The Association Between Pre-pregnancy BMI and Preterm Delivery in a Diverse Southern California Population of Working Women

Whereas preterm birth has consistently been associated with low maternal pre-pregnancy weight, the relationship with high pre-pregnancy weight has been inconsistent. We quantified the pre-pregnancy BMI—preterm delivery (PTD) relationship using traditional BMI categories (underweight, normal weight, overweight and obese) as well as continuous BMI. Eligible women participated in California’s statewide prenatal screening program, worked during pregnancy, and delivered a live singleton birth in Southern California in 2002–2003. The final analytic sample included 354 cases delivering at <37 weeks, as identified by clinical estimate of gestational age from screening records, and 710 term normal-birthweight controls. Multivariable logistic regression models using categorical BMI levels and continuous BMI were compared. In categorical analyses, PTD was significantly associated with pre-pregnancy underweight only. Nonparametric local regression revealed a V-shaped relationship between continuous BMI and PTD, with minimum risk at the high end of normal, around 24 kg/m². The odds ratio (OR) for PTD associated with low BMI within the normal range (19 kg/m²) was 2.84 (95%CI = 1.61–5.01); ORs for higher BMI in the overweight (29 kg/m²) and obese (34 kg/m²) ranges were 1.42 (95%CI = 1.10–1.84) and 2.01 (95% CI = 1.20–3.39) respectively, relative to 24 kg/m²). BMI categories obscured the preterm delivery risk associated with low-normal, overweight, and obese BMI. We found that higher BMI up to around 24 kg/m² is increasingly protective of preterm delivery, beyond which a higher body mass index becomes detrimental. Current NHLBI/WHO BMI categories may be inadequate for identifying women at higher risk for PTD.     

Prevalence of Overweight and Obesity Among Women of Childbearing Age: Results from the 2002 National Survey of Family Growth

Objective To estimate the prevalence of overweight and obesity among U.S. women of childbearing age. Methods Our study population was drawn from the 2002 National Survey of Family Growth (NSFG) and consisted of non-pregnant female respondents aged 20–44 years with a valid body mass index (BMI) (N = 5,958). Univariate and bivariate analyses were conducted to document variations in the prevalence of overweight and obesity by age, race and Hispanic origin, and socioeconomic status. Results Overall, 24.5% of women 20–44 years of age were overweight (BMI 25.0–29.9 kg/m²) and 23.0% were obese (BMI ≥ 30.0 kg/m²). Among those who were obese, 10.3% met the criteria for class II or III obesity (BMI ≥ 35.0 kg/m²). Non-Hispanic black and women were 2.25 times more likely to be overweight or obese compared to non-Hispanic white women (95% CI: 1.87–2.69). This disparity in risk between non-Hispanic black and non-Hispanic white women declined and no longer achieved statistical significance after adjustment for education, household income, and health insurance coverage. Conclusions Nearly one in two U.S. women of childbearing age are either overweight or obese. The racial/ethnic disparity in prevalence rates may be due in part to variability in educational attainment, household income, and stability of health insurance coverage.     

Association Between Gestational Weight Gain According to Body Mass Index and Postpartum Weight in a Large Cohort of Danish Women

Our aim was to investigate the association between gestational weight gain (GWG) and postpartum weight retention (PWR) in pre-pregnancy underweight, normal weight, overweight or obese women, with emphasis on the American Institute of Medicine (IOM) recommendations. We performed secondary analyses on data based on questionnaires from 1,898 women from the “Smoke-free Newborn Study” conducted 1996–1999 at Hvidovre Hospital, Denmark. Relationship between GWG and PWR was examined according to BMI as a continuous variable and in four groups. Association between PWR and GWG according to IOM recommendations was tested by linear regression analysis and the association between PWR ≥ 5 kg (11 lbs) and GWG by logistic regression analysis. Mean GWG and mean PWR were constant for all BMI units until 26–27 kg/m². After this cut-off mean GWG and mean PWR decreased with increasing BMI. Nearly 40% of normal weight, 60% of overweight and 50% of obese women gained more than recommended during pregnancy. For normal weight and overweight women with GWG above recommendations the OR of gaining ≥ 5 kg (11 lbs) 1-year postpartum was 2.8 (95% CI 2.0–4.0) and 2.8 (95% CI 1.3–6.2, respectively) compared to women with GWG within recommendations. GWG above IOM recommendations significantly increases normal weight, overweight and obese women’s risk of retaining weight 1 year after delivery. Health personnel face a challenge in prenatal counseling as 40–60% of these women gain more weight than recommended for their BMI. As GWG is potentially modifiable, our study should be followed by intervention studies focusing on GW.     

