BACKGROUND:Functional gastrointestinal disorders (FGIDs) are highly prevalent among infants. Exclusive breastfeeding has been consistently associated with better gastrointestinal health. However, current evidence regarding the associations between early feeding practices and infant gastrointestinal development remains limited. OBJECTIVES:To examine the associations between early feeding practices at 1 month of age and gastrointestinal symptoms and overall gastrointestinal burden in infants during the first 12 months of life. METHODS:In this multicenter prospective cohort study, 669 healthy mother-infant pairs were finally included. According to feeding practices at 1 month of age, infants were categorized into three groups: exclusive direct breastfeeding (EDB, n = 236, 35.28%), bottle-fed expressed breastmilk (EBB, n = 150, 22.42%), and mixed feeding (MF, n = 283, 42.30%). Gastrointestinal (GI) symptoms were assessed using the Infant Gastrointestinal Symptom Questionnaire (IGSQ) and symptom items from the PedsQL™ Infant Scales. Generalized estimating equations (GEEs) were used to assess the associations. RESULTS:Infants in the EDB group had the lowest incidence of GI symptoms and lower IGSQ scores throughout the follow-up period. Compared with EDB, the MF group showed higher IGSQ scores (β = 0.95, p = 0.002) and higher odds of constipation (OR = 1.64, p < 0.001), vomiting (OR = 1.70, p < 0.001), and swallowing difficulty (OR = 1.79, p = 0.002); these associations remained robust across multiple sensitivity analyses. The EBB group showed higher odds of certain symptoms in the main analysis, but sensitivity analyses (e.g., time-varying exposure) indicated that these associations were not robust, except for bloating (OR = 1.31, p = 0.042). CONCLUSIONS:The EDB is the optimal strategy for infant gastrointestinal health and should be prioritized. The MF is robustly associated with increased odds of constipation, vomiting, swallowing difficulty, and overall gastrointestinal burden. The EBB may slightly increase the odds of bloating, which can be mitigated by paced feeding and adequate burping.

Early-life nutrition and the gut microbiota interact to shape host health programming. During early-life development, spanning the neonatal period of initial gut colonization through infancy to toddlerhood, the gut microbiota undergoes dynamic succession driven by feeding patterns, host genetic background, environmental exposures, and other intrinsic and extrinsic factors, among which early feeding practices play a particularly prominent role. Among these factors, human milk oligosaccharides (HMOs), key bioactive components of human milk, contribute to the shaping of infant gut microbial ecology by selectively supporting HMO-utilizing bacteria, influencing microbial metabolism and cross-feeding, and exhibiting structure- and context-dependent effects on pathogen-host interactions, intestinal barrier function, and immune responses. This narrative review summarizes the succession patterns of the gut microbiota in early life and the core regulatory mechanisms by which HMOs shape infant gut microbial ecology, aiming to provide a conceptual basis for understanding the potential long-term health implications of early nutritional interventions.

Background:Previous studies have shown that exposure to famine during early life is associated with long-term health outcomes. However, findings on the association between famine exposure and the risk of hypertension remain inconsistent. This study aimed to investigate the relationship between famine exposure at different early-life stages and the incidence of hypertension among Chinese adults, and further evaluate the interaction effect of Dietary Inflammatory Index (DII) on the risk of incident hypertension. Methods:Using data from the China Health and Nutrition Survey (2004-2015), a Chinese population-based cohort, participants were divided into three groups based on their birth year relative to the Great Chinese Famine: the fetal exposure group, the early childhood exposure group, and the non-exposure group. Cox regression was used to assess the association between famine exposure and incident hypertension. To further evaluate the interaction between famine exposure and DII on the risk of incident hypertension, DII was categorized into quartiles and incorporated into the analysis. Results:A total of 603 incident cases of hypertension were identified during the follow-up period. The early childhood exposure group exhibited a significantly higher risk of incident hypertension. Compared with the first DII quartile group, the third quartile group showed a 39% increased risk of incident hypertension. Additionally, a significant interaction was observed between DII and early childhood famine exposure in the fourth quartile group. Conclusions:Early childhood famine exposure showed a significant interaction with the DII, suggesting effect modification in the association between dietary inflammatory potential and adult hypertension. These findings highlight the potential value of targeted nutritional and dietary guidance for Chinese individuals with early-life nutritional adversity.

