce data regarding the effect of exercise in pregnancies complicated by gestational diabetes mellitus (GDM). The aim of the present parallel, non-randomized, open-label, pilot, clinical study was to examine the effect of two exercise programs on the resting metabolic rate (RMR) and substrate utilization in pregnancies complicated by GDM, compared with usual care (advice for the performance of exercise). Forty-three pregnant women diagnosed with GDM between the 24th and 28th gestational week, volunteered to participate. Three groups were formed: Usual care (n = 17), Walking (n = 14), and Mixed Exercise (n = 12). The Usual care group was given advice on maintaining habitual daily activities without any additional exercise. The Walking group exercised regularly by walking, in addition to the habitual daily activities. Finally, the Mixed Exercise group participated in a program combining aerobics and strength exercises. Training intensity was monitored continuously using lightweight, wearable monitoring devices. The Walking and Mixed Exercise groups participated in the training programs after being diagnosed with GDM and maintained them until the last week of gestation. RMR and substrate utilization were analyzed using indirect calorimetry for all participants twice: between 27th and 28th gestational week and as close as possible before delivery. No differences were observed between groups regarding body composition, age, and medical or obstetrical parameters before or after the exercise programs. RMR was increased after the completion of the exercise interventions in both the Walking (p = 0.001) and the Mixed Exercise arms (p = 0.002). In contrast, substrate utilization remained indifferent. In conclusion, regular exercise of moderate intensity (either walking, or a combination of aerobic and strength training) increases RMR in women with GDM compared to the lack of systematic exercise. However, based on the present, pilot data, these exercise regimes do not appear to alter resting substrate utilization.

The importance of nutrition in pregnancy and lactation: lifelong consequences

Most women in the United States do not meet the recommendations for healthful nutrition and weight before and during pregnancy. Women and providers often ask what a healthy diet for a pregnant woman should look like. The message should be “eat better, not more.” This can be achieved by basing diet on a variety of nutrient-dense, whole foods, including fruits, vegetables, legumes, whole grains, healthy fats with omega-3 fatty acids that include nuts and seeds, and fish, in place of poorer quality highly processed foods. Such a diet embodies nutritional density and is less likely to be accompanied by excessive energy intake than the standard American diet consisting of increased intakes of processed foods, fatty red meat, and sweetened foods and beverages. Women who report “prudent” or “health-conscious” eating patterns before and/or during pregnancy may have fewer pregnancy complications and adverse child health outcomes. Comprehensive nutritional supplementation (multiple micronutrients plus balanced protein energy) among women with inadequate nutrition has been associated with improved birth outcomes, including decreased rates of low birthweight. A diet that severely restricts any macronutrient class should be avoided, specifically the ketogenic diet that lacks carbohydrates, the Paleo diet because of dairy restriction, and any diet characterized by excess saturated fats. User-friendly tools to facilitate a quick evaluation of dietary patterns with clear guidance on how to address dietary inadequacies and embedded support from trained healthcare providers are urgently needed.

Recent evidence has shown that although excessive gestational weight gain predicts adverse perinatal outcomes among women with normal weight, the degree of prepregnancy obesity predicts adverse perinatal outcomes to a greater degree than gestational weight gain among women with obesity. Furthermore, low body mass index and insufficient gestational weight gain are associated with poor perinatal outcomes. Observational data have shown that first-trimester gain is the strongest predictor of adverse outcomes. Interventions beginning in early pregnancy or preconception are needed to prevent downstream complications for mothers and their children. For neonates, human milk provides personalized nutrition and is associated with short- and long-term health benefits for infants and mothers. Eating a healthy diet is a way for lactating mothers to support optimal health for themselves and their infants.

Health professionals' views and experiences around the dietary and lifestyle management of gestational diabetes in New Zealand

AIM

This study aimed to investigate New Zealand health professionals' views and experiences around the dietary and lifestyle management of gestational diabetes.

METHODS

Semi-structured interviews were conducted remotely with health professionals; sessions were recorded and transcribed. Core themes were extracted using inductive thematic analysis using a framework method.