Accelerometer profiles of physical activity and inactivity in normal weight,overweight, and obese U.S. men and women

Background  

The 2005-2006 National Health and Nutrition Examination Survey (NHANES) is used to describe an accelerometer-derived physical activity/inactivity profile in normal weight (BMI < 25 kg/m²), overweight (25 ≤ BMI < 30 kg/m²), and obese (BMI ≥ 30 kg/m²) U.S. adults.     

Healthcare utilization of overweight and obese Europeans aged 50–79 years

To examine the association between overweight/obesity and healthcare utilization in middle-aged and aged Europeans. This is a baseline cross-sectional analysis of self-reported data from ten countries participating in the Survey of Health, Ageing and Retirement in Europe (SHARE), which reached an overall response rate of 62%. Included in the study were 16,695 non-institutionalized individuals aged 50–79 years with body mass indexes (BMI) ≥18.5 kg/m². We used height and weight to compute BMI and categorized it into normal weight (BMI 18.5–24.9 kg/m²), overweight (BMI 25.0–29.9 kg/m²) and obesity (BMI ≥ 30 kg/m²). Dichotomous measures of healthcare utilization during the previous 12 months included any use of ambulatory care, high use of a general practitioner, visits to specialists, high use of medication, hospitalization, high number of times hospitalized and nights spent in the hospital, surgery, home healthcare and domestic help. Logistic regressions adjusted for age, socio-economic status, smoking, physical activity, alcohol consumption, country of residence, and chronic conditions. All analyses were stratified by gender. Among men and women, being overweight or obese was associated with a significantly increased risk of using ambulatory care and visiting general practitioners, as well as taking ≥2 medication categories. Those relationships were only partially explained by chronic conditions. Obese women were at increased risk and overweight men at decreased risk of hospitalization. For men, exploring other hospitalization dimensions did not reveal significant associations, however. Men and women, whether overweight or obese, did not report higher use of specialists, surgery, home healthcare or domestic help. For all outcomes, similar trends were found at the country level. Population-attributable fractions were highest for medication use, both for men (23%) and women (19%). Despite the rising prevalence of obesity and aging of the population, findings from SHARE show that overweight and obesity place a moderate burden on European healthcare systems, mostly by increasing ambulatory care and medication use.     

Correlation between diet and gut bacteria in a population of young adults

Dietary habits strongly influence gut microbiota. The aim of this study was to compare and correlated the abundance of Firmicutes and Bacteroidetes phyla, some representative bacteria of these phyla such as Bacteroides thetaiotaomicron, Prevotella, Faecalibacterium prausnitzii, Clostridium leptum and Bifidobacterium longum as a member of Actinobacteria phylum in young adults with their food intake. Faecal samples used came from lean subjects (BMI?=?19.83?±?0.94?kg/m²), overweight (BMI?=?27.17?±?0.51?kg/m²) and obese (BMI?=?41.33?±?5.25?kg/m²). There were significant differences in total studied gut microbiota between the overweight and lean groups. Members of the Firmicutes phylum, and Bifidobacterium longum, were more abundant in the lean group. The results suggest that diet rich in unsaturated fatty acids and fibre promote an abundant population of beneficial bacteria such as B. longum and Bacteroidetes. However, it has been considered that the results may be biased due to the size of the individuals studied; therefore the results could be only valid for the studied population.     

