Indices of dietary fat quality during midpregnancy is associated with gestational diabetes

Advances in free fatty acid profiles in gestational diabetes mellitus

The morbidity of gestational diabetes mellitus (GDM) is increasing and is associated with adverse perinatal outcomes and long-term maternal and infant health. The exact mechanism underlying changes in plasma free fatty acid (FFA) profiles in patients with GDM is unknown. However, it is believed that changes in diet and lipid metabolism may play a role. Fatty acids contain many specific FFAs, and the type of FFA has different impacts on physiological processes; hence, determining changes in FFAs in individual plasma is essential. Alterations in FFA concentration or profile may facilitate insulin resistance. Additionally, some FFAs show potential to predict GDM in early pregnancy and are strongly associated with the growth and development of the fetus and occurrence of macrosomia. Here, we aimed to review changes in FFAs in women with GDM and discuss the relationship of FFAs with GDM incidence and adverse outcomes.

The interaction between MALAT1 and TUG1 with dietary fatty acid quality indices on visceral adiposity index and body adiposity index

We aimed to investigate the interaction between the transcript levels of taurine-upregulated gene 1 (TUG1) and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and the Cholesterol-Saturated Fat Index (CSI) in relation to the visceral adiposity index (VAI) and body adiposity index (BAI). This cross-sectional study involved 346 women classified as obese and overweight, aged between 18 and 48 years. Dietary intake and the quality of dietary fat were assessed using a validated and reliable 147-item semi-quantitative food frequency questionnaire, with the Cholesterol-Saturated Fat Index (CSI) used as an indicator. Transcription levels of MALAT1 and TUG1 were evaluated through real-time polymerase chain reaction following the criteria outlined in the Minimum Information for Publication of Quantitative standards. Serum profiles were measured using standard protocols. We observed a positive association between transcription level of MALAT1 and VAI in both crude (β = 3.646, 95% CI 1.950-5.341, p < 0.001) and adjusted (β = 8.338, 95% CI 6.110-10.566, p < 0.001) models. Furthermore, after adjusting for confounders, a significant positive interaction was noted between MALAT1 expression and CSI on BAI (β: 0.130, 95% CI 0.019, 0.240, p = 0.022), with a marginal positive interaction observed on VAI (β: 0.718, 95% CI - 0.028, 1.463, p = 0.059). It seems that there may be a positive interaction between MALAT1 transcription level and CSI on VAI and BAI among overweight and obese women. However, no associations were seen between TUG1 mRNA level and the above-mentioned outcomes. Further functional studies are still required to elucidate this concept.

[Maternal factors associated with habitual consumption of ultra-processed foods during pregnancy]

The scope of the study was to investigate the relationship between maternal sociodemographic, obstetric and lifestyle characteristics and the habitual consumption of ultra-processed foods. It included a cross-sectional study of n = 784 pregnant women attended by the Unified Health System. Diet was estimated using two 24-hour recall surveys, using the multiple-pass method. Ultra-processed foods were classified using the UN NOVA food classification and their habitual consumption was expressed as the contribution to the total energy percentage. Adjusted linear regression models were used to investigate the relationship between maternal characteristics and the percentage of energy (%E) derived from ultra-processed foods. The %E of ultra-processed foods in the diet was 32.1%. Maternal age (-0.45[-0.62; -0.29] p < 0.001), economic bracket D+E in relation to A+B (-2.95[-5.59; -0.32] p = 0.03) and energy underreporting (-6.95[-8.86; -5.04] p < 0.001) were inversely associated with the %E of ultra-processed foods, whereas the pre-pregnancy Body Mass Index (BMI) (0.41[0.22; 0.60] p < 0.001) was directly associated. This would suggest that maternal age, economic status, energy underreporting and pre-gestational anthropometric status are associated with the consumption of ultra-processed foods during pregnancy.

Maternal dietary components in the development of gestational diabetes mellitus: a systematic review of observational studies to timely promotion of health

BACKGROUND

There is ample evidence that considers diet as an important factor in the prevention of gestational diabetes mellitus (GDM). The aim of this review is to synthesise the existing evidence on the relationship between GDM and maternal dietary components.

METHODS

We performed a systematic bibliographic search in Medline, Latin American and Caribbean Health Sciences Literature (Lilacs) and the Latin American Nutrition Archive (ALAN) of regional and local literature, limiting the searches to observational studies published between 2016 and 2022. Search terms related to nutrients, foods, dietary patterns and the relationship to GDM risk were used. The review included 44 articles, 12 of which were from America. The articles considered different topics about maternal dietary components as follows: 14 are about nutrient intake, 8 about food intake, 4 combined nutrient and food analysis and 18 about dietary patterns.

RESULTS

Iron, processed meat and a low carbohydrate diet were positively associated with GDM. Antioxidant nutrients, folic acid, fruits, vegetables, legumes and eggs were negatively associated with GDM. Generally, western dietary patterns increase GDM risk, and prudent dietary patterns or plant-based diets decrease the risk.

CONCLUSIONS

Diet is considered one of the causes of GDM. However, there is no homogeneity in how people eat nor in how researchers assess diet in different contextual conditions of the world.

Interaction between caveolin-1 polymorphism and dietary fat quality indexes on visceral adiposity index (VAI) and body adiposity index (BAI) among overweight and obese women: a cross-sectional study

BACKGROUND AND AIMS

Caveolin-1 (CAV-1) in adipocyte tissue and other body parts possesses numerous biological functions. In the present study, we sought to investigate the interaction between CAV-1 polymorphism and dietary fat quality indexes on visceral adiposity index (VAI) and body adiposity index (BAI) among overweight and obese women.

METHODS

This study was conducted on 386 women aged 18-48 years old. Biochemical measurements were assessed by standard protocols. We used a food frequency questionnaire (FFQ) to calculate the dietary intake and the indexes of dietary fat quality intake. Anthropometric values and body composition were measured by standard methods. Finally, the CAV-1 genotype was measured using the PCR-RFLP method.

RESULTS

We found marginally significant differences between AA and GG genotypes of waist-to-hip ratio (WHR) (P = 0.06) and BAI (P = 0.06) of participants after adjusting for potential confounders. For dietary intakes, after adjusting with the energy intake, mean differences in biotin (P = 0.04) and total fiber (P = 0.06) were significant and marginally significant, respectively. The interaction between two risk alleles (AA) with omega-6 to omega-3 ratio (W6/W3) on BAI, after adjustment for potential confounders (age, physical activity, energy intake, education), was marginally positive (β = 14.08, 95% CI = - 18.65, 46.81, P = 0.07). In comparison to the reference group (GG), there was a positive interaction between the two risk alleles (AA) with W6/W3 ratio on VAI (β = 2.81, 95% CI = 1.20, 8.84, P = 0.06) in the adjusted model.