RESULTS

Twenty-seven health professionals were interviewed (13 diabetes dietitians, 8 specialist diabetes midwives, 2 community midwives, 1 antenatal clinic midwife, 1 obstetrician and 2 endocrinologists). Themes were organised into three central domains: (a) Social and cultural barriers, (b) Service provision and (c) Nutrition advice. Enabling themes included professional collaboration, innovation and creating trusting and supportive environments. Key barriers identified included accessibility, cultural barriers, overwhelmed service, fragmentation and conflicting information and nutrition resource gaps.

CONCLUSIONS

Findings highlight foremost a deficit in primary antenatal nutrition advice that may play a significant role in the fragmentation identified. Investment in community-inclusive services providing antenatal nutrition and diabetes education appears critical to overcome barriers associated with misinformation and poor outcomes. Pathways to include nutrition education from various primary care health providers should be investigated to ease the burden from specialist gestational diabetes clinicians and allow effective delegation of dietetic resources. Revision of current nutrition guidelines for the management of gestational diabetes in New Zealand is needed to facilitate consistent messaging and standards of care.

The effect of bedtime snacks on fasting blood glucose levels in gestational diabetes mellitus

AIM

To investigate the effect of different bedtime snacks (higher carbohydrate versus lower carbohydrate versus no snack) on first morning fasting blood glucose levels (BGLs) in women with diet-controlled gestational diabetes mellitus (GDM) and borderline fasting glucose levels.

METHODS

This prospective randomised crossover trial enrolled women with diet controlled GDM between 24 and 34 weeks gestation who had two or more first morning fasting BGLs between 4.7 and 5.4 mmol/L in the week prior to recruitment. The women were randomly allocated to 6 different orders of 5 days each of a standardised higher carbohydrate bedtime snack, a lower carbohydrate bedtime snack and no bedtime snack. The primary outcome was fasting capillary BGL as measured with a home glucometer, and the secondary outcome was requirement for insulin as assessed by a physician.

RESULTS

A total of 68 women with GDM were enrolled in and completed the study at a median gestation of 30.8 weeks. Compared with no bedtime snack, the higher carbohydrate snack (4.96 vs 4.87 mmol/L, mean difference: 0.09 mmol/L, 95% CI 0.05-0.13, p < 0.001) and the lower carbohydrate snack (5.01 vs 4.87 mmol/L, mean difference: 0.14 mmol/L, 95% CI 0.09-0.18, p < 0.001) were both associated with a slightly higher fasting BGL the following morning.

CONCLUSIONS

Taking a bedtime snack was associated with slightly higher fasting BGLs in women with diet-controlled GDM compared with no bedtime snack (Clinical trial registration: ACTRN12617000659303).

Clinical Practice Guidelines That Address Physical Activity and Exercise During Pregnancy: A Systematic Review

INTRODUCTION

Physical activity is recommended for healthy pregnant women. Clinical practice guidelines vary with regard to initial time, duration, or type of physical activity that is recommended, which is confusing for health care professionals and pregnant women alike. This study aimed to appraise clinical guidelines relevant to physical activity for pregnant women and summarize consensus and discrepant recommendations.

METHODS

The websites of organizations that develop guidelines including those of obstetricians, gynecologists, midwives, and medical sports associations were searched in addition to 9 literature databases for the period from January 2010 through November 2020. Guidelines were included if they were published in a journal or on a website in English or Chinese; were labeled as a recommendation guideline, position paper, practice parameter, or consensus statement; and addressed physical activity for pregnant women. Two authors independently extracted recommendations. Four reviewers independently assessed guideline quality using the AGREE II instrument.

RESULTS

Thirteen guidelines met the inclusion criteria. The guidelines developed by the World Health Organization and the National Institute for Health and Clinical Excellence were deemed to have the highest methodological quality. The recommendations were consistent with regard to recommended exercise duration, frequency, intensity, and type of physical activity. The main discrepant recommendations included best tools for conducting pre-exercise screening and assessing intensity of exertion. Guidelines also differ on optimal heart rate during exercise, when in pregnancy to initiate an exercise regimen, and duration or frequency of strengthening exercises.

DISCUSSION

Of the 13 guidelines, 2 were found to have good methodological quality. The recommendations that were consistent across the differing guidelines can support health care providers in counseling women about physical activity during pregnancy. The recommendations that are discrepant among these guidelines may contribute to confusion and a reluctance to recommend exercise during pregnancy. Research is needed to clarify discrepant recommendations.