Maternal Obesity in Twin Pregnancy: The Role of Nutrition to Reduce Maternal and Fetal Complications

There are more and more obese mothers with twin gestations. For a long time before, the responses of lymphocytes and platelets in obese women can cause a low-grade inflammation. In addition, a proper control of gestational weight gain would improve the outcomes in mothers with high pre-gestational body mass index (BMI). In women with high pre-gestational BMI and twin pregnancy, our aims were to explore the biochemical and hematological parameters and to study the rate of obstetric adverse outcomes. This was an observational and retrospective study conducted in the Hospital Universitario La Paz (Madrid, Spain). We included 20 twin pregnancies as the lean group (BMI = 18.5–24.9 kg/m²), homogeneous in the maternal age and ethnicity, and having parity with other 20 twin pregnancies as the obese group (BMI ≥ 30 kg/m²). The maternal data and maternal, fetal, obstetric, and neonatal complications were collected from the medical records. In the first and third trimester of pregnancy, the biochemical and hematological parameters of the blood were assayed. In this cohort, gestational weight gain was significantly lower in the obese than lean group. In the first trimester, the hemoglobin levels in obese women (12.1 ± 0.8 g/dL) were lower than lean women (12.6 ± 0.7 g/dL; p-Value = 0.048). In addition, the tendency of glucose levels, TSH levels and platelets was to increase in obese compared to lean women. In the third trimester, the TSH levels were higher in obese (3.30 ± 1.60 mUI/L) than lean women (1.70 ± 1.00 mUI/L; p-Value = 0.009). Furthermore, there was a tendency for levels of platelets and lymphocytes to increase in obese compared to lean women. No significant differences were detected in the rate of maternal, fetal, obstetrical, and neonatal complications between the groups. The hemoglobin, platelets, lymphocytes and TSH levels need further investigation to understand potential subclinical inflammation in obese women. Furthermore, obese women with twin pregnancies should follow-up with a specialist nutritionist, to help them control their gestational weight gain with appropriate dietary measures.     

Impact of body mass index on the relationship between muscle quality and physical function in older women

Objectives

To investigate the impact of body mass index (BMI) (normal weight, overweight, obese) on the relationship between muscle quality (MQ) and physical function in community-dwelling older women.

Design

Cross-sectional study.

Setting

University research laboratory.

Participants

Community-dwelling older women (n = 94, 73.6 ± 5.4 y) stratified by BMI (normal weight: 20.0–24.9 kg/m²; overweight: 25.0–29.9 kg/m²; obese: ≥ 30.0 kg/m²).

Measurements

Body mass index using height and weight, leg extension power via the Nottingham power rig, body composition using dual-energy X-ray absorptiometry, and physical function (6-minute walk, 8-foot up-and-go, 30-second chair stand). Muscle quality was defined as leg power (watts) normalized for lower-body mineral-free lean mass (kg).

Results

Following adjustments for covariates, muscle quality was significantly higher in women of normal BMI compared to overweight (10.0 ± 0.4 vs 8.7 ± 0.4 watts/kg, p = 0.03). Muscle quality was a significant predictor of performance on the 6-minute walk and 8-foot up-and-go in normal and overweight women (all p < 0.05) and performance on the 30-second chair stand in normal and obese women (both p < 0.05). Body mass index did not significantly impact the association between MQ and physical function (all p > 0.05).

Conclusions

Muscle quality varies by BMI, yet the relationship to physical function is not significantly different across BMI groups. The results imply that interventions that increase MQ in older women may improve physical function, regardless of BMI.     

Vascular structure and function in women: relationship with body mass index

BACKGROUND: The purpose of the present study was to compare endothelial function in lean (body mass index [BMI]=18.0-24.9 kg/m2); overweight (BMI=25-29.9 kg/m2); and obese (BMI>30 kg/m2), healthy, eumenorrheic women. METHODS: Eighteen lean, 22 overweight, and 19 obese eumenorrheic middle-aged women were studied. Vascular structure and function were assessed via non-invasive ultrasound imaging of the carotid and brachial arteries. Body composition, blood pressure, fasting blood lipids, glucose, and insulin also were measured. RESULTS: The groups demonstrated significantly (p<0.001) different mean values for total body, lean body, and fat masses. The obese group demonstrated significantly (p<0.05) elevated fasting glucose and insulin levels and lower high-density lipoprotein levels as compared to the lean group. The overweight group also demonstrated elevated fasting glucose levels as compared to the lean group (p<0.05) with no significant difference from the obese group. Only systolic blood pressure differed among the three groups, being elevated in the obese group compared to the lean group (p<0.05). The obese group demonstrated significantly (p<0.05) elevated carotid artery lumen diameter, carotid artery wall cross-sectional area, and brachial artery lumen diameter with significantly (p<0.05) lower flow-mediated dilation as compared to the lean group. The overweight group demonstrated elevated carotid artery wall cross-sectional area and brachial artery lumen diameter as well as lower flow-mediated dilation as compared to the lean group (p<0.05). CONCLUSIONS: The results of this study support the hypothesis that carotid artery wall cross-sectional area is elevated and flow-mediated dilation reduced in overweight and obese eumennorheic women as compared to lean counterparts in relation to BMI classification.     