CONCLUSIONS

We found that there might be an interaction between CAV-1 genotypes with dietary quality fat indexes on VAI and BAI among overweight and obese women.

Dietary fat quantity and quality in early pregnancy and risk of gestational diabetes mellitus in Chinese women: a prospective cohort study

We aimed to examine the association between the quantity and quality of dietary fat in early pregnancy and gestational diabetes mellitus (GDM) risk. In total, 1477 singleton pregnant women were included from Sichuan Provincial Hospital for Women and Children, Southwest China. Dietary information was collected by a 3-d 24-h dietary recall. GDM was diagnosed based on the results of a 75-g, 2-h oral glucose tolerance test at 24-28 gestational weeks. Log-binomial models were used to estimate relative risks (RR) and 95% CI. The results showed that total fat intake was positively associated with GDM risk (Q4 v. Q1: RR = 1·40; 95 % CI 1·11, 1·76; Ptrend = 0·001). This association was also observed for the intakes of animal fat and vegetable fat. After stratified by total fat intake (< 30 %E v. ≥ 30 %E), the higher animal fat intake was associated with higher GDM risk in the high-fat group, but the moderate animal fat intake was associated with reduced risk of GDM (T2 v. T1: RR = 0·65; 95 % CI 0·45, 0·96) in the normal-fat group. Vegetable fat intake was positively associated with GDM risk in the high-fat group but not in the normal-fat group. No association between fatty acids intakes and GDM risk was found. In conclusion, total fat, animal and vegetable fat intakes were positively associated with GDM risk, respectively. Whereas when total fat intake was not excessive, higher intakes of animal and vegetable fat were likely irrelevant with increased GDM risk, even the moderate animal fat intake could be linked to lower GDM risk.

Estimate of Dietary Total Antioxidant Capacity of Pregnant Women and Associated Factors

OBJECTIVE

 To investigate the dietary total antioxidant capacity (DTAC) of pregnant women, and associated factors.

METHODS

 Cross-sectional study conducted with 785 pregnant adult women attended in primary health care centers of Ribeirão Preto, state of São Paulo, Brazil. Two 24-hour dietary recalls were obtained, and the usual intake was estimated through the Multiple Source Method. The DTAC was estimated using the ferric reducing antioxidant power assay. The relationship between the higher DTAC estimate (≥ median of 4.3 mmol/day) and associated factors was investigated using adjusted logistic models with backward selection.

RESULTS

 In total, 25% of the pregnant women were classified as overweight, and 32% as obese. The median (P25, P75) DTAC was 4.3 (3.3-5.6) mmol/day. Through adjusted logistic regression models with backward selection, a higher chance of DTAC estimates above the median among pregnant women aged ≥ 35 years old (2.01 [1.24-3.27]) was verified when compared with younger pregnant women. Women with prepregnancy overweight (0.63 [0.45-0.89]) and obesity (0.59 [0.40-0.88]) presented a lower chance of DTAC estimates above the median when compared with eutrophic pregnant women. A higher DTAC estimate was positively associated with the use of dietary supplements (1.39 [1.03-1.88]), and negatively associated with total dietary energy (0.59 [0.42-0.85]).

CONCLUSION

 The DTAC estimate over the median was associated with greater age, adequate body weight, use of dietary supplements, and lower energy intake.

Promoting and Updating Food Frequency Questionnaire Tool to Measure Food Consumption and Nutrient Intake Analysis

Background:

One of the problems that nutritionists have always faced in research projects is the analysis of food intake of the subjects. Various approaches have been proposed in which the use of food frequency is one of the most used in this field. Many tools have been proposed in this area that aim of present research is to update and optimize one of the most common forms mentioned above.

Method:

In this study, we attempted to update and optimize the 147-item common food frequency questionnaire using USDA database. Moreover, the values of dietary antioxidant profiles, lipid ratios, dietary fat quality, atherogenic and thrombogenic indices, amino acids, flavonoids, and other requirements are included in the above tool to meet nutrition research needs.

Results:

The re-analysis of the obtained data with USDA Bank showed no difference due to the similarity of the source of information and the accuracy of the above instrument was confirmed.

Conclusion:

Due to the applicability of this tool, it can be recommended to researchers to use the above tool. We hope to see the Iranian database in the coming years to optimize the above tools based on the Iranian bank.

Changes of Plasma Phospholipid Fatty Acids Profiles in Pregnancy in Relation to the Diagnosis and Treatment of Gestational Diabetes Mellitus

BACKGROUND

Plasma phospholipid fatty acids (FAs) in early and mid-pregnancy have been prospectively related to gestational diabetes mellitus (GDM) risk. Yet, changes of FAs following GDM diagnosis and treatment and their implications for glucose metabolism and control remain understudied.

METHODS

From the Eunice Kennedy Shriver National Institute Child Health and Human Development Fetal Growth Studies-Singleton Cohort of 2802 pregnant women, we ascertained 85 GDM cases using the Carpenter and Coustan criteria and 85 non-GDM controls after exclusion. Using plasma collected before (23-31 weeks) and after GDM diagnosis (33-39 weeks), we quantified 25 saturated, poly- and monounsaturated FAs levels. We estimated the fold change of FAs before and after GDM diagnosis, using multiple linear mixed models adjusting for confounders.

RESULTS

Eight FAs showed significant fold changes from the baseline values (23-31 weeks) among GDM cases as compared to women without GDM. Five FAs showed reduced fold changes [myristic acid (14:0): β: -0.22 (95% CI: -0.30, -0.14), palmitic acid (16:0): β: -0.02 (95% CI: -0.04, -0.01), cis-palmitoleic acid (16:1n7): β: -0.15 (95% CI: -0.24, -0.05), alpha-linolenic acid (18:3n3): β: -0.19 (95% CI: -0.31, -0.07], and dihomo-gamma-linoleic acid (20:3n6): β:-0.16; 95% CI: -0.21, -0.11)], whereas 3 showed increases [heptadecanoic acid (17:0): β: 0.17 (95% CI: 0.11, 0.22), cis-vaccenic acid (18:1n7): β: 0.06 (95% CI: 0.03, 0.10), and arachidonic acid (20:4n6): β: 0.10 (95% CI: 0.06, 0.13)].

CONCLUSIONS

Our study identified 8 FAs with unique patterns of change before and after GDM diagnosis that differed significantly between women with and without GDM. Our findings may shed light on the role of FA metabolism in the pathophysiology and disease management and progression of GDM.

CLINICAL TRIAL REGISTRY

NCT00912132.

Early pregnancy plasma fatty acid profiles of women later diagnosed with gestational diabetes

INTRODUCTION

Fatty acid (FA) concentrations have previously been associated with gestational diabetes mellitus (GDM). However, few studies on GDM have examined FA profiles in early pregnancy or before diagnosis. This study aimed to compare early pregnancy plasma FA profiles of women with and without GDM diagnoses as well as their reported dietary consumption.