Introduction:Maternal nutritional status during pregnancy affects pregnancy outcomes and the lifelong health of mothers and offspring. In China, prenatal dietary habits and nutritional supplement usage vary across geographic regions, socioeconomic strata, and dietary cultures. This study aimed to evaluate and compare dietary and nutrient intakes of urban and rural pregnant women in China, providing baseline data for relevant health guidance and strategies. Methods:This multi-stage cross-sectional survey recruited 653 healthy urban and rural pregnant women in their second or third trimesters from 2 municipalities and 11 provinces in China. Dietary and nutritional supplement consumption was assessed using a 4-day online diary paired with a food atlas. The total daily intake of each food category, energy, and key nutrients was evaluated based on the Chinese balanced dietary pagoda and the Chinese Dietary Reference Intakes. The Mann-Whitney U test and Chi-square test were utilized to compare urban-rural differences. Results:In this study, both urban and rural pregnant women in different trimesters exhibited an inadequate consumption of multiple food categories: potatoes, vegetables, fruits, fish, shrimp, and shellfish, eggs, milk and its products, soybeans and its products, and nuts, while the intake of livestock meat and poultry, and cooking oil were excessive. Energy and protein intake were inadequate, with imbalanced energy contributions of carbohydrates and fats. Micronutrient deficiencies were widespread, with 13.5 ~ 99.2% of individuals falling below their estimated average references, particularly for VA, VB1, VB6, VB9, calcium, magnesium, and iodine. These nutritional challenges were more severe in rural areas than in urban areas. Discussion:In conclusion, dietary intake of both urban and rural pregnant women in China is highly imbalanced. Even with nutritional supplements in the survey, many pregnant women lack essential nutrients. A scientific nutrition plan should be developed for them, and a diverse and balanced diet is crucial, especially in rural areas.

Background: Adequate hydration for preschool children (36-72 months) is critical for their healthy growth, cognitive development, and long-term well-being. However, there is still a lack of reliable baseline data in China to inform water intake guidelines for this age group. Methods: In this study, a cross-sectional analysis was conducted using data from the 2018-2019 Dietary Survey of Infants and Young Children in China, including 676 healthy preschool children. Water and energy intake were estimated using four-day food diaries. Their daily total water intake (TWI) and total energy intake (TEI) were evaluated, and the contributions of beverages and foods to TWI and TEI were analyzed, respectively. The TWI was compared with the adequate intake (AI) set by the Chinese Nutrition Society, and the correlations between water and energy intake were explored. Results: The results show that the median daily TWI was 1218 mL, with 667 mL (55.7%, r = 0.824) from beverages and 520 mL (44.3%, r = 0.691) from foods. Among beverages, plain water (74.4%, r = 0.903) and milk and milk derivatives (MMDs, 20.9%, r = 0.443) were the main contributors, while staple foods, dishes, and soup contributed the majority of the water from foods. Only 19.4% of children's TWI met the AI level, and their water and energy intake was significantly higher than those who did not. The median daily TEI was 994 kcal, with 739 kcal (77.2%, r = 0.806) from foods and 198 kcal (22.8%, r = 0.644) from beverages. MMDs accounted for 83.1% of beverage energy (r = 0.880). Boys consumed more beverages than girls, especially in the 37-48 months group. Conclusions: As the first nationally representative study of TWI among Chinese preschool children, these findings reveal a substantial gap between actual intake and current recommendations, and highlight the need to revise reference values and improve hydration guidance in early childhood.