Asian Americans and Obesity in California: A Protective Effect of Biculturalism

Prior studies comparing US-born and foreign-born Asian Americans have shown that birth in the US conveys greater risk of obesity. Our study investigates whether retention of Asian culture might be protective for obesity despite acculturation to US lifestyle. We classified self-identified Asian American respondents of the California Health Interview Survey as traditional, bicultural, and acculturated using nativity and language proficiency in English and Asian language. We then examined the association of acculturation with overweight/obesity (BMI ≥ 25 kg/m²) in a multivariate regression model. Acculturated respondents had higher adjusted odds of being overweight/obese than bicultural respondents (2.13 [1.40–3.23] for men, 3.28 [2.14–5.04] for women), but bicultural respondents had similar odds of being overweight/obese as traditional respondents (.98 [.69–1.41] for men, .72 [.50–1.05] for women). Among the bicultural, second and first generation respondents were equally likely to be overweight/obese. Biculturalism in Asian Americans as measured by Asian language retention appears protective against obesity. Further research is needed to understand the mechanisms underlying this association.     

Gut Microbiota Profile and Its Association with Clinical Variables and Dietary Intake in Overweight/Obese and Lean Subjects: A Cross-Sectional Study

We aimed to differentiate gut microbiota composition of overweight/obese and lean subjects and to determine its association with clinical variables and dietary intake. A cross-sectional study was performed with 96 overweight/obese subjects and 32 lean subjects. Anthropometric parameters were positively associated with Collinsella aerofaciens, Dorea formicigenerans and Dorea longicatena, which had higher abundance the overweight/obese subjects. Moreover, different genera of Lachnospiraceae were negatively associated with body fat, LDL and total cholesterol. Saturated fatty acids (SFAs) were negatively associated with the genus Intestinimonas, a biomarker of the overweight/obese group, whereas SFAs were positively associated with Roseburia, a biomarker for the lean group. In conclusion, Dorea formicigenerans, Dorea longicatena and Collinsella aerofaciens could be considered obesity biomarkers, Lachnospiraceae is associated with lipid cardiovascular risk factors. SFAs exhibited opposite association profiles with butyrate-producing bacteria depending on the BMI. Thus, the relationship between diet and microbiota opens new tools for the management of obesity.     

GC-MS方法检测超重/肥胖男性青年血清游离脂肪酸代谢谱

目的研究超重/肥胖男性血清脂肪酸水平的变化。方法采用气相色谱质谱联用(GC/MS)方法检测30例超重男性和30例体重正常男性血清16种游离脂肪酸水平。结果超重/肥胖组血清高密度脂蛋白胆固醇(HDL-C)水平显著降低(P<0.05)、甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)水平显著升高(P<0.05),血糖(GLU)水平无显著差异(P>0.05);超重/肥胖组血清游离脂肪酸肉豆蔻酸(C14:0)、棕榈酸(C16:0)、软油酸(C16:1)、硬脂酸(C18:0)、油酸(C18:1)、亚油酸(C18:2)、γ-亚麻酸(γ-C18:3)、α-亚麻酸(C18:3)、二十碳二烯酸(C20:2)、二十碳五烯酸EPA(C20:5)、二十二碳六烯酸DHA(C22:6)、二十四碳酸(C24:0)、水平显著高于正常组(P<0.05);总脂肪酸(TFA)、饱和脂肪酸(SFA)、单不胞和脂肪酸(MUFA)、多不饱和脂肪酸(PUFA)、n-3PUFAs、n-6PUFAs水平均高于正常组(P<0.05),PUFA/TFA超重/肥胖组显著低于正常组。多元统计分析结果也显示C14:0、C16:0、C18:0等SFAs以及n-3PUFA C18:3在PCA模型中超重/肥胖组与正常组的分离起到重要作用。结论肥胖发生早期体内即出现血脂和游离脂肪酸等脂类代谢紊乱,C14:0、C16:0、C18:0和C18:3可作为肥胖血清脂肪酸变化的潜在生物标记物。[营养学报,2013,35(2):137-141]     