RESEARCH DESIGN AND METHODS

The subjects comprised 853 women from the prospective study: Pregnant Women in Iceland II (PREWICE II), attending their 11-14 weeks ultrasound appointment in 2017-2018. During the visit, blood samples were collected for plasma FA analysis, and dietary habits were assessed using a short food frequency questionnaire. Information on GDM diagnoses was then later extracted from medical records. Differences in FA profile between GDM cases and non-cases were evaluated using the Mann-Whitney U test.

RESULTS

GDM was diagnosed in 127 women (14.9%). Concentrations of saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids (PUFA) n-6, PUFA n-3 and total FA were higher in the women who later developed GDM compared with those who did not (p≤0.05). The medians for total FA were 2898 μg/mL for the women with GDM and 2681 μg/mL for those without GDM. Mean adjusted difference for total FA between the groups was 133 μg/mL (95% CI 33 to 233). Similar results were observed in prepregnancy normal-weight women and overweight women/women with obesity. Overall diet quality in early pregnancy appeared to be lower among the women later diagnosed with GDM.

CONCLUSION

We found that plasma FA profiles in early pregnancy were different for women later diagnosed with GDM compared with those who were not, independent of the women's body mass index.

Higher intakes of fruits and vegetables are related to fewer menopausal symptoms: a cross-sectional study

OBJECTIVES

The aim of this study was to explore the associations between fruit and vegetable (FV) intake, and its subgroups and menopausal symptoms along with its subtypes in postmenopausal women.

METHODS

This cross-sectional study included 393 postmenopausal women in municipality health centers in the south of Tehran, Iran. Sociodemographic data, dietary intakes, and anthropometric measures were obtained from individuals. Menopause rating scale (MRS) questionnaire was employed to measure menopausal symptoms. The total MRS score (TMRSS) was the sum of the somatic score (SS), psychological score (PS), and urogenital score (US). Participants were divided into low and high total MRS and its domain scores.

RESULTS

After adjustment for confounding variables, an inverse relationship was found between total FV with TMRSS (odds ratio [OR] 0.23, 95% confidence interval [CI] 0.06-0.81) and SS (OR 0.30, 95% CI 0.11-0.82). In addition, the consumption of total fruits was significantly related to lower SS (OR 0.27, 95% CI 0.10-0.71). Only intake of citrus fruits was inversely associated with TMRSS (OR 0.23, 95% CI 0.07-0.71) and SS (OR 0.28, 95% CI 0.11-0.70). Likewise, intakes of total FV (OR 2.46, 95% CI 1.37-4.41), total vegetables (OR 2.54, 95% CI 1.10-5.88), green leafy vegetables (OR 3.59, 95% CI 1.47-8.75), dark yellow vegetables (OR 2.28, 95% CI 1.00-5.18), other vegetables (OR 5.23, 95% CI 1.17-15.39), and citrus fruits were linked to higher US (OR 4.35, 95% CI 1.77-10.71).

CONCLUSION

The results of the present study showed that some FV subgroups had inverse associations with climacteric symptoms, whereas higher intake of some subgroups of FV appeared to be associated with more urogenital symptoms in postmenopausal women.

Relationship between the quality of the pregnant woman's diet and birth weight: a prospective cohort study

BACKGROUND

Birth weight is a relevant predictor of childhood health outcomes. Studies investigating the association between modifiable risk factors, as the maternal diet quality, and birth weight are needed. We aimed to investigate the association between the Diet Quality Index Adapted for Pregnant Women (IQDAG) score and birth weight.

METHODS

This is a prospective cohort that includes 547 Brazilian mother-child pairs. Dietary recalls and a food frequency questionnaire were obtained during pregnancy. Information on birth weight, sex, and gestation duration were obtained from the Live Birth Information System (SINASC).

RESULTS

On total, 3.8% of the newborns were classified as low birth weight (LBW), 6.0% with macrosomia, 10.2% small for gestational age (SGA), and 11.2% large for gestational age (LGA). The mean (SD) IQDAG score was 70.1 (11.8). Adjusted logistic regression models showed that women in the third tertile of the IQDAG score presented a lower risk of having LGA babies [OR 0.44 (95% CI 0.22, 0.90), p-trend = 0.02] compared to the first tertile. Women in the third tertile of omega-3 intake presented a lower risk of giving birth to LGA infants [OR 0.33 (95% CI 0.15, 0.69), p-trend = 0.00] and LBW infants [OR 0.18 (95% CI 0.04, 0.83), p-trend = 0.02] when compared to the first tertile. There was also a lower SGA trend among the children of women in the third tertile of omega-3 intake [OR 0.43 (95% CI 0.17, 1.07), p-trend = 0.03] compared to the first tertile.

CONCLUSION

A better diet quality and higher omega-3 intake are protective factors for LGA babies, and increased maternal omega-3 intake reduce the risk of LBW and LGA, and may be a protective factor against the birth of SGA infants.

Dietary Cholesterol Intake and Risk of Gestational Diabetes Mellitus: A Meta-Analysis of Observational Studies

This meta-analysis aimed to understand the association between dietary cholesterol intake and the risk of gestational diabetes mellitus (GDM). We systematically searched the PubMed, Web of Science, and EMBASE databases to identify observational studies, published before September 2020, investigating the relationship between dietary cholesterol intake and risk of GDM. After evaluating the heterogeneity among studies, we used fixed- or random-effects models to calculate pooled values of relative risk (RR) and 95% confidence intervals (CIs) in order to estimate the effect of dietary cholesterol on the risk of GDM. We included a total of 9 studies (3 cohort, 4 cross-sectional, and 2 case-control) involving 30123 participants and 3237 cases. The pooled RR of GDM comparing highest versus lowest category of dietary cholesterol intake was 1.49 (95% CI, 1.18-1.88). The dose-response relationship showed that the risk of GDM increased by 32% (RR = 1.32; 95% CI, 1.20-1.45) for every increase of 100 mg per day in dietary cholesterol intake. This meta-analysis indicates that an increase in dietary cholesterol intake is associated with increased risk of GDM. Detailed cohort studies are essential to gain a better understanding of this association. Key teaching pointsStudies on animal models have suggested that a cholesterol-rich diet can promote systemic inflammation and insulin resistance, both of which can contribute to T2DM and GDM.Several epidemiological studies have investigated a potential relationship between dietary cholesterol intake and GDM risk, and the results are controversial.Our meta-analysis indicates that increased dietary cholesterol intake is associated with increased GDM risk.Dose-response analysis showed a linear relationship between dietary cholesterol intake and risk of GDM.

Dietary Fat Quality and Pre-diabetes: A Case-control Study

Background:

The relationship between dietary fat quality (DFQ) indices and pre-diabetes has not been well studied. This study aimed to determine the association of DFQ indices and fatty acid intake with pre-diabetes.