IntroductionDairy products are an important source of high-quality protein, calcium, vitamin A, and other nutrients, and they are a crucial part of a balanced diet for children. However, the daily intake of dairy products among school-age children in China is significantly inadequate. Considering school lunches as a vital pathway for children to obtain nutrients, this study aims to develop school lunch dishes incorporating mozzarella cheese and to assess the acceptance of these dishes among school-age children.MethodsThis study was carried out in a primary school which has a self-run canteen in Nanjing. We innovatively integrated cheese with traditional Chinese food, and conducted a 3-month pilot study to develop dishes that meet the nutritional needs and sensory experience of students. 121 students with an average age of 9.8 years were invited to assess each dishes’ appearance, aroma, taste and overall liking, by using a 5-point Likert Scale. Focus group discussions were conducted after the project to further discover students’ attitude toward cheese dishes and canteen cooks’ experience in improving cheese dishes.ResultsDuring the program, 16 cheese dishes were made, including 3 steamed dishes, 2 ready-to-eat foods (only heating required), and 11 stir-fried dishes. The overall liking’ results showed that ready-to-eat foods were the most popular among students, and steamed dishes ranked higher than stir-fried dishes (P < 0.001). Among the stir-fried dishes, students’ liking scores differed for cheese dishes made from different raw materials, pure meat food was more popular than vegetable food (P = 0.003), meat and vegetable food (P = 0.012). Additionally, focus group discussions found that students gave more positive ratings to and ready-to-eat foods and steamed dishes.ConclusionCheese can be well combined with traditional Chinese ingredients and be accepted, especially steamed or combined with meat. Introducing cheese in school lunches not only helps cultivate a habit of consuming cheese among children and adolescents from a young age, but also aids in closing the gap between their dairy consumption and dietary guidelines.

Background: Over the past several decades, the prevalence of gestational diabetes mellitus (GDM) has risen markedly worldwide, posing serious threats to both maternal and child health by increasing adverse pregnancy outcomes and long-term metabolic risks. Developing effective risk prediction tools for early detection and intervention has become the most important clinical priority in this field. The current GDM prediction models primarily rely on non-modifiable factors, for example age and body mass index, while modifiable factors such as lifestyle and health literacy, although strongly associated with GDM, have not been fully utilized in risk assessment. This study sought to establish and validate a nomogram prediction model combining modifiable and non-modifiable risk factors, with the goal of identifying high-risk Chinese pregnant women with GDM at an early stage and promoting targeted prevention and personalized prenatal management. Methods: A multicenter study was conducted across 7 maternal health institutions in Southern China (2021-2023), enrolling 806 singleton pregnant women (14-23+6 weeks). The collected data included sociodemographic, clinical history, and modifiable factors collected through validated questionnaires: dietary quality, physical activity level, sleep quality, and nutrition and health literacy. GDM was diagnosed via 75 g oral glucose tolerance test at 24-28 weeks. Predictive factors were identified through multi-variable logistic regression. A nomogram model was developed (70% modeling group) and validated (30% validation group). Receiver operator characteristic curves, calibration curves, and decision curve analysis were used to evaluate the prediction ability, the degree of calibration, and the clinical benefit of the model, respectively. Results: The finalized risk prediction model included non-modifiable factors such as maternal age, pre-pregnancy weight, and maternal polycystic ovary syndrome, as well as modifiable factors including dietary quality, physical activity level, sleep quality, nutrition and health literacy. The application of the nomogram in the modeling group and the validation groups showed that the model had high stability, favorable predictive ability, good calibration effect and clinical practicality. Conclusions: Overall, the integrated model demonstrates significant clinical utility as it facilitates the prompt identification of individuals at heightened risk and offers actionable targets for personalized interventions. In terms of future implementation, this model can be integrated into prenatal care as a rapid scoring table during early pregnancy consultations or incorporated into mobile health applications. This approach fosters precise prevention strategies for GDM in maternal health by emphasizing nutrition and health literacy, supplemented by coordinated adjustments in diet, physical activity, and sleep.