Nutritional status and oxidative stress in an elderly Sardinian population

Weight loss and overweight/obesity-frequent consequences of malnutrition-may impair functional status and worsen concomitant morbidities in the elderly, often through changes in oxidative balance. In order to verify the relationships between these factors, a group of elderly people living on the island of Sardinia (Italy) underwent health and nutritional status assessment and oxidative balance evaluation. The elderly subjects had significantly higher d-ROMs test and body mass index (BMI) values than controls (d-ROMs 325.4 ± 66.3 vs. 295.4 vs 58-9 CARR U, p = 0.006; BMI 28.0 ± 4.6 vs. 21.7 ± 1.4 kg/m², p < 0.0001). The risk of malnutrition in the elderly subjects was evaluated with the Mini Nutritional Assessment (MNA), which showed that 32 of the 111 elderly subjects (28.8%) were at risk of malnutrition, of whom 11 (34%) were overweight and 10 (31-2%) obese. Oxidative stress was negatively and significantly correlated with nutritional status. Oxidative stress may precede malnutrition, even in the absence of weight loss. Routine evaluation of nutritional status and oxidative balance in the elderly may help identify an early risk of malnutrition so that treatment can be personalized.     

What is the nutritional status of children of obese mothers in South Africa?

Objective

To evaluate the anthropometric status of children of obese (body mass index [BMI] ≥30 kg/m²) mothers who participated during the 2005 National Food Consumption Study.

Methods

The survey population consisted of children 1-9 y of age and their mothers 16 to 35 y of age living in the same households (n = 1532). A national sample of households was drawn, representative of all nine provinces and urban and rural areas. Trained fieldworkers measured the heights and weights of participants at their homes.

Results

The prevalence of obesity was high in the mothers (27.9%), particularly in the 26- to 35-y-old (older) group (32.3%) and in urban areas (29.1%). Children of older mothers had a significantly (P < 0.05) higher mean height-for-age Z-score (−0.91) than those of younger mothers (16 to 25 y old, −1.06). Mean weight-for-age and weight-for-height Z-scores were significantly higher in children of obese women compared with those of non-obese women (BMI <30 kg/m², P < 0.001). Furthermore, obese mothers had significantly more overweight children than non-obese mothers (P < 0.0001). Eighty-four percent of overweight children also had mothers with a BMI ≥25 kg/m² and 52% had mothers with a BMI ≥30 kg/m²(∗ indicates statistical significance of confidence interval). Stunted mothers had a 1.5 times higher risk of being overweight (BMI ≥25 kg/m², odds ratio 1.45, confidence interval 1.06-2.01).

Conclusion

Overall, children of obese mothers had significantly higher mean Z-scores than those of mothers who were non-obese. Overweight and obese women were significantly less likely to have stunted or underweight children, whereas underweight women and stunted women were significantly more likely to have underweight and stunted children, respectively.     

Association of Body Mass Index with Ischemic and Hemorrhagic Stroke

Data on the association between body mass index (BMI) and stroke are scarce. We aimed to examine the association between BMI and incident stroke (ischemic or hemorrhagic) and to clarify the relationship between underweight, overweight, and obesity and stroke risk stratified by sex. We analyzed the JMDC Claims Database between January 2005 and April 2020 including 2,740,778 healthy individuals (Median (interquartile) age, 45 (38–53) years; 56.2% men; median (interquartile) BMI, 22.3 (20.2–24.8) kg/m²). None of the participants had a history of cardiovascular disease. Each participant was categorized as underweight (BMI <18.5 kg/m²), normal weight (BMI 18.5–24.9 kg/m²), overweight (BMI 25.0–29.9 kg/m²), or obese (BMI ≥ 30 kg/m²). We investigated the association of BMI with incidence stroke in men and women using the Cox regression model. We used restricted cubic spline (RCS) functions to identify the association of BMI as a continuous parameter with incident stroke. The incidence (95% confidence interval) of total stroke, ischemic stroke, and hemorrhagic stroke was 32.5 (32.0–32.9), 28.1 (27.6–28.5), and 5.5 (5.3–5.7) per 10,000 person-years in men, whereas 25.7 (25.1–26.2), 22.5 (22.0–23.0), and 4.0 (3.8–4.2) per 10,000 person-years in women, respectively. Multivariable Cox regression analysis showed that overweight and obesity were associated with a higher incidence of total and ischemic stroke in both men and women. Underweight, overweight, and obesity were associated with a higher hemorrhagic stroke incidence in men, but not in women. Restricted cubic spline showed that the risk of ischemic stroke increased in a BMI dose-dependent manner in both men and women, whereas there was a U-shaped relationship between BMI and the hemorrhagic stroke risk in men. In conclusion, overweight and obesity were associated with a greater incidence of stroke and ischemic stroke in both men and women. Furthermore, underweight, overweight, and obesity were associated with a higher hemorrhagic stroke risk in men. Our results would help in the risk stratification of future stroke based on BMI.     