Methods:

This case-control study included 150 subjects with normal fasting blood glucose (FBG) and 147 pre-diabetic subjects. Dietary intake was assessed by a validated food-frequency questionnaire. DFQ indices including atherogenicity (AI) and thrombogenicity (TI), the ratios of hypo- and hypercholesterolemic (h:H), polyunsaturated:saturated (P:S) and n-3:n-6 polyunsaturated fatty acids were calculated. FBG test and 2-hour oral glucose tolerance test (OGTT) were measured.

Results:

After adjustment for some confounding variables, a positive association was found between intake of total saturated fatty acids (SFA), myristic acid, palmitic acid, and pre-diabetes, and a negative association was observed among n-3 polyunsaturated fatty acids, eicosapentaenoic, docosahexaenoic and arachidonic acids intake and pre-diabetes. AI was found to be positively associated with pre-diabetes (OR 6.68, 95% CI 2.57-17.34). An inverse relationship was observed between n-3:n-6 (OR 0.37, 95% CI 0.14-0.93) and h:H (OR 0.20, 95% CI 0.07-0.52) ratios with pre-diabetes.

Conclusions:

Higher intake of dietary n-3 fatty acids was adversely, whereas SFA intake was positively related to pre-diabetes morbidity. DFQ indices may be a useful measure to investigate fat intakes and blood glucose disturbances.

Biochemical and Nutritional Evaluation of Chlorella and Auxenochlorella Biomasses Relevant for Food Application

Microalgae are a source of potentially healthy and sustainable nutrients. However, the bioaccessibility of these nutrients remains uncertain. In this study, we analyzed the biomass composition of five commercial Chlorella and Auxenochlorella strains, and Chlorella vulgaris heterotrophically cultivated in our laboratory. Protein accounted for 65 ± 3% (w w^-1) dry matter (DM) in all biomasses, except for the lab-grown C. vulgaris that contained 20% (w w^-1) DM protein. The fatty acids content was comparable and ranged between 7 and 10% (w w^-1) DM. Most of the biomasses had a ω6-polyunsaturated fatty acids (PUFAs)/ω3-PUFAs ratio <4, as recommended by nutritional experts. A recently published harmonized protocol for in vitro digestion was used to evaluate fatty acids and protein bioaccessibilities. Protein bioaccessibility ranged between 60 and 74% for commercial Chlorella and Auxenochlorella biomasses and was 43% for the lab-grown C. vulgaris. Fatty acids bioaccessibility was <7% in commercial biomasses and 19% in the lab-grown C. vulgaris. Taken together, the results show that microalgae are promising sources of bioaccessible protein. The limited fatty acids bioaccessibility indicates the need for alternative upstream and downstream production strategies.

Dietary total antioxidant capacity during pregnancy and birth outcomes

PURPOSE

To investigate the effect of maternal dietary total antioxidant capacity (DTAC) and main food sources on the risk of preterm birth (PB) and offspring birth size.

METHODS

Cohort study that included 733 Brazilian mother-child pairs. Two 24 h dietary recalls were obtained during pregnancy and the usual intake was estimated through the Multiple Source Method. Data of the offspring were extracted from the national live births information system. Adjusted multivariable logistic regression models were used to investigate the relationship that energy-adjusted DTAC and food sources have with the outcomes.

RESULTS

In total, 9.7% of the children were PBs, 6.0% were born with low birth weight (LBW), 6.7% with macrosomia, 9.3% were small for gestational age (SGA) and 16.4% large for gestational age (LGA). The mean energy-adjusted DTAC ± SD was 4.7 ± 2.1 mmol. The adjusted OR (95%CI) of PB for each increasing tertile of maternal DTAC were 0.71 (0.41, 1.30) and 0.54 (0.29, 0.98), when compared with the lowest intake. For LBW, these were 0.25 (0.09, 0.65) and 0.63 (0.28, 1.41). A likelihood of lower odds for PB was found for a higher intake of fruits [0.66 (0.39, 1.09)]. Women with a higher consumption of milk were less likely to have a child with LBW [0.48 (0.23, 1.01)], and children whose mothers reported a higher intake of beans had lower odds of being born LGA [0.61 (0.39, 0.93)].

CONCLUSION

The data suggest that a higher intake of foods with antioxidant activity during pregnancy might reduce the chance of adverse birth outcomes.

Dietary fat quantity and quality in relation to general and abdominal obesity in women: a cross-sectional study from Ghana

BACKGROUND

Although relationships between obesity and total fat and fat types have been widely examined, the associations between the relative proportions of fatty acids calculated in the form of indices and obesity/overweight are lacking. The objective of this study was to assess associations between dietary fat quality indices and odds of obesity/overweight in women from Ghana.

METHODS

In this cross-sectional study, dietary information was obtained using 24-h dietary recall. The odds of obesity were evaluated across quintiles of specific DFQ indices [atherogenicity index (AI), thrombogenic index (TI), hypo- and hypercholesterolemic fatty acids ratio (h/H), omega-3 to omega-6 polyunsaturated fatty acids ratio (∑ω-3/∑ω-6), polyunsaturated fatty acids/saturated fatty acids ratio (PSR), dietary lipophilic index (LI) and percentage of energy from total fat (TF)].

RESULTS

After adjustment for covariates, general obesity and overweight were inversely associated with ∑ω-3/∑ω-6 ratio (OR: 0.63; 95% CI: 0.24-1.63; P for trend (P) = 0.005) and positively with TI (4.14; 95% CI: 1.78-9.66; P = 0.01) and LI (2.49; 95% CI: 1.14-5.43; P = 0.01). The odds of abdominal obesity based on waist circumference (WC) were significantly higher among participants in the fifth quintile (Q) compared with those in the first Q of AI (1.24; 95% CI: 0.56-2.74; P = 0.01), TI (4.14; 95% CI: 1.78-9.66; P = 0.009), LI (2.11; 95% CI: 0.98-4.55; P = 0.02) and TF (1.59; 95% CI: (0.73-3.46; P = 0.003). Similarly, waist to height ratio (WHtR) was positively associated with AI (2.89; 95% CI: 1.32-6.31; P = 0.04), TI (2.65; 95% CI: 1.22-5.76; P = 0.03), LI (3.32; 95% CI: 1.52-7.28; P = 0.007) and TF (1.83; 95% CI: 0.85-3.93; P = 0.009).

CONCLUSION

There was an inverse association between ∑ω-3/∑ω-6 ratio and general obesity and WC. We also found positive associations between abdominal obesity and AI and TF. Furthermore, TI and LI showed positive relationships with both general and abdominal obesity. Therefore, intake of dietary fatty acids in favor of higher ratios of ∑ω-3/∑ω-6 may be important in obesity prevention.

