Dietary management of gestational diabetes: A review.

Gestational diabetes mellitus (GDM) is a common condition in pregnant women that can affect the health of both the mother and the fetus. A healthy diet reduces the risk of GDM, while on the contrary, an unhealthy diet can increase the risk of developing GDM. Dietary interventions remain an important way to control GDM at this time. However, real-life diets are complex and varied, and the effect of these diets on gestational diabetes is unknown. This article summarizes research related to dietary control of GDM. Hopefully, this will help with dietary interventions for people with GDM.

A framework to classify gestational diabetes diagnosed by routine antenatal 75g glucose tolerance testing.

OBJECTIVE: To create an objective framework to classify gestational diabetes mellitus diagnosed by routine antenatal 75 g diabetes testing results to provide an alternative to current treatment-based classification. METHODS: A framework was created to classify gestational diabetes according to the severity of glycemic abnormalities after routine antenatal 75 g GTT (classes 1 through 4, determined by fasting and post-test glycemic abnormalities). A retrospective cohort chart review was used to correlate clinically how often diet therapy alone maintained glycemic targets throughout pregnancy in each class. Chi-square analysis was used to assess inter-class differences in the success of diet therapy alone maintaining glycemic targets throughout pregnancy. RESULTS: Seventy-four of 228 (33%), 35/228 (15%), 76/228 (33%), and 43/228 (19%) of the study population were classified as Class 1, 2, 3, or 4, respectively. Of eighty-nine patients who maintained glycemic targets throughout pregnancy with diet alone 51/89 (57%) were Class 1, 20/89 (22.5%) were Class 2, 11/89 (12.5%) were Class 3, and 7/89 (8%) were Class 4. Chi-square analysis showed statistically significant inter-class differences in the likelihood of diet therapy alone maintaining glycemic targets throughout pregnancy. CONCLUSION: In this framework classifying gestational diabetes according to the severity of glycemic abnormalities after routine antenatal 75 g GTT (an objective proxy for disease severity), the higher the assigned class, the less likely that diet therapy alone maintained glycemic targets throughout pregnancy (a clinical proxy for disease severity).

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.

Introduction of the Mediterranean diet in pregnancy and the incidence of gestational diabetes mellitus: A systematic review of randomised controlled trials and meta-analysis.

OBJECTIVES: To determine if introducing the Mediterranean diet in pregnancy reduces the incidence of gestational diabetes. STUDY DESIGN: Systematic review and meta-analysis of randomised controlled trials (RCTs). A literature search was conducted using the following databases: MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and CINAHL with no language or date restrictions. Studies were deemed eligible if the population was pregnant women, the intervention was the Mediterranean diet, and the outcome was gestational diabetes. Quality assessment was carried out using the Cochrane risk of bias tool. A random effects model using Revman software was used to pool results, generating a summary risk ratio with 95 % confidence intervals (95 %CI). RESULTS AND CONCLUSIONS: The search identified three eligible studies. Across the trials, 2348 women were included. Two of the three trials defined the intervention as the Mediterranean diet supplemented with extra virgin olive oil (EVOO) and pistachios, with the control group being Mediterranean diet alone. Meta-analysis of these trials found a significant reduction in the incidence of gestational diabetes in the intervention group compared to the control group (risk ratio=0.71, 95% confidence interval=(0.57, 0.88)). In addition, this was consistent with the results of the remaining eligible trial which defined the intervention as Mediterranean diet and the control as a standard UK diet (risk ratio = 0.71, 95% confidence interval = (0.55, 0.90)). At present evidence is scarce regarding whether adopting a Mediterranean diet reduces the risk of gestational diabetes. A large multi-centre randomised controlled trial is needed to definitively determine the impact of the Mediterranean diet in pregnancy on the incidence of gestational diabetes.

Selenium Supplementation and Gestational Diabetes: A Randomised Controlled Trial.