Association between the Erythrocyte Membrane Fatty Acid Profile and Cognitive Function in the Overweight and Obese Population Aged from 45 to 75 Years Old

Dietary fatty acid intake is closely related to the cognitive function of the overweight and obese population. However, few studies have specified the correlation between exact fatty acids and cognitive functions in different body mass index (BMI) groups. We aimed to explain these relationships and reference guiding principles for the fatty acid intake of the overweight and obese population. Normal weight, overweight, and obese participants were recruited to receive a cognitive function assessment and dietary survey, dietary fatty acids intake was calculated, and the erythrocyte membrane fatty acid profile was tested by performing a gas chromatography analysis. The percentages of saturated fatty acids (SFAs) in the obese group were higher, while monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) were lower than in the normal weight and overweight groups. In the erythrocyte membrane, the increase of n-3 PUFAs was accompanied by cognitive decline in the overweight group, which could be a protective factor for cognitive function in the obese group. High n-6 PUFAs intake could exacerbate the cognitive decline in the obese population. Dietary fatty acid intake had different effects on the cognitive function of overweight and obese people, especially the protective effect of n-3 PUFAs; more precise dietary advice is needed to prevent cognitive impairment.     

Contraceptive choices of overweight and obese women in a publically funded hospital: possible clinical implications

BackgroundDespite the growing obesity epidemic in the United States, family planning for overweight and obese women has been understudied. The aim of this study was to describe the contraception methods selected by normal weight, overweight and obese women.Study DesignWe retrospectively reviewed 7262 charts of women who underwent first trimester surgical termination of pregnancy at the John H. Stroger, Jr. Hospital of Cook County between January 1, 2008, and January 1, 2010. We analyzed the relationship between body mass index (BMI) and choice of contraceptive method, after adjusting for age, race, smoking and level of education.ResultsWhen compared to patients with BMI <25 kg/m², overweight (BMI 25–29.9 kg/m²) and obese patients (BMI ≥30 kg/m²) were more likely to select the intrauterine device (OR 1.3, 95% CI 1.28–1.32 for overweight; OR 1.6, 95% CI 1.59–1.61 for obese), contraceptive ring (OR 1.4, 95% CI 1.28–1.52 for overweight; OR 1.6, 95% CI 1.57–1.63 for obese) and tubal ligation (OR 1.5 95% CI 1.44–1.62 for overweight; OR 2.9, 95% CI 2.79–3.01 for obese). They were less likely to choose injectable contraception (OR 0.7, 95% CI 0.59–0.81 for overweight; OR 0.52, 95% CI 0.48–0.56 for obese). There was no relationship between BMI and choice of condoms, oral contraceptive pills and implantable methods.ConclusionIn our population, the contraceptive choices of overweight and obese women differed from those of normal weight women. These differences in contraceptive selection are important to recognize in light of the potential effect of BMI on the safety and efficacy of different contraceptive methods. Further research is needed to evaluate the contraceptive preferences, risks and benefits for overweight and obese women.     