Relationship between minimally and ultra-processed food intake during pregnancy with obesity and gestational diabetes mellitus

This study aimed to investigate the relationship between food intake (considering the nature, extent, and purpose of food processing) during pregnancy and overweight, obesity, and gestational diabetes mellitus conditions. This is a cross-sectional study conducted among 785 adult women in singleton pregnancies (between 24th and 39th weeks of gestation) in Brazil. Usual food intake was estimated by the Multiple Source Method, using two 24-hour dietary recalls. The food groups of interest in this study were the unprocessed or minimally processed foods and ultra-processed foods. The World Health Organization criteria for the diagnosis of gestational diabetes mellitus and the Atalah criteria for excess weight were used. Adjusted multinomial logistic regression models were used to assess the relationship between energy contribution (%E) from foods with overweight and obesity conditions and, adjusted logistic regression models for gestational diabetes mellitus. In total, 32.1% participants were overweight, 24.6% were obese, and 17.7% of women were diagnosed with gestational diabetes mellitus . After adjustments, an inverse association between the highest tertile of %E from the intake of unprocessed or minimally processed foods and obesity was found [0.49 (0.30-0.79)]. Moreover, a positive association between the highest tertile of %E from ultra-processed food intake [3.06 (1.27-3.37)] and obesity was observed. No association between food intake (considering the nature, extent, and purpose of food processing) during pregnancy and overweight or gestational diabetes mellitus was found. The findings suggest a role of food processing in obesity but not in gestational diabetes mellitus. Further research is warranted to provide robust evidence on the relationship between the role of processed foods in obesity and gestational diabetes mellitus.

The role of food processing in the inflammatory potential of diet during pregnancy

The aim was to investigate the relationship between the energy contribution (E%) of foods according to the degree of industrial processing and the energy-adjusted dietary inflammatory index (E-DII) in pregnancy. Two 24-hour dietary recalls were obtained from each of the 784 pregnant women. Adjusted linear regression models allowed observing an inverse association between E-DII scores and E% from minimally processed foods β = -0.049 (95%CI -0.055- -0.042) and a direct association with the E% of ultra-processed foods β = 0.052 (95%CI 0.045-0.058), indicating a relationship between the dietary inflammatory potential and the degree of industrial processing of foods.

The significant role of carnitine and fatty acids during pregnancy, lactation and perinatal period. Nutritional support in specific groups of pregnant women

BACKGROUND & AIMS

Pregnancy is characterized by a complexity of metabolic processes that may impact fetal health and development. Women's nutrition during pregnancy and lactation is considered important for both mother and infant. This review aims to investigate the significant role of fatty acids and carnitine during pregnancy and lactation in specific groups of pregnant and lactating women.

METHODS

The literature was reviewed using relevant data bases (e.g. Pubmed, Scopus, Science Direct) and relevant articles were selected to provide information and data for the text and associated Tables.

RESULTS

Dynamic features especially of plasma carnitine profile during pregnancy and lactation, indicate an extraordinarily active participation of carnitine in the intermediary metabolism both in pregnant woman and in neonate and may also have implications for health and disease later in life. Maternal diets rich in trans and saturated fatty acids can lead to impairments in the metabolism and development of the offspring, whereas the consumption of long chain-polyunsaturated fatty acids during pregnancy plays a beneficial physiologic and metabolic role in the health of offspring.

CONCLUSIONS

Pregnant women who are underweight, overweight or obese, with gestational diabetes mellitus or diabetes mellitus and those who choose vegan/vegetarian diets or are coming from socially disadvantaged areas, should be nutritionally supported to achieve a higher quality diet during pregnancy and/or lactation.

Association of dietary patterns and degree of food processing with feelings of depression in pregnancy

Abstract Objectives: to investigate the relationship of dietary patterns and degree of food processing with feelings of depression in pregnancy. Methods: cross-sectional study conducted with 784 adult pregnant women in Ribeirão Preto, SP, between 2011 and 2012. Feelings of depression were obtained through a structured questionnaire. Two 24-hour dietary recalls were obtained (24th-39th weeks of gestation) and adjusted through the Multiple Source Method. Four dietary patterns were determined: “Brazilian traditional”,“snacks”, “coffee”, and “healthy”. Adjusted logistic regression models were used to assess the relationship ofthe tertiles of dietary patterns and energy contribution (% E) of foods according to the degree of industrial processing with feelings of depression (always/most of the time vs. sometimes/never). Results: 12% of the women reported feelings of depression during the pregnancy. Women with greater adherence to “Brazilian traditional”[OR= 0.54 (CI95%= 0.30-0.97)] and “healthy” patterns [0.53 (0.30-0.94)] and with higher % E from minimally processed foods [0.51 (0.28-0.93)] presented a lower chance of feelings of depression. A higher % E from ultra-processed foods [2.39 (1.29-4.41)] was directly associated with the outcome. No associations with the other patterns were found. Conclusions: greater adherence to the“Brazilian traditional” and “healthy” dietary patterns was inversely associated with feelings of depression during pregnancy, possibly mediated by the degree of industrial processing of the foods.

Nutritional Supplementation for the Prevention and/or Treatment of Gestational Diabetes Mellitus

PURPOSE OF REVIEW

Gestational diabetes mellitus (GDM) is a common pregnancy complication that has short- and long-term health implications for both the mother and child. While lifestyle modifications, insulin therapy, and oral agents such as metformin are effective, they can be difficult to adhere to, and there remain concerns over long-term effects of oral agents on the infant. Further, GDM has no proven preventive strategies, which could be more effective than treatment postdiagnosis. Nutritional supplements are an appealing, potentially safer, and better tolerated alternative to pharmaceuticals to treat and/or prevent GDM. Here, we review the existing evidence for nutritional supplementation for treatment and prevention of GDM.

RECENT FINDINGS

There is limited evidence that myo-inositol, vitamins D and B6, magnesium, selenium, zinc, fatty acids, and probiotics might be beneficial for the prevention or treatment of GDM. There are very few studies for each nutrient, and the existing studies tend to have few participants. Where multiple studies of a nutrient exist, often those studies were conducted within the same country, limiting the generalizability of the findings, or alternatively there was no consensus across findings. There is limited evidence that nutritional supplementation of myo-inositol, vitamins D and B6, magnesium, selenium, zinc, fatty acids, and probiotics could improve glycemic control or prevent GDM. Our understanding is constrained by the small number of studies, small sample sizes in most studies, and by lack of consistency across findings. Further large, high-quality, randomized controlled trials are required to determine the efficacy of nutritional supplements to treat or prevent GDM.

Dietary patterns of pregnant women, maternal excessive body weight and gestational diabetes

OBJECTIVE

To investigate the relationship between the dietary patterns of pregnant women with maternal excessive body weight and gestational diabetes mellitus.