Polyamines in human milk are essential for the rapid growth and development of neonates and infants. However, the concentrations of polyamines in human milk have not been well characterized and the special methods for detecting polyamines in human milk, formula milk, or other dairy products remain largely unavailable to date. In this study, an accurate and sensitive method based on trifluoroacetic acid anhydride (TFAA) derivatization, double solid-phase extraction (SPE) purification, and gas chromatography-triple quadrupole mass spectrometry (GC-QqQ MS) was established for the evaluation of polyamines in human milk, formula milk, and other dairy products. High coefficients of determination for internal calibration curves were obtained (R2 > 0.99). Low limits of detection (5.0, 1.0, and 0.5 nmol/dL) and limits of quantification (10.0, 3.0, and 1.0 nmol/dL) for putrescine, spermidine, and spermine, respectively, were also achieved. The precision (expressed as relative standard deviation, RSD < 9.0%) and recovery rates (78.3-108.4%) were satisfactory. Spermidine and spermine in human milk were found significantly higher than those in formula milk and commercial cow's milk. The difference of polyamine content in human milk and infant formula should be paid attention to, particularly when infant formula is used as a complete replacement for human milk.

Breastfeeding is widely recognized as the gold standard for infant nutrition, benefitting infants’ gastrointestinal tracts. Stool analysis helps in understanding pediatric gastrointestinal health, but the effectiveness of automated fecal consistency evaluation by parents of breastfeeding infants has not been investigated. Photographs of one-month-old infants’ feces on diapers were taken via a smartphone app and independently categorized by Artificial Intelligence (AI), parents, and researchers. The accuracy of the evaluations of the AI and the parents was assessed and compared. The factors contributing to assessment bias and app user characteristics were also explored. A total of 98 mother–infant pairs contributed 905 fecal images, 94.0% of which were identified as loose feces. AI and standard scores agreed in 95.8% of cases, demonstrating good agreement (intraclass correlation coefficient (ICC) = 0.782, Kendall’s coefficient of concordance W (Kendall’s W) = 0.840, Kendall’s tau = 0.690), whereas only 66.9% of parental scores agreed with standard scores, demonstrating low agreement (ICC = 0.070, Kendall’s W = 0.523, Kendall’s tau = 0.058). The more often a mother had one or more of the following characteristics, unemployment, education level of junior college or below, cesarean section, and risk for postpartum depression (PPD), the more her appraisal tended to be inaccurate (p < 0.05). Each point increase in the Edinburgh Postnatal Depression Scale (EPDS) score increased the deviation by 0.023 points (p < 0.05), which was significant only in employed or cesarean section mothers (p < 0.05). An AI-based stool evaluation service has the potential to assist mothers in assessing infant stool consistency by providing an accurate, automated, and objective assessment, thereby helping to monitor and ensure the well-being of infants.

School lunch plays an important role in children's healthy growth. Previous investigations revealed many problems with school lunches, including unreasonable dietary structure and insufficient micronutrients. This study aimed to assess the dietary structure and nutritional quality of lunches in Nanjing primary and middle schools. A stratified cluster random sampling method was used to select 44 schools that supply lunch in 12 districts in Nanjing, with two primary and two middle schools in each district. Twenty-four primary and twenty middle schools were selected. The Mann-Whitney U test was used to explore the influencing factors. Findings revealed a serious shortage of milk and fruit in school lunches; supply of eggs, fish, shrimp, and shellfish was less than half of the recommended quantity; livestock and poultry supply exceeded the recommended level by over four times. Energy and nutrition intake were suboptimal. Provision of energy, carbohydrates, vitamins (A, B1, B2, and C), calcium, and iron in urban primary schools was significantly higher than that in non-urban primary schools. The same pattern of significantly higher nutrients was equally seen in urban middle schools compared with non-urban middle schools, indicating that food supply was affected by regional economies. Therefore, it is urgent to improve the quality of lunches, with a particular focus on those in non-urban areas.

Breastfeeding and human milk are the gold standard for infant feeding. Studying human milk with a systems biology approach in a large longitudinal cohort is needed to understand its complexity and health implications. The Phoenix study is a multicenter cohort study focusing on the interactions of maternal characteristics, human milk composition, infant feeding practices, and health outcomes of Chinese mothers and infants. A total of 779 mother–infant dyads were recruited from November 2021 to September 2022, and 769 mother–infant dyads were enrolled in the study. Scheduled home visits took place at 1, 4, 6, and 12 months postpartum, and 696 dyads (90.5% participants) completed the 12-month visit. At each visit, maternal and infant anthropometry was assessed. Questionnaires were administered to collect longitudinal information on maternal characteristics and lifestyle, infant feeding, and health. Digital diaries were used to record maternal dietary intake, infant feeding, and stool character. Human milk, maternal feces, infant feces, and infant saliva were collected. An external pharmaceutical-level quality assurance approach was implied to ensure the trial quality. Multi-omics techniques (including glycomics, lipidomics, proteomics, and microbiomics) and machine learning algorithms were integrated into the sample and data analysis. The protocol design of the Phoenix study provides a framework for prospective cohort studies of mother–infant dyads and will provide insights into the complex dynamics of human milk and its interplay with maternal and infant health outcomes in the Chinese population.