Health Behaviours during Pregnancy in Women with Very Severe Obesity

The health behaviours of pregnant women with very severe obesity are not known, though these women are at high risk of pregnancy complications. We carried out a prospective case-control study including 148 very severely obese (BMI >40 kg/m²) and 93 lean (BMI <25 kg/m²) pregnant women. Diet, physical activity, smoking, alcohol and folic acid consumption were assessed by questionnaire in early and late (16 and 28 weeks gestation) pregnancy. Circulating levels of iron, vitamin B12 and folate and other essential trace elements and minerals were measured in a subset at each time point. The findings biochemically confirmed that very severely obese women consumed diets that were energy-rich but poor in essential micronutrients. A third of all women met physical activity recommendations for pregnancy. A third of very severely obese women and two thirds of lean women took folic acid supplements prior to pregnancy. Very severely obese women were more likely to smoke but less likely to drink alcohol than lean women (all p < 0.05). Women with very severe obesity have low self-reported intakes and circulating levels of essential micronutrients in pregnancy and few follow current recommendations for pregnancy nutrition and lifestyle. These high-risk women represent a group to target for education about health behaviours prior to and during pregnancy.     

Trends in Energy Imbalance Gap and Body Weight Status in the Japanese Adult Population: A System Dynamics Approach

BackgroundThe double burden of malnutrition is a growing public health problem in Japan. We estimated the dynamics of the energy imbalance gap (EIG) (average daily difference between energy intake and expenditure) to explain trends in the prevalence of underweight, overweight, and obese Japanese adults.MethodsWe used individual-level data on body height and weight from the National Health and Nutrition Surveys from 1975 to 2015. We calibrated a validated system dynamics model to estimate the EIG for Japanese adults aged 20 to 74 years by survey year, sex, and weight status classified by the body mass index (BMI).ResultsThe overall EIG for men increased from 2.3 kcal/day in 1975 to 4.7 kcal/day in 1987 and then decreased to 2.3 kcal/day in 2015. The overall EIG for women consistently decreased from 4.3 kcal/day in 1975 to −0.5 kcal/day in 2015. By BMI class, the EIG for men with a BMI of <30 kg/m² began to decrease around 1990, indicating a deceleration in the prevalence of overweight and obese men. The EIG consistently decreased for women with a BMI of <25 kg/m² and reached negative values from the late 2000s to early 2010s, indicating a gradual decrease in the prevalence of overweight and obese women.ConclusionsThe dynamics of the EIG were different across sex and weight groups. Public health interventions should target a further decrease in the EIG for normal-weight, overweight, and obese men and a stop in the decreasing trends of the EIG in underweight and normal-weight women.Key words: energy balance, underweight, overweight, obesity, systems science     

Population-Based Assessment of the Risk of Primary Cesarean Delivery Due to Excess Prepregnancy Weight Among Nulliparous Women Delivering Term Infants

Objective: To estimate the risk of cesarean delivery due to excess prepregnancy body mass index (BMI) in a multistate, US population-based sample. Methods: We analyzed data from the population-based Pregnancy Risk Assessment Monitoring System (PRAMS) on 24,423 nulliparous women with single, term infants delivered between 1998 and 2000 in 19 states. We calculated BMI from self-reported weight and height. We assessed interactions between prepregnancy BMI and other risk factors. We estimated weighted relative risks and 95% confidence intervals for the association between prepregnancy BMI and cesarean section from multiple logistic regression models adjusting for demographic and medical risk factors from the PRAMS questionnaire or birth certificates. Results: The incidence of cesarean delivery increased with increased prepregnancy BMI, from 14.3% (0.8 standard error (SE)) for lean women (BMI < 19.8) to 42.6% (2.0 SE) for very obese women (BMI ≥ 35). The risk of cesarean section differed by presence of any medical, labor and/or delivery complication. Among women with any complication, the estimated adjusted RR for cesarean delivery was 1.1 (95% confidence interval (CI) 1.0–1.2) among overweight women, 1.3 (95% CI 1.1–1.4) among obese women, and 1.4 (95% CI 1.2–1.6) among very obese women compared with normal weight women. Among women without any complications, the estimated adjusted RR was 1.4 (95% CI 1.0–1.8) among overweight women, 1.5 (95% CI 1.1–2.1) among obese women, and 3.1 (95% CI 2.3–4.8) among very obese women. Conclusion: Excess prepregnancy weight increases the risk of cesarean delivery among nulliparous women giving birth to single, term infants, especially among very obese women without any complications.