METHODS

A cross-sectional study conducted with a convenience sample of 785 adult pregnant women attended by the Unified Health System of Ribeirão Preto, state of São Paulo, between 2011 and 2012. Two 24-hour dietary recalls, corrected by the multiple source method, were employed . For the classification of the body mass index and the diagnosis of gestational diabetes mellitus, the criteria by Atalah and the World Health Organization were used, respectively. Dietary patterns were obtained by principal component analysis using the Varimax rotation method. The relationship between adherence to patterns, overweight and obesity was analyzed by multinomial logistic regression models and the relationship with gestational diabetes mellitus by adjusted unconditional logistic regression models.

RESULTS

We identified four dietary patterns: "traditional Brazilian"; "snacks"; "coffee" and "healthy". Women with a higher adherence to the "Healthy" (OR = 0.52; 95%CI 0.33-0.83) and "Brazilian Traditional" patterns (OR = 0.61; 95%CI 0.38-0.96) presented a lower chance of obesity, when compared to women with lower adherence, regardless of confounding factors. After adjustment for maternal excessive body weight, there was no association between dietary patterns and gestational diabetes mellitus.

CONCLUSIONS

Among the pregnant women, greater adherence to "traditional Brazilian" and "healthy" patterns was inversely associated with obesity, but no relationship was identified with gestational diabetes mellitus after adjusting for excessive body weight. Prospective studies are recommended to investigate the relationship between dietary patterns, overweight and gestational diabetes mellitus, reducing the chance of reverse causality.

Association between the Diet Quality Index Adapted for Pregnant Women (IQDAG) and excess maternal body weight

Abstract Objectives: to investigate the relationship between the Diet Quality Index Adapted for Pregnant Women (IQDAG) and excess maternal body weight. Methods: a cross-sectional study was conducted with 754 adult pregnant women, in Ribeirão Preto, São Paulo, between 2011 and 2012. The criteria proposed by Atalah were used to classify the body mass index (BMI). Adjusted multinomial logistic regression models were employed to investigate the relationship between the IQDAG and being overweight and obese, estimating the odds ratio (OR) and the 95% confidence interval (CI95%). Results: the mean (SD) age of women was 28 (5) years, 33.4% were overweight and 25.6% obese. The pregnant women with higher scores in the IQDAG were less likely to be overweight [OR= 0.56 (CI95% = 0.37-0.85)] or obese [0.43 (0.26-0.71)]; those with higher scores in the "Fiber" [0.51 (0.33; 0.78)] and "Iron" [0.62 (0.40-0.96)] components were less likely to be overweight. However, women with higher scores in the percentage of energy from ultra-processed foods were more likely to be overweight [1.72 (1.10-2.94)] or obese [5.24 (2.80-9.80)], when compared to women with lower scores. Conclusions: poorer quality maternal diets were observed among the women who were overweight and obese during pregnancy.

The relationship of flavonoid intake during pregnancy with excess body weight and gestational diabetes mellitus

OBJECTIVE

To investigate the relationship of flavonoid intake during pregnancy with maternal excessive body weight and gestational diabetes mellitus (GDM).

SUBJECTS AND METHODS

A cross-sectional study was conducted among 785 adult women in singleton pregnancies, and data were collected at the time of the oral glucose tolerance test. For the body mass index (BMI) classification according to the gestational age, the criteria of Atalah was used, and the diagnosis of GDM was based on the World Health Organization of 2014. Two 24-hour dietary recalls were obtained, and the usual intake was determined by the Multiple Source Method. Adjusted multinomial logistic regression was used to investigate the relationship of the flavonoids with overweight and obesity, and adjusted non-conditional logistic regression for the relationship of the flavonoids with GDM.

RESULTS

The mean (SD) age of the women was 28 (5) years, 32.1% were overweight, 24.6% were obese and 17.7% were diagnosed with GDM. The median (P25, P75) of total flavonoid intake was 50 (31,75) mg/day. Considering the eutrophic women as the reference, the pregnant women with a higher total flavonoid intake [OR 0.62 (95% CI 0.38; 0.96)] and anthocyanidin intake [OR 0.62 (95% CI 0.40; 0.99)] were less likely to be obese when compared to the women with lower intakes. No association of the flavonoids intake with overweight or GDM was found.

CONCLUSION

A very low intake of flavonoids was observed. The data suggest that the intake of foods naturally rich in total flavonoids and anthocyanidin has a beneficial role regarding obesity among pregnant women.

Dietary Patterns during Pregnancy Are Associated with the Risk of Gestational Diabetes Mellitus: Evidence from a Chinese Prospective Birth Cohort Study

Dietary patterns during pregnancy have been shown to influence the development of gestational diabetes mellitus (GDM). However, evidence from Asian populations is limited and inconsistent. We conducted a prospective cohort study in China to assess the relationship between dietary patterns and GDM. We administered three-day food diaries (TFD) and food frequency questionnaires (FFQ) at the second trimester. GDM was diagnosed with a 75 g 2-h oral glucose tolerance test at 24–28 weeks of gestation. We identified dietary patterns using principal components analysis and used multivariable logistic regression to investigate associations of dietary patterns with GDM. Of the 1014 participants, 23.5% were diagnosed with GDM. Both the TFD and FFQ identified a “traditional pattern”, consisting of high vegetable, fruit, and rice intake, which was associated with a lower GDM risk (odds ratio (OR) for quartile 4 versus quartile 1: 0.40, 95% CI: 0.23–0.71 for traditional pattern (TFD); OR: 0.44, CI: 0.27–0.70 for traditional pattern (FFQ)). The protective associations were more pronounced among women ≥35 years old. A whole grain–seafood TFD pattern was associated with higher risk of GDM (OR: 1.73, 95% CI: 1.10–2.74). These findings may provide evidence for making dietary guidelines among pregnant women in Chinese populations to prevent GDM.

A prospective and longitudinal study of plasma phospholipid saturated fatty acid profile in relation to cardiometabolic biomarkers and the risk of gestational diabetes

Background

Data on saturated fatty acids (SFAs) in relation to metabolic function and glucose homeostasis remain controversial. Such data are lacking among pregnant women.

Objective

We prospectively investigated objectively measured individual and subclasses of plasma phospholipid SFAs throughout pregnancy in relation to cardiometabolic markers and gestational diabetes mellitus (GDM) risk.

Design

Within the National Institute of Child Health and Human Development Fetal Growth Studies-Singleton Cohort of 2802 singleton pregnancies, 107 GDM cases were ascertained via medical record review and matched to 214 non-GDM controls on age, race/ethnicity, and gestational week (GW) at blood collection. Individual plasma phospholipid SFA concentrations were repeatedly measured throughout pregnancy at GWs 10-14, 15-26, 23-31, and 33-39 and also grouped into subclasses of even- or odd-chain SFAs.