Objective: Postpartum depression (PPD) is a common complication after childbirth. Weight misperception can lead to self-esteem issues and mental health problems, especially in women and adolescents. The aim of this study was to investigate the association between weight perception before and during pregnancy and the status of PPD in Southern China. Methods: From October 2021 to November 2023, a multi-stage sampling method was used to recruit 2169 eligible mothers aged 18–49 who had delivered live-born singleton infants within 3 to 180 days postpartum. Anthropometric measurements and face-to-face questionnaire surveys were conducted to collect data. The Kappa test was used to assess the agreement between actual and perceived weight. The generalized linear model incorporating multiplicative interaction analysis was applied to explore the associations among variables. Results: The prevalence of PPD status was 18.0%. Among women, 35.2% perceived their pre-pregnancy weight (PPW) as abnormal, while 33.1% perceived their gestational weight gain (GWG) as inappropriate. There was poor agreement between maternal actual and perceived PPW/GWG (Kappa = 0.366, p < 0.001; Kappa = 0.188, p < 0.001), with 27.8% of women misperceiving their PPW and 52.1% misperceiving their GWG. The results of the general linear model indicated that women who perceived their PPW as underweight (β = 0.70, p = 0.016) or overweight/obese (β = 0.86, p < 0.001), as well as those who perceived their GWG as excessive (β = 0.47, p = 0.028) were more likely to exhibit PPD status. The interaction analysis results showed that those who perceived their PPW as underweight and their GWG as insufficient (β = 1.75, p = 0.020), as well as those who perceived their PPW as overweight/obese and their GWG as excessive (β = 0.90, p = 0.001) had a positive interactive effect on the occurrence of PPD status, while underestimating PPW and GWG may be a protective factor against PPD status (β = −1.03, p = 0.037). Conclusion: These findings support that maternal weight perception plays a role in the development of PPD status. Further improvement is needed in personalized health education for weight management, both prior to and throughout the pregnancy period. This can help women reduce weight anxiety, better understand their body image, and potentially lower the risk of developing PPD.

Background: the relationship between vitamin D deficiency and carotid intima-media thickness (CIMT) in children and adolescents with obesity is unknown. The aim of this study was to investigate the correlation between vitamin D levels and CIMT in children and adolescents with obesity. Methods: a total of 440 children and adolescents aged 6-16 with obesity were included in the study. Anthropometric measurements, blood pressure measurements, blood lipids, blood glucose, and vitamin D levels were measured. Bilateral carotid ultrasound was performed to assess CIMT. The relationships between vitamin D levels and CIMT were assessed using multivariate linear regression with Generalized Linear Models and restricted cubic splines. Binary logistic regression analyses were conducted to explore the association between vitamin D status and the risk of abnormal CIMT. Results: vitamin D levels were inversely correlated with CIMT in subjects with serum 25-hydroxyvitamin D [25(OH)D] levels less than or equal to 50 nmol/L (ss =-0.147, 95 % CI [-0.263,-0.030], p = 0.013), but this correlation was not significant in subjects with serum 25(OH)D levels above 50 nmol/L. After correcting for various confounders, the risk of abnormal CIMT was significantly higher in the vitamin D deficiency group (OR = 2.080, 95 % CI [1.112, 3.891], p = 0.022). Conclusions: vitamin D deficiency is an independent risk factor for abnormal CIMT, and vitamin D deficiency may play a promoting role in the atherosclerotic process in children and adolescents with obesity.