The Perspectives of Diabetes Educators and Dietitians on Diet and Lifestyle Management for Gestational Diabetes Mellitus: A Qualitative Study

This study explores the knowledge and practice of diabetes educators and dietitians on diet and lifestyle management in women with gestational diabetes mellitus (GDM). Diabetes educators and dietitians were recruited from three maternity hospitals in Adelaide (Australia), through snowball and purposive sampling. Thirteen semistructured interviews were conducted, audio recorded, transcribed verbatim, and analysed for codes and themes. Four themes emerged: guidelines and resources, dietary intervention, management delivery, and communication. Diabetes educators and dietitians demonstrated consistent knowledge of nutritional management for GDM and uniform delivery methods. However, a lack of culturally diverse resources was highlighted, along with a lack of continuity of care across the multidisciplinary team. Barriers towards uptake of dietary intervention were reflected by diabetes educators and dietitians as women showing signs of guilt and stress and disengaging from the service. Further exploration on the knowledge and practice of diabetes educators and dietitians for GDM to best inform implementation strategies for knowledge translation of nutritional management is needed. The indication of language and cultural barriers and resources highlight an ongoing key priority area to support the care of women of ethnic minorities.

Obsessed with Healthy Eating: A Systematic Review of Observational Studies Assessing Orthorexia Nervosa in Patients with Diabetes Mellitus

Orthorexia nervosa (ON) is an unspecified feeding or eating disorder (USFED) characterized by an exaggerated, unhealthy obsession with healthy eating. Τypical eating disorders (EDs) and USFEDs are common among patients with diabetes mellitus (DM), which complicates metabolic control and disease outcomes. The present systematic review summarizes the evidence on the prevalence of ON symptomatology among patients with DM. PubMed, Web of Science, Scopus, and grey literature were searched, and relevant observational studies were screened using the Rayyan software. The quality of the studies was assessed using the appraisal tool for cross-sectional studies (AXIS) and the Newcastle–Ottawa scale (NOS). Out of 4642 studies, 6 fulfilled the predefined criteria and were included in the qualitative synthesis. Most studies relied on the ORTO-15 or its adaptations to identify ON among patients with DM. No apparent sex or age differences exist regarding the prevalence of ON symptoms. None of the studies compared the prevalence of ON in patients with type 1 and type 2 DM. Most of the research was of average to good methodological quality. In conclusion, patients with DM often exhibit ON tendencies, although research is still limited regarding the etiology or mechanistic drivers behind ON and the characteristics of patients with a dual ON–DM diagnosis.

TIMER: A Clinical Study of Energy Restriction in Women with Gestational Diabetes Mellitus

Medical nutrition therapy is an integral part of gestational diabetes mellitus (GDM) management; however, the prescription of optimal energy intake is often a difficult task due to the limited available evidence. The present pilot, feasibility, parallel, open-label and non-randomized study aimed to evaluate the effect of a very low energy diet (VLED, 1600 kcal/day), or a low energy diet (LED, 1800 kcal/day), with or without personalized exercise sessions, among women with GDM in singleton pregnancies. A total of 43 women were allocated to one of four interventions at GDM diagnosis: (1) VLED (n = 15), (2) VLED + exercise (n = 4), (3) LED (n = 16) or (4) LED + exercise (n = 8). Primary outcomes were gestational weight gain (GWG), infant birth weight, complications at delivery and a composite outcomes score. Secondary outcomes included type of delivery, prematurity, small- for-gestational-age (SGA) or large-for-gestational-age (LGA) infants, macrosomia, Apgar score, insulin use, depression, respiratory quotient (RQ), resting metabolic rate (RMR) and middle-upper arm circumference (MUAC). GWG differed between intervention groups (LED median: 12.0 kg; VLED: 5.9 kg). No differences were noted in the type of delivery, infant birth weight, composite score, prevalence of prematurity, depression, RQ, Apgar score, MUAC, or insulin use among the four groups. Regarding components of the composite score, most infants (88.4%) were appropriate-for-gestational age (AGA) and born at a gestational age of 37–42 weeks (95.3%). With respect to the mothers, 9.3% experienced complications at delivery, with the majority being allocated at the VLED + exercise arm (p < 0.03). The composite score was low (range 0–2.5) for all mother-infant pairs, indicating a “risk-free” pregnancy outcome. The results indicate that adherence to a LED or VLED induces similar maternal, infant and obstetrics outcomes.