Results

From GW 10, even-chain SFA concentrations were significantly higher among women who later developed GDM, whereas odd-chain SFAs were significantly lower among GDM cases compared with controls. At GWs 10-14, the SFA palmitic acid (16:0) was positively associated with impaired insulin resistance and cardiometabolic markers and the risk of GDM [adjusted OR comparing the highest with the lowest quartile (aORQ4-Q1): 4.76; 95% CI: 1.72, 13.10; P-trend = 0.001]. In contrast, odd-chain SFAs were inversely related to the previously mentioned markers and GDM risk [aORQ4-Q1 for pentadecanoic acid (15:0): 0.32; 95% CI: 0.11, 0.92; P-trend = 0.025; for heptadecanoic acid (17:0): 0.20; 95% CI: 0.07, 0.58; P-trend = 0.003]. Women with high (median or greater) even-chain SFA concentrations and low (less than median) odd-chain SFAs had a 9.43-fold (95%: CI 3.26-, 27.30-fold) increased risk compared with women with low even-chain and high odd-chain SFA concentrations. Similar results were observed at GWs 15-26.

Conclusions

The study provided one of the first lines of evidence suggesting that circulating concentrations of SFAs varying by SFA chain length, as early as GWs 10-14, were significantly and differentially associated with subsequent risk of GDM. Our findings highlight the importance of assessing objectively measured, individual, and subclasses of SFAs to investigate their distinct biological and pathophysiologic roles in glucose homeostasis and cardiometabolic outcomes. This study was registered at www.clinicaltrials.gov as NCT00912132.

Development of a Diet Quality Index Adapted for Pregnant Women

OBJECTIVE:

To develop a Diet Quality Index Adapted for Pregnant Women (IQDAG) and to evaluate its relation with the characteristics of women treated at the Brazilian Unified Health System.

METHODS:

The data on food intake come from a cross-sectional study carried out with 785 adult pregnant women in the city of Ribeirão Preto, state of São Paulo, Brazil, between 2011 and 2012. The index was based on the recommendations of the Brazilian Ministry of Health, previous national dietary indexes, and the new Dietary Guidelines for the Brazilian Population. We used the ANOVA, Kruskal-Wallis, and chi-square tests to describe the quality of the diet according to the characteristics of the mother.

RESULTS:

The IQDAG has nine components, and it is represented by three food groups (in servings/1,000 kcal), five nutrients, and a moderator component. A high proportion of pregnant women reached the maximum score for the components of legumes and vegetables. However, few women reached the maximum score for consumption of fresh fruits, fiber, omega-3, calcium, folate, iron, and ultra-processed foods. We verified a better quality of diet among older and eutrophic pregnant women who reported practicing more physical activity and taking dietary supplements. We also observed the highest index score among women with higher intake of carbohydrates, proteins, vitamins C, E, and A, and minerals calcium, folate, and iron, as well as among those with lower intake of total fats and saturated fats.

CONCLUSIONS:

This dietary index is unprecedented in incorporating the recommendation of the new Dietary Guidelines for the Brazilian Population regarding the moderation of the consumption of ultra-processed foods. It was useful in evaluating the quality of the diet of pregnant women and we verified a higher score among older and eutrophic women who reported a healthy lifestyle. Strategies are needed to promote a higher consumption of fresh fruits, foods high in fiber, omega-3, calcium, folate, iron, and minimally processed foods in pregnant women.

Fat Quality Index and Risk of Cardiovascular Disease in the Sun Project

OBJECTIVES

To examine the association between a dietary fat quality index (FQI), and the risk of incident cardiovascular events or deaths in the Seguimiento Universidad de Navarra (SUN) cohort.

DESIGN

Longitudinal analysis during 10.1 years of median follow-up. Cox models were used to estimate adjusted hazard ratios (HR) of incident cardiovascular diseases (CVD) according to tertiles of FQI and of different fat subtypes.

SETTING

University of Navarra, Spain.

PARTICIPANTS

19,341 middle-aged adults.

MEASUREMENTS

Fat intake was measured with a validated food-frequency questionnaire. The FQI was calculated according to the ratio: (monounsaturated+polyunsaturated) / (saturated+trans fatty acids).

RESULTS

We observed 140 incident cases of CVD. No association was found for FQI (HR=0.94, 95 %CI 0.61-1.47 for the highest vs the lowest tertile, p for trend=0.884). No significant associations were found for different dietary fat subtypes on CVD risk. The results suggest no clear association between a higher FQI and a higher amount of energy from fat and incidence of CVD (p for interaction: 0.259 and p for trend only among participants with a percentage of energy from fat ≥35% of total energy: 0.272).

CONCLUSION

In this Mediterranean cohort, the FQI was not associated with cardiovascular events. A "heart-healthy diet" should focus its attention on dietary fat sources and should use an overall dietary pattern approach, rather than limiting the focus on fat subtypes. More research is needed to validate dietary advice on specific fatty acids intake or saturated fatty acids replacements for reducing CVD risk.

From Sea to Shining Sea and the Great Plains to Patagonia: A Review on Current Knowledge of Diabetes Mellitus in Hispanics/Latinos in the US and Latin America

The past two decades have witnessed many advances in the prevention, treatment, and control of diabetes mellitus (DM) and its complications. Increased screening has led to a greater recognition of type 2 diabetes mellitus (type 2 DM) and prediabetes; however, Hispanics/Latinos, the largest minority group in the US, have not fully benefited from these advances. The Hispanic/Latino population is highly diverse in ancestries, birth places, cultures, languages, and socioeconomic backgrounds, and it populates most of the Western Hemisphere. In the US, the prevalence of DM varies among Hispanic/Latino heritage groups, being higher among Mexicans, Puerto Ricans, and Dominicans, and lower among South Americans. The risk and prevalence of diabetes among Hispanics/Latinos are significantly higher than in non-Hispanic Whites, and nearly 40% of Hispanics/Latinos with diabetes have not been formally diagnosed. Despite these striking facts, the representation of Hispanics/Latinos in pharmacological and non-pharmacological clinical trials has been suboptimal, while the prevalence of diabetes in these populations continues to rise. This review will focus on the epidemiology, etiology and prevention of type 2 DM in populations of Latin American origin. We will set the stage by defining the terms Hispanic, Latino, and Latin American, explaining the challenges identifying Hispanics/Latinos in the scientific literature and databases, describing the epidemiology of diabetes-including type 2 DM and gestational diabetes mellitus (GDM)-and cardiovascular risk factors in Hispanics/Latinos in the US and Latin America, and discussing trends, and commonalities and differences across studies and populations, including methodology to ascertain diabetes. We will discuss studies on mechanisms of disease, and research on prevention of type 2 DM in Hispanics/Latinos, including women with GDM, youth and adults; and finalize with a discussion on lessons learned and opportunities to enhance research, and, consequently, clinical care oriented toward preventing type 2 DM in Hispanics/Latinos in the US and Latin America.