OBJECTIVE: To assess the effects of selenium supplementation on blood glucose levels in women with gestational diabetes mellitus (GDM). STUDY DESIGN: Randomised controlled trial. Place and Duration of the Study: Department of Internal Medicine, Istanbul Medipol University, Faculty of Medicine, Istanbul, Turkiye, from February to July 2023. METHODOLOGY: In the first phase of this study, the selenium levels of the pregnant women who routinely had an oral glucose tolerance test were measured, and in the second phase of the study, the pregnant women diagnosed with GDM were randomly divided into two groups that received 4-week interventions: Diet alone and diet plus selenium supplementation (200 µg/day). RESULTS: Selenium level in pregnant women with GDM was significantly lower than in healthy pregnant women, and a selenium level less than 80 ng/ml predicted GDM diagnosis with a sensitivity of 58.59% and a specificity of 67.11%. Pregnant women with low selenium (<80 ng/ml) had a 2.709-fold higher risk for GDM compared to those with higher values. Fasting blood glucose levels decreased significantly in both groups after the respective interventions, but the decrease was greater in selenium recipients. Furthermore, fasting, 1st and 2nd hour blood glucose levels were lower in selenium recipients compared to those who only received diet. CONCLUSION: Selenium level in pregnant women with GDM was low compared to healthy pregnant women. Selenium supplementation had a beneficial impact (compared to diet only) on blood glucose levels in pregnant women with GDM. KEY WORDS: Pregnancy, Pregnancy outcome, Diabetes, Gestational, Dietary supplements, Selenium.

Probiotic intervention improves metabolic outcomes in gestational diabetes mellitus: A meta-analysis of randomized controlled trials.

AIMS: To conduct a randomized controlled trial meta-analysis and provide concise and specific recommendations for clinical practice optimization of gestational diabetes for probiotics. METHODS: Up until May 2023, we conducted a thorough, systematic search of PubMed, Cochrane Central Controlled Trials, and Embase. Stata software was used to merge the resulting data from the original studies. Cochran's Q and the I2 statistics were used to evaluate and quantify heterogeneity. The GRADE method was used to evaluate the overall quality of the evidence. Sources of heterogeneity were analyzed through a leave-one-out meta-analysis, a Galbraith plot, and a subgroup analysis. RESULTS: A meta-analysis of 11 randomized controlled trials with a total of 713 participants was finally conducted. Our findings indicated the administration of probiotics at a median dosage of 6 × 109 CFU/day led to a substantial improvement in fasting glucose levels (MD: -4.16 mg/dL [95% CI: -6.78, -1.54]; P < 0.001), fasting insulin levels (MD: -3.33 µIU/ml [95% CI: -4.92, -1.74]; P < 0.001), homeostatic model assessment for insulin resistance (HOMA-IR) (MD: -0.71 [95% CI: -0.97, -0.45]; P < 0.001), and quantitative insulin sensitivity check index (QUICKI) (MD: 0.01 [95% CI: 0.01, 0.02]; P < 0.001). Subgroup analysis indicated that probiotic intervention exerted a more significant reduction in fasting blood glucose in patients with higher baseline BMI and glucose levels, and reduced fasting insulin more markedly in those with elevated baseline insulin. According to the GRADE assessment, the quality of evidence for fasting blood glucose and QUICKI was rated as "high", while the quality for fasting insulin and HOMA-IR was rated as "moderate". CONCLUSIONS: Probiotic intervention has been shown to significantly decrease levels of fasting blood glucose, fasting insulin, and HOMA-IR, while elevating QUICKI levels in patients with GDM, underscoring the potential utility of probiotics in the adjunctive management of GDM.

Gestational Diabetes Mellitus: What Can Medical Nutrition Therapy Do?

Gestational diabetes mellitus (GDM) is one of the common complications during pregnancy. Numerous studies have shown that GDM is associated with a series of adverse effects on both mothers and offspring. Due to the particularity of pregnancy, medical nutrition treatment is considered to be the first choice for the treatment of GDM. This contribution reviews the research progress of medical nutrition treatment in GDM, summarizes the international recommendations on the intake of various nutrients and the influence of nutrients on the prevalence of GDM, and the improvement effect of nutritional intervention on it, in order to provide references for research in related fields of GDM and the targeted development of enteral nutrition.

Study on the Effects of Individualized Nutritional Intervention on Pregnancy Outcome and Neonatal Immune Function in Patients with Gestational Diabetes Mellitus.