The safety and feasibility of comprehensive nutrition care in pregnant women with gestational diabetes mellitus: A protocol for systematic review and meta-analysis

BACKGROUND

The argument on the efficacy of medical nutritional therapy and comprehensive nutritional care remains to be resolved. Therefore, we conducted this protocol of systematic review and meta-analysis to evaluate the efficacy between medical nutritional therapy and comprehensive nutritional care for patients with gestational diabetes mellitus (GDM).

METHODS

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols reporting guidelines and the recommendations of the Cochrane Collaboration to conduct this study. Reviewers will search the PubMed, Cochrane Library, Web of Science, and EMBASE online databases using the key phrases "gestational diabetes mellitus," "comprehensive nutrition care," and "medical nutritional therapy" for all cohort studies published up to May 20, 2021. There is no restriction in the dates of publication or language in the search for the current review. The studies on cohort study focusing on comparing medical nutritional therapy and comprehensive nutrition care for GDM patients will be included in our meta-analysis. The outcomes include blood glucose levels, complications, weight change, and incidence of cesarean section. Where disagreement in the collection of data occurrs, this will be resolved through discussion.

RESULTS

We hypothesized that these 2 methods would provide similar therapeutic benefits.

OSF REGISTRATION NUMBER

10.17605/OSF.IO/SC8HJ.

How fragile are Mediterranean diet interventions? A research-on-research study of randomised controlled trials

Introduction

The Mediterranean diet (MD) is a traditional regional dietary pattern and a healthy diet recommended for the primary and secondary prevention of various diseases and health conditions. Results from the higher level of primary evidence, namely randomised controlled trials (RCTs), are often used to produce dietary recommendations; however, the robustness of RCTs with MD interventions is unknown.

Methods

A systematic search was conducted and all MD RCTs with dichotomous primary outcomes were extracted from PubMed. The fragility (FI) and the reverse fragility index (RFI) were calculated for the trials with significant and non-significant comparisons, respectively.

Results

Out of 27 RCTs of parallel design, the majority failed to present a significant primary outcome, exhibiting an FI equal to 0. The median FI of the significant comparisons was 5, ranging between 1 and 39. More than half of the comparisons had an FI <5, indicating that the addition of 1–4 events to the treatment arm eliminated the statistical significance. For the comparisons with an FI=0, the RFI ranged between 1 and 29 (Median RFI: 7). When the included RCTs were stratified according to masking, the use of a composite primary endpoint, sample size, outcome category, or dietary adherence assessment method, no differences were exhibited in the FI and RFI between groups, except for the RFI among different compliance assessment methods.

Conclusions

In essence, the present study shows that even in the top tiers of evidence hierarchy, research on the MD may lack robustness, setting concerns for the formulation of nutrition recommendations.

Dietary recommendations for women with gestational diabetes mellitus: a systematic review of clinical practice guidelines

CONTEXT

Dietary advice is the cornerstone of care for women with gestational diabetes mellitus (GDM) to improve maternal and infant health.

OBJECTIVES

This study aimed to compare dietary recommendations made in clinical practice guidelines (CPGs) for the management of GDM, evaluate their evidence base, identify research gaps, and assess CPG quality. The PRISMA guidelines were used.

DATA SOURCES

Six databases were searched for CPGs, published between 2000 and 2019, that included dietary advice for the management of GDM.

DATA EXTRACTION

Two reviewers independently assessed CPG quality (using the AGREE II tool) with respect to dietary recommendations (their strength, evidence base, and research gaps).

DATA ANALYSIS

Of the 31 CPGs, 68% were assessed as low quality, mainly due to lack of editorial independence. Dietary advice was recommended as the first-line treatment by all CPGs, although the dietary recommendations themselves varied and sometimes were contradictory. Most dietary recommendations were strongly made (70%), but they were often based on very low-quality (54%), or low-quality (15%) evidence. Research gaps were identified for all diet-related recommendations.

CONCLUSION

High-quality research is needed to improve the evidence base and address the research gaps identified.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42019147848.