Alterations of fatty acid profiles in gestational diabetes and influence of the diet

Gestational diabetes mellitus (GDM) is a pregnancy-induced complication with increased prevalence, especially in overweight women. Fatty acid (FA) composition in tissues can reflect dietary fat intake, especially essential FA intake. Moreover, it has been shown that FA profiles in blood lipid fractions are altered in diabetic patients. Consequently, women with GDM may also have a distinctive FA profile. The objective of this review is compare FA profiles in different blood lipid fractions and the influence of dietary fat intake in women with GDM or normoglycemic pregnancies. Results show that women with GDM have more saturated and less polyunsaturated FA (PUFA) in their red blood cell (RBC) membranes than normoglycemic pregnant women. Moreover, some studies reported that women with GDM have a greater energy intake from total fat and saturated FA, along with a lower energy intake from PUFA, when compared to normoglycemic pregnancies. Clinical trials showed that omega-3 PUFA levels in RBC membranes of GDM women can be restored by a dietary intervention. Further research is required to determine whether FA profiles are altered prior to the diagnosis of GDM and can be prevented by diet.

Dietary advice interventions in pregnancy for preventing gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is a form of diabetes occurring during pregnancy which can result in short- and long-term adverse outcomes for women and babies. With an increasing prevalence worldwide, there is a need to assess strategies, including dietary advice interventions, that might prevent GDM.

OBJECTIVES

To assess the effects of dietary advice interventions for preventing GDM and associated adverse health outcomes for women and their babies.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (3 January 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs assessing the effects of dietary advice interventions compared with no intervention (standard care), or to different dietary advice interventions. Cluster-RCTs were eligible for inclusion but none were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of the included studies. Data were checked for accuracy. The quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We included 11 trials involving 2786 women and their babies, with an overall unclear to moderate risk of bias. Six trials compared dietary advice interventions with standard care; four compared low glycaemic index (GI) with moderate- to high-GI dietary advice; one compared specific (high-fibre focused) with standard dietary advice. Dietary advice interventions versus standard care (six trials) Considering primary outcomes, a trend towards a reduction in GDM was observed for women receiving dietary advice compared with standard care (average risk ratio (RR) 0.60, 95% confidence interval (CI) 0.35 to 1.04; five trials, 1279 women; Tau² = 0.20; I² = 56%; P = 0.07; GRADE: very low-quality evidence); subgroup analysis suggested a greater treatment effect for overweight and obese women receiving dietary advice. While no clear difference was observed for pre-eclampsia (RR 0.61, 95% CI 0.25 to 1.46; two trials, 282 women; GRADE: low-quality evidence) a reduction in pregnancy-induced hypertension was observed for women receiving dietary advice (RR 0.30, 95% CI 0.10 to 0.88; two trials, 282 women; GRADE: low-quality evidence). One trial reported on perinatal mortality, and no deaths were observed (GRADE: very low-quality evidence). None of the trials reported on large-for-gestational age or neonatal mortality and morbidity.For secondary outcomes, no clear differences were seen for caesarean section (average RR 0.98, 95% CI 0.78 to 1.24; four trials, 1194 women; Tau² = 0.02; I² = 36%; GRADE: low-quality evidence) or perineal trauma (RR 0.83, 95% CI 0.23 to 3.08; one trial, 759 women; GRADE: very low-quality evidence). Women who received dietary advice gained less weight during pregnancy (mean difference (MD) -4.70 kg, 95% CI -8.07 to -1.34; five trials, 1336 women; Tau² = 13.64; I² = 96%; GRADE: low-quality evidence); the result should be interpreted with some caution due to considerable heterogeneity. No clear differences were seen for the majority of secondary outcomes reported, including childhood/adulthood adiposity (skin-fold thickness at six months) (MD -0.10 mm, 95% CI -0.71 to 0.51; one trial, 132 children; GRADE: low-quality evidence). Women receiving dietary advice had a lower well-being score between 14 and 28 weeks, more weight loss at three months, and were less likely to have glucose intolerance (one trial).The trials did not report on other secondary outcomes, particularly those related to long-term health and health service use and costs. We were not able to assess the following outcomes using GRADE: postnatal depression; maternal type 2 diabetes; neonatal hypoglycaemia; childhood/adulthood type 2 diabetes; and neurosensory disability. Low-GI dietary advice versus moderate- to high-GI dietary advice (four trials) Considering primary outcomes, no clear differences were shown in the risks of GDM (RR 0.91, 95% CI 0.63 to 1.31; four trials, 912 women; GRADE: low-quality evidence) or large-for-gestational age (average RR 0.60, 95% CI 0.19 to 1.86; three trials, 777 babies; Tau² = 0.61; P = 0.07; I² = 62%; GRADE: very low-quality evidence) between the low-GI and moderate- to high-GI dietary advice groups. The trials did not report on: hypertensive disorders of pregnancy; perinatal mortality; neonatal mortality and morbidity.No clear differences were shown for caesarean birth (RR 1.27, 95% CI 0.79 to 2.04; two trials, 201 women; GRADE: very low-quality evidence) and gestational weight gain (MD -1.23 kg, 95% CI -4.08 to 1.61; four trials, 787 women; Tau² = 7.31; I² = 90%; GRADE: very low-quality evidence), or for other reported secondary outcomes.The trials did not report the majority of secondary outcomes including those related to long-term health and health service use and costs. We were not able to assess the following outcomes using GRADE: perineal trauma; postnatal depression; maternal type 2 diabetes; neonatal hypoglycaemia; childhood/adulthood adiposity; type 2 diabetes; and neurosensory disability. High-fibre dietary advice versus standard dietary advice (one trial) The one trial in this comparison reported on two secondary outcomes. No clear difference between the high-fibre and standard dietary advice groups observed for mean blood glucose (following an oral glucose tolerance test at 35 weeks), and birthweight.

AUTHORS' CONCLUSIONS

Very low-quality evidence from five trials suggests a possible reduction in GDM risk for women receiving dietary advice versus standard care, and low-quality evidence from four trials suggests no clear difference for women receiving low- versus moderate- to high-GI dietary advice. A possible reduction in pregnancy-induced hypertension for women receiving dietary advice was observed and no clear differences were seen for other reported primary outcomes. There were few outcome data for secondary outcomes.For outcomes assessed using GRADE, evidence was considered to be low to very low quality, with downgrading based on study limitations (risk of bias), imprecision, and inconsistency.More high-quality evidence is needed to determine the effects of dietary advice interventions in pregnancy. Future trials should be designed to monitor adherence, women's views and preferences, and powered to evaluate effects on short- and long-term outcomes; there is a need for such trials to collect and report on core outcomes for GDM research. We have identified five ongoing studies and four are awaiting classification. We will consider these in the next review update.