OBJECTIVE: To study the effects of individualized nutritional intervention on pregnancy outcome and neonatal immune function in patients with gestational diabetes mellitus (GDM). METHODS: A retrospective analysis was conducted on 100 GDM patients from the obstetrics and gynecology department of our institute between February 2019 and February 2020. The patients were allocated into the control group given regular intervention and the experimental group given individualized nutritional intervention according to different intervention measures, with 50 cases in each group. The comparison was carried out for patients in the two groups with regard to their modality of delivery, neonatal health, their plasma glucose in fasting state, 2 h after eating, and before bedtime; glycohemoglobin at 8 months of pregnancy, at 9 months of pregnancy, during labor, and 1 month after delivery; their complications; and neonatal CD3+, CD4+, and CD8+ levels. RESULTS: The experimental group outperformed the control group in terms of the spontaneous delivery rate, the number of healthy neonates, and neonatal CD3+, CD4+, and CD8+ levels (P < 0.05). The plasma glucose in fasting state, 2 h after eating, and before bedtime; the glycohemoglobin at 8 months of pregnancy, at 9 months of pregnancy, during labor, and 1 month after delivery; and the incidence of complications of the experimental group were significantly lower than those of the control group (P < 0.05). CONCLUSION: Individualized nutritional intervention increases the rate of spontaneous delivery in GDM patients, enhances neonatal immune function, stabilizes plasma glucose, and reduces complications.

Does a high dietary intake of resistant starch affect glycaemic control and alter the gut microbiome in women with gestational diabetes? A randomised control trial protocol.

BACKGROUND: Gestational Diabetes Mellitus (GDM) is prevalent with lasting health implications for the mother and offspring. Medical nutrition therapy is the foundation of GDM management yet achieving optimal glycaemic control often requires treatment with medications, like insulin. New dietary strategies to improve GDM management and outcomes are required. Gut dysbiosis is a feature of GDM pregnancies, therefore, dietary manipulation of the gut microbiota may offer a new avenue for management. Resistant starch is a fermentable dietary fibre known to alter the gut microbiota and enhance production of short-chain fatty acids. Evidence suggests that short-chain fatty acids improve glycaemia via multiple mechanisms, however, this has not been evaluated in GDM. METHODS: An open-label, parallel-group design study will investigate whether a high dietary resistant starch intake or resistant starch supplement improves glycaemic control and changes the gut microbiome compared with standard dietary advice in women with newly diagnosed GDM. Ninety women will be randomised to one of three groups - standard dietary treatment for GDM (Control), a high resistant starch diet or a high resistant starch diet plus a 16 g resistant starch supplement. Measurements taken at Baseline (24 to 30-weeks' gestation), Day 10 and Day 56 (approximately 36 weeks' gestation) will include fasting plasma glucose levels, microbial composition and short-chain fatty acid concentrations in stool, 3-day dietary intake records and bowel symptoms questionnaires. One-week post-natal data collection will include microbial composition and short-chain fatty acid concentrations of maternal and neonatal stools, microbial composition of breastmilk, birthweight, maternal and neonatal outcomes. Mixed model analysis of variance will assess change in glycaemia and permutation-based multivariate analysis of variance will assess changes in microbial composition within and between intervention groups. Distance-based linear modelling will identify correlation between change in stool microbiota, short-chain fatty acids and measures of glycaemia. DISCUSSION: To improve outcomes for GDM dyads, evaluation of a high dietary intake of resistant starch to improve glycaemia through the gut microbiome needs to be established. This will expand the dietary interventions available to manage GDM without medication. TRIAL REGISTRATION: Australian New Zealand Clinical Trial Registry, ACTRN12620000968976p . Registered 28 September 2020.

Comparative effectiveness of adjunct non-pharmacological interventions on maternal and neonatal outcomes in gestational diabetes mellitus patients: A systematic review and network meta-analysis protocol of randomized controlled trials.

BACKGROUND: Gestational diabetes mellitus (GDM) in pregnancy leads to a range of perinatal complications. Although several randomized controlled trials (RCT) have tested the effect of non-pharmacological standard GDM care adjuncts on these outcomes, there is no agglomerated statistical evidence on how their occurrence risk varies across interventions and with placebo. Therefore, a systematic review and network meta-analysis (NMA) protocol is proposed here to address this evidence gap. MATERIALS AND METHODS: A search for above RCTs published in the English language will transpire in PubMed, Embase, and Scopus databases irrespective of date and geographic boundary. The RCTs must test nutritional supplementation, digital intervention, structured exercise program, educational program, counseling service, or a combination of these prenatally in GDM patients. These should report ≥1 of the following outcomes- cesarean section, pre-eclampsia, polyhydramnios, preterm birth, macrosomia, prolonged labor, gestational hypertension, premature rupture of membranes, congenital anomaly, Apgar scores, birth weight, birth length, gestational age at birth, neonatal hypoglycemia, neonatal hyperbilirubinemia, and neonatal Corpulence Index. The risk of bias assessment of the recruited trials will transpire using the Revised Cochrane risk-of-bias tool. Determination of the comparative effectiveness between interventions will occur by the frequentist method NMA for respective outcomes. The categorical and continuous outcomes effect size will get calculated in risk ratio and weighted or standardized mean difference, respectively. For each NMA model, network maps and league tables will show the connections between interventions and effect sizes with their 95% confidence intervals for each intervention pair compared, respectively. The publication bias assessment will occur using comparison-adjusted funnel plots. Best intervention prediction for NMA models with statistically significant intervention effect will happen by determining the surface under the cumulative ranking curve values. Statistical analysis will ensue using Stata software (v16). The statistical significance estimation will happen at p<0.05 and 95% confidence interval. TRIAL REGISTRATION: PROSPERO registration no: CRD42021271199; https://clinicaltrials.gov/.