Nutrition Management of Gestational Diabetes Mellitus

Medical nutrition therapy (MNT) is the bedrock for the management of gestational diabetes mellitus (GDM). Several different types of dietary approaches are used globally, and there is no consensus among the various professional groups as to what constitutes an ideal approach. The conventional approach of limiting carbohydrates at the cost of increasing energy from the fat source may not be most optimal. Instead, allowing higher levels of complex, low-to-medium glycaemic index carbohydrates and adequate fibre through higher consumption of vegetables and fruits seems more beneficial. No particular diet or dietary protocol is superior to another as shown in several comparative studies. However, in each of these studies, one thing was common - the intervention arm included more intensive diet counselling and more frequent visits to the dieticians. For MNT to work, it is imperative that diet advice and nutrition counselling is provided by a dietician, which is easy to understand and use and includes healthy food options, cooking methods, and practical guidance that empower and motivate to make changes towards a healthy eating pattern. Various simple tools to achieve these objectives are available, and in the absence of qualified dieticians, they can be used to train other health care professionals to provide nutrition counselling to women with GDM. Given the impact of GDM on the future health of the mother and offspring, dietary and lifestyle behaviour changes during pregnancy in women with GDM are not only relevant for immediate pregnancy outcomes, but continued adherence is also important for future health.

Searching for Utopia, the Challenge of Standardized Medical Nutrition Therapy Prescription in Gestational Diabetes Mellitus Management: A Critical Review

Gestational diabetes mellitus (GDM) is a common pregnancy disorder and the incidence is increasing worldwide. GDM is associated with adverse maternal outcomes which may be reduced with proper management. Lifestyle modification in the form of medical nutrition therapy and physical activity, as well as self-monitoring of blood glucose levels, is the cornerstone of GDM management. Inevitably, the search for the "ultimate" diet prescription has been ongoing. Identifying the amount and type of carbohydrate to maintain blood glucose levels below targets while balancing the nutritional requirements of pregnancy and achieving gestational weight gain within recommendations is challenging. Recent developments in the area of the gut microbiota and its impact on glycemic response add another layer of complexity to the success of medical nutrition therapy. This review critically explores the challenges to dietary prescription for GDM and why utopia may never be found.

Methodological quality of clinical practice guidelines for nutrition and weight gain during pregnancy: a systematic review

CONTEXT

Ensuring a healthy pregnancy and achieving optimal gestational weight gain (GWG) are important for maternal and child health. Nevertheless, the nutritional advice provided during pregnancy is often conflicting, suggesting limited adherence to clinical practice guidelines (CPGs).

OBJECTIVE

The aim of this review was to identify all CPGs on maternal nutrition and GWG and to critically appraise their methodological quality.

DATA SOURCES

The MEDLINE/PubMed, Cochrane, Guidelines International Network, and BMJ Best Practice databases, along with gray literature, were searched from inception until February 2019 for CPGs and consensus, position, and practice papers.

STUDY SELECTION

Clinical practice guidelines published in English and containing advice on maternal nutrition or GWG were eligible.

DATA EXTRACTION

Two authors independently extracted data on items pertaining to maternal nutrition or GWG, and CPGs were appraised using the AGREE II instrument.

RESULTS

Twenty-two CPGs were included. All scored adequately in the "scope" domain, but most were considered inadequate with regard to stakeholder involvement, rigor of development, applicability, and editorial independence. Many CPGs lacked patient or dietician involvement, and more than half did not disclose funding sources or conflicts of interest. Guidance on GWG was based mostly on Institute of Medicine thresholds, while nutrition recommendations appeared scattered and heterogeneous.

CONCLUSION

Despite the importance of maternal nutrition and the plethora of advising bodies publishing relevant guidance, there is room for substantial improvement in terms of development standards and content of nutritional recommendations.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42019120898.

Impact of Intensive Lifestyle Treatment (Diet Plus Exercise) on Endothelial and Vascular Function, Arterial Stiffness and Blood Pressure in Stage 1 Hypertension: Results of the HINTreat Randomized Controlled Trial