Toddlerhood (aged 13~36 months) is a period of dietary transition, with water intake being significantly influenced by parental feeding patterns, cultural traditions, and the availability of beverages and food. Nevertheless, given the lack of applicable data, it is challenging to guide and evaluate the water intake of toddlers in China. In this study, our objectives were to assess the daily total water intake (TWI), evaluate the consumption patterns of various beverages and food sources contributing to the TWI, determine the conformity of participants to the adequate intake (AI) recommendation of water released by the Chinese Nutrition Society, and analyze the various contributors to the daily total energy intake (TEI). The data for the assessment of water and dietary intake were obtained from the cross-sectional dietary intake survey of infants and young children (DSIYC, 2018–2019). A total of 1360 eligible toddlers were recruited in the analysis. The differences in related variables between two age groups were compared by Mann–Whitney U test and Chi-Square test. The potential correlation between water and energy intake was examined utilizing age-adjusted partial correlation. Toddlers consumed a median daily TWI of 1079 mL, with 670 mL (62.3%, r = 0.752) derived from beverages and 393 mL (37.7%, r = 0.716) from foods. Plain water was the primary beverage source, contributing 300 mL (52.2%, r = 0.823), followed by milk and milk derivatives (MMDs) at 291 mL (45.6%, r = 0.595). Notably, only 28.4% of toddlers managed to reach the recommended AI value. Among these, toddlers obtain more water from beverages than from foods. The median daily TEI of toddlers was 762 kcal, including 272 kcal from beverages (36.4%, r = 0.534) and 492 kcal from foods (63.6%, r = 0.894). Among these, the median daily energy intake from MMDs was 260 kcal, making up 94.6% of the energy intake from beverages (r = 0.959). As the pioneer survey on TWI of toddlers in China based on nationally representative data, attention to the quality and quantity of water intake and actions to better guide parents by both individuals and authorities are eagerly anticipated. Additionally, the revision of the reference value of TWI for Chinese toddlers is urgently required.

Introduction The coronavirus disease 2019 (COVID-19) pandemic triggered a global public health crisis and has brought an unprecedented impact on pregnant women. The problems faced by pregnant women in the rural areas of China during the epidemic are different from those in urban areas. Although the epidemic situation in China has gradually improved, studying the impact of the previous dynamic zero COVID-19 policy on the anxiety status and lifestyle of pregnant women in rural areas of China, is still necessary. Methods A cross-sectional survey of pregnant women in rural South China was conducted from September 2021 to June 2022.Using questionnaires, sociodemographic characteristics, anxiety status, physical activity, sleep quality, and dietary status of the population were collected. Using the propensity score matching method, the effect of the dynamic zero COVID-19 strategy on the anxiety status and lifestyle of pregnant women was analyzed. Results Among the pregnant women in the policy group ( n = 136) and the control group ( n = 680), 25.7 and 22.4% had anxiety disorders, 83.1 and 84.7% had low or medium levels of physical activity, and 28.7 and 29.1% had sleep disorders, respectively. However, no significant difference ( p > 0.05) was observed between the two groups. Compared with control group, the intake of fruit in the policy group increased significantly ( p = 0.019), whereas that of aquatic products and eggs decreased significantly ( p = 0.027). Both groups exhibited an unreasonable dietary structure and poor compliance with the Chinese dietary guidelines for pregnant women ( p > 0.05). The proportion of pregnant women in the policy group, whose intake of stable food ( p = 0.002), soybean, and nuts ( p = 0.004) was less than the recommended amount, was significantly higher than that in the control group. Discussion The dynamic zero COVID-19 strategy had little impact on the anxiety status, physical activity, and sleep disorders of pregnant women in the rural areas of South China. However, it affected their intake of certain food groups. Improving corresponding food supply and organized nutritional support should be addressed as a strategic approach to improve the health of pregnant women in rural South China during the pandemic.