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).

New Zealand women's experiences of managing gestational diabetes through diet: a qualitative study.

BACKGROUND: For women with gestational diabetes mellitus (GDM) poor dietary choices can have deleterious consequences for both themselves and their baby. Diet is a well-recognised primary strategy for the management of GDM. Women who develop GDM may receive dietary recommendations from a range of sources that may be inconsistent and are often faced with needing to make several dietary adaptations in a short period of time to achieve glycaemic control. The aim of this study was to explore how women diagnosed with GDM perceive dietary recommendations and how this information influences their dietary decisions during pregnancy and beyond. METHODS: Women diagnosed with GDM before 30 weeks' gestation were purposively recruited from two GDM clinics in Auckland, New Zealand. Data were generated using semi-structured interviews and thematic analysed to identify themes describing women's perceptions and experiences of dietary recommendations for the management of GDM. RESULTS: Eighteen women from a diverse range of sociodemographic backgrounds participated in the study. Three interconnected themes described women's perceptions of dietary recommendations and experiences in managing their GDM through diet: managing GDM is a balancing act; using the numbers as evidence, and the GDM timeframe. The primary objective of dietary advice was perceived to be to control blood glucose levels and this was central to each theme. Women faced a number of challenges in adhering to dietary recommendations. Their relationships with healthcare professionals played a significant role in their perception of advice and motivation to adhere to recommendations. Many women perceived the need to follow dietary recommendations to be temporary, with few planning to continue dietary adaptations long-term. CONCLUSIONS: The value of empathetic, individually tailored advice was highlighted in this study. A greater emphasis on establishing healthy dietary habits not just during pregnancy but for the long-term health of both mother and baby is needed.

An Update of Medical Nutrition Therapy in Gestational Diabetes Mellitus.

Gestational diabetes mellitus (GDM) is a serious and frequent pregnancy complication that can lead to short and long-term risks for both mother and fetus. Different health organizations proposed different algorithms for the screening, diagnosis, and management of GDM. Medical Nutrition Therapy (MNT), together with physical exercise and frequent self-monitoring, represents the milestone for GDM treatment in order to reduce maternal and fetal complications. The pregnant woman should benefit from her family support and make changes in their lifestyles, changes that, in the end, will be beneficial for the whole family. The aim of this manuscript is to review the literature about the Medical Nutrition Therapy in GDM and its crucial role in GDM management.

Continuous Glucose Monitoring in Women with Normal OGTT in Pregnancy.

Continuous glucose monitoring (CGM) might be an effective tool to improve glycemic control in gestational diabetes mellitus (GDM). Few data are available about its utilization as a diagnostic tool to find potential alterations of glycemia in subjects with normal oral glucose tolerance test (OGTT). In this preliminary prospective real-life observational study, we aimed to analyze the glycemic pattern in normal and gestational diabetes mellitus (GDM) women by continuous glucose monitoring (CGM) in order to detect potential differences between the two groups and glycemic alterations despite a normal OGTT. After the screening for GDM, subjects were connected to a CGM system for seven consecutive days. The areas under the curve of the first 60 minutes after each meal and 60 minutes before breakfast were analyzed. Women with normal OGTT that during CGM showed impaired glycemic values (more than 95 fasting or more than 140 one hour after meals or more than 120 two hours after meals) performed one week of self-monitoring of blood glucose (SMBG). After OGTT, 53 women considered normal and 46 affected by GDM were included. CGM parameters did not show any differences between the two groups with impaired glycemic excursions found in both groups. After CGM period, 33 women with normal OGTT showed abnormal glycemic patterns. These 33 women then performed one week of SMBG. After evaluation of one week of SMBG, 21 required diet therapy and 12 required insulin treatment and were followed until the delivery. An increase in gestational weight gain was observed in normal women with normal OGTT but this was not significant. No significant data were found regarding neonatal outcomes in the two groups of women. In conclusion, CGM use in pregnancy might help to detect glycemic fluctuations in women with normal OGTT, improving their treatment and outcomes.