Lifestyle modification is an important component of essential hypertension (EH) therapy. The aim of the Hypertension Intensive Nutrition Treatment (HINTreat) parallel, randomized controlled trial was to examine the effect of a 6-month intensive lifestyle treatment (ILT) (diet plus exercise with monthly visits) compared to the usual care. A total of 76 adults with stage 1 EH were randomized (38 in each group). Dietary analysis, anthropometry, physical activity, biochemical and urine profile, blood pressure (BP), asymmetric dimethylarginine (ADMA), central hemodynamics, β-stiffness index and carotid intima media-thickness were evaluated. The dietary inflammatory index (DII) was calculated for each participant from the intake of 29 nutrients/food components. At the end of the trial, participants in the ILT group reduced their 24h urinary Na excretion (p ≤ 0.001), daytime systolic BP (p ≤ 0.048) and mean carotid β-stiffness index (p ≤ 0.005) and ameliorated their lipidemic profile compared to the standard care. Univariate analysis for the total sample showed a strong association between DII and ADMA levels (β = 0.089, p ≤ 0.01). ILT is effective in improving the inflammatory components of the diet and selected cardiometabolic parameters, including arterial stiffness.

The Role of Dietary Carbohydrates in Gestational Diabetes

Gestational diabetes (GDM) is hyperglycemia that is recognized for the first time during pregnancy. GDM is associated with a wide range of short- and long-term adverse health consequences for both mother and offspring. It is a complex disease with a multifactorial etiology, with disturbances in glucose, lipid, inflammation and gut microbiota. Consequently, its management is complex, requiring patients to self-manage their diet, lifestyle and self-care behaviors in combination with use of insulin. In addition to nutritional recommendations for all pregnant women, special attention to dietary carbohydrate (CHO) amount and type on glucose levels is especially important in GDM. Dietary CHO are diverse, ranging from simple sugars to longer-chain oligo- and poly- saccharides which have diverse effects on blood glucose, microbial fermentation and bowel function. Studies have established that dietary CHO amount and type can impact maternal glucose and nutritional recommendations advise women with GDM to limit total intake or choose complex and low glycemic CHO. However, robust maternal and infant benefits are not consistently shown. Novel approaches which help women with GDM adhere to dietary recommendations such as diabetes-specific meal replacements (which provide a defined and complete nutritional composition with slowly-digested CHO) and continuous glucose monitors (which provide unlimited monitoring of maternal glycemic fluctuations) have shown benefits on both maternal and neonatal outcomes. Continued research is needed to understand and develop tools to facilitate patient adherence to treatment goals, individualize interventions and improve outcomes.

Effects of Nutritional Strategies on Glucose Homeostasis in Gestational Diabetes Mellitus: A Systematic Review and Network Meta-Analysis

BACKGROUND

Gestational diabetes mellitus (GDM) is one of the most common complications of pregnancy, and nutritional therapy is the basis of GDM treatment. However, the effects of different forms of nutritional supplementation on improving gestational diabetes are uncertain.

OBJECTIVE

We conducted a network meta-analysis to evaluate the effects of supplementation with different nutrients on glucose metabolism in women with GDM.

METHODS

We conducted a literature search using PubMed, EMBASE, and the Cochrane Library to identify randomized controlled trials (RCTs) comparing the differences between different nutritional strategies in women with GDM. The Cochrane tool was used to assess the risk of bias. Pairwise meta-analysis and network meta-analysis were used to compare and rank the effects of nutritional strategies for the improvement of fasting plasma glucose (FPG), serum insulin, and homeostasis model assessment-insulin resistance (HOMA-IR).

RESULTS

We included thirteen RCTs with a total of 754 participants. Compared with placebo, omega-3, magnesium, vitamin D, zinc, and probiotics were more beneficial for improving FPG, serum insulin, and HOMA-IR. Network analysis showed that vitamin D supplementation was superior to omega-3 (-3.64 mg/dL, 95% CI: -5.77 to -1.51), zinc (-5.71 mg/dL, 95% CI: -10.19 to -1.23), probiotics (-6.76 mg/dL, 95% CI: -10.02 to -3.50), and placebo (-12.13 mg/dL, 95% CI: -14.55 to -9.70) for improving FPG. Magnesium supplementation was more beneficial for decreasing serum insulin compared with probiotics (-5.10 μIU/mL, 95% CI: -9.32 to -0.88) and placebo (-7.80 μIU/mL, 95% CI: -9.32 to -0.88) and placebo (-7.80 .

CONCLUSION

Vitamin D supplementation significantly reduced FPG and regulated HOMA-IR. Magnesium supplementation was superior in decreasing serum insulin than supplementation with other nutrients. Nutrient supplementation seemed to have an effect on glucose homeostasis maintenance in patients with GDM and may be considered an adjunctive therapy.