The dietary nutritional status of pregnant women is critical for maintaining the health of both mothers and infants. Food exchange systems have been employed in the nutritional guidance of patients in China, although their application in the dietary guidance of healthy pregnant women is quite limited. This study aimed to develop a novel food exchange system for Chinese pregnant women (NFES-CPW) and evaluate the relative validation of its application. NFES-CPW covers approximately 500 types of food from ten categories and has more elaborate food portion sizes. It established a recommendation index for guiding food selection and used energy, water content, and protein as the exchange basis to balance the supply of energy and important nutrients throughout pregnancy. Furthermore, dietitians used the NFES-CPW and traditional food exchange system to generate new recipes based on the sample recipe. There were 40 derived recipes for each of the two food exchange methods. The food consumption, energy, and key nutrients of each recipe were calculated, and the differences between the two food exchange systems were compared using the Wilcoxon rank sum test or the Chi-square test. The results revealed that compared to those derived from traditional food exchange system, the NFES-CPW derived recipes had a better dietary structure, as evidenced by the intakes of whole-grain cereals, beans excluding soybeans, potatoes, fruits, fish, shrimp and shellfish, as well as eggs (P < 0.05), which were more conducive to reaching the recommended range of balanced dietary pagoda. After calculating energy and nutrients, although these two food exchange systems have similar effects on the dietary energy and macronutrient intake of pregnant women, the intake of micronutrients in NFES-CPW derived recipes was significantly higher than that from the traditional food exchange system, which was more conducive to meeting the dietary requirements of pregnant women. The outstanding improvement are primarily vitamin A, vitamin B2, folic acid, vitamin B12, vitamin C, calcium, iron, and iodine (P < 0.05). Moreover, when compared to recipes obtained from the traditional food exchange system, the error ranges of energy and most nutrients were significantly reduced after employing the NFES-CPW. Therefore, NFES-CPW is an appropriate tool that adheres to Chinese dietary characteristics and can provide suitable dietary guidance to pregnant women.

Adequate water intake and optimal hydration status during pregnancy are crucial for maternal and infant health. However, research on water intake by pregnant women in China is very limited. This study mainly aimed to observe the daily total water intake (TWI) of pregnant women and its different sources and to investigate the relationship between their water intake and hydration biomarkers. From October to November 2020, a convenience sample of pregnant women in the second trimester (n = 21) was recruited. Under conditions close to daily life, they undertook a 3-day metabolic trial. Each participant was provided with sufficient bottled water, and the weight of what they drank each time was measured. The intake of other beverages and foods was measured using a combination of weighing and duplicate portion method. Fasting venous blood and 24 h urine samples were collected and analyzed for the hydration biomarkers, including the serum/urine osmolality, urine pH, urine specific gravity, and the concentrations of major electrolytes in urine and serum. The results showed that the mean daily TWI was 3151 mL, of which water from beverages and foods accounted for 60.1% and 39.9%, respectively. The mean total fluid intake (TFI) was 1970 mL, with plain water being the primary contributor (68.7%, r = 0.896). Among the participants, 66.7% (n = 14, Group 1) met the TWI recommendation set by the Chinese Nutrition Society. Further analysis revealed that the TFI, water from beverages and foods, plain water, and milk and milk derivatives (MMDs) were significantly higher in Group 1 than those who did not reach the adequate intake value (Group 2) (p < 0.05). The results of hydration biomarkers showed that the mean 24 h urine volume in Group 1 was significantly higher than that in Group 2 (p < 0.05), while the 24 h urine osmolality, sodium, magnesium, phosphorus, chloride, and creatinine concentrations in Group 1 were significantly lower than those in Group 2 (p < 0.05). However, no significant differences were observed in serum biomarkers. Partial correlation analysis showed that TWI was moderately positively correlated with 24 h urine volume (r = 0.675) and negatively correlated with urine osmolality, sodium, potassium, magnesium, calcium, phosphorus, and chloride concentrations (r = from−0.505 to −0.769), but it was not significantly correlated with serum biomarkers. Therefore, under free-living conditions, increasing the daily intake of plain water and MMDs is beneficial for pregnant women to maintain optimal hydration. The hydration biomarkers in urine are more accurate indicators of water intake and exhibit greater sensitivity compared to serum biomarkers. These findings provide a scientific basis for establishing appropriate water intake and hydration status for pregnant women in China.