Early gut dysbiosis could be an indicator of unsuccessful diet control in gestational diabetes mellitus.

Highlights At the time of gestational diabetes mellitus (GDM) diagnosis, gut dysbiosis was severer in mothers who ended up with diet control failure than those who ended up with successful diet control. This finding was noticed even when the glycemic profile at the time of GDM diagnosis was similar between these two groups. Interestingly, gut dysbiosis in GDM mothers with diet control failure was shown associated with gut dysbiosis in their newborns.

A Glimpse at the Size of the Fetal Liver-Is It Connected with the Evolution of Gestational Diabetes?

Gestational diabetes mellitus (GDM) is defined as an impairment of glucose tolerance, manifested by hyperglycemia, which occurs at any stage of pregnancy. GDM is more common in the third trimester of pregnancy and usually disappears after birth. It was hypothesized that the glycemic status of the mother can modulate liver development and growth early during the pregnancy. The simplest modality to monitor the evolution of GDM employs noninvasive techniques. In this category, routinely obstetrical ultrasound (OUS) examinations (simple or 2D/3D) can be employed for specific fetal measurements, such as fetal liver length (FLL) or volume (FLV). FLL and FLV may emerge as possible predictors of GDM as they positively relate to the maternal glycated hemoglobin (HbA1c) levels and to the results of the oral glucose tolerance test. The aim of this review is to offer insight into the relationship between GDM and fetal nutritional status. Risk factors for GDM and the short- and long-term outcomes of GDM pregnancies are also discussed, as well as the significance of different dietary patterns. Moreover, the review aims to fill one gap in the literature, investigating whether fetal liver growth can be used as a predictor of GDM evolution. To conclude, although studies pointed out a connection between fetal indices and GDM as useful tools in the early detection of GDM (before 23 weeks of gestation), additional research is needed to properly manage GDM and offspring health.

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.

Effect of an individualised nutritional intervention on gestational diabetes mellitus prevention in a high-risk population screened by a prediction model: study protocol for a multicentre randomised controlled trial.

BACKGROUND: The ability of a preventive nutritional intervention to reduce the morbidity of gestational diabetes mellitus (GDM) remains controversial. We aim to assess whether GDM can be prevented by an individualised nutritional intervention in pregnant women who are at high risk for the disease based on a prediction model. METHODS/DESIGN: A multicentre randomised controlled trial was designed to assess the efficacy of an individualised nutritional intervention for the prevention of GDM in a high-risk population screened by a novel prediction model in the first trimester. Pregnant women evaluated to be at high risk for GDM by the prediction model at less than 14 gestational weeks will be included. Women with pre-existing chronic diseases, including pregestational diabetes, or who are currently prescribed medicines that affect glucose values will be excluded. Allocation to intervention/control at a ratio of 1:1 will be conducted by a computerized randomisation system. The intervention group will complete 3-day food records and receive 3 individualised nutritional consultations with professional dieticians before the oral glucose tolerance test. The primary intention of the intervention is to promote a long-term healthy dietary pattern and prevent excessive gestational weight gain throughout pregnancy. The control group will complete 3-day food records at designated gestational weeks and receive standard antenatal care according to local health care provisions. The primary outcome is the incidence of GDM according to the criteria of the International Association of Diabetes and Pregnancy Study Group (IADPSG). A sample of 464 participants will provide 80% power to detect a 30% reduction in GDM incidence (α = 0.05 two tailed, 10% dropout). A total of 500 participants will be recruited. DISCUSSION: To date, this is the first randomised controlled trial aimed to evaluate the protective effect of an individualised nutritional intervention against GDM based on a logistic regression prediction model. Eligibility is not limited to obese women or singleton pregnancies, as in previous studies. This pragmatic trial is expected to provide valuable information on early screening and effective GDM prevention methods. TRIAL REGISTRATION NUMBER: ChiCTR, ChiCTR1900026963 . Registered 27 October 2019.