Gestational weight gain in adolescents: a comparison to the new Institute of Medicine recommendations.

STUDY OBJECTIVE: To examine the gestational weight gain distributions of healthy adolescents with optimal birth outcomes and compare them to the current 2009 Institute of Medicine (IOM) recommendations. DESIGN: Secondary data analysis to conduct a population-based, cross-sectional study. SETTING: The Central and Finger Lakes regions of New York state (Perinatal Database System). PARTICIPANTS: 6995 adolescents with healthy singleton pregnancies (1996 to 2002). MAIN OUTCOME MEASURES: Percentiles of the gestational weight gain distributions were compared within body mass index (BMI) groups categorized using 2 different classification schemes: adolescent BMI percentiles and adult BMI cut-points. We compared these distributions overall and within racial and age groups. RESULTS: The gestational weight gain distribution does not differ considerably when BMI is classified using adolescent or adult cutoffs. Adolescents have good birth outcomes across a wider gestational weight gain range than recommended by the Institute of Medicine regardless of how pre-pregnancy weight status is categorized. For example, overweight adolescents by adult cutoffs have a range of gestational weight gain from 5.0 kg to 30.0 kg, and overweight adolescents by percentile cutoffs have a range from 5.4 kg to 29.5 kg, whereas the IOM range is 7.5-11.5 kg. Black and young adolescents have a similar distribution to their white and older counterparts. CONCLUSION: Practitioners can safely use the new IOM gestational weight gain ranges to monitor weight gain in pregnant adolescent patients using adult BMI classifications. Future research should examine the range of gestational weight gain in adolescents considering a broader scope of birth and maternal outcomes.

Selecting the right polymer.

Choosing the correct polymer for a medical device requires a comprehensive look at many aspects of performance and economy. This decision-making process is illustrated here with approaches to choosing materials for an injection moulded steam sterilisation tray for surgical instruments and goods.

Changes in traffic crash mortality rates attributed to use of alcohol, or lack of a seat belt, air bag, motorcycle helmet, or bicycle helmet, United States, 1982-2001.

OBJECTIVE: To estimate the contributions of five risk factors to changes in US traffic crash mortality: (1) alcohol use by drivers and pedestrians, (2) not wearing a seat belt, (3) lack of an air bag, (4) not wearing a motorcycle helmet, and (5) not wearing a bicycle helmet. DESIGN: Longitudinal study of deaths; attributable deaths were estimated using data from other studies. SETTING: US traffic crashes in 1982-2001. SUBJECTS: People who died in a crash. MAIN OUTCOME MEASURES: Counts of deaths attributed to each risk factor, change in rates of deaths, and counts of lives saved by changes in risk factor prevalence. RESULTS: There were 858 741 traffic deaths during the 20 year period. Estimated deaths attributed to each factor were: (1) alcohol use, 366 606; (2) not wearing a seat belt, 259 239; (3) lack of an air bag, 31 377; (4) no motorcycle helmet, 12 095; (5) no bicycle helmet, 10 552. Over the 20 years, mortality rates attributed to each risk factor declined: alcohol by 53%; not wearing a seat belt by 49%; lack of an air bag by 17%; no motorcycle helmet by 74%; no bicycle helmet by 39%. There were 153 168 lives saved by decreased drinking and driving, 129 297 by increased use of seat belts, 4305 by increased air bag prevalence, 6475 by increased use of motorcycle helmets, and 239 by increased use of bicycle helmets. CONCLUSIONS: Decreased alcohol use and increased use of seat belts were associated with substantial reductions in crash mortality from 1982 through 2001. Increased presence of air bags, motorcycle helmets, and bicycle helmets were associated with smaller reductions.

Gestational weight gain and postpartum behaviors associated with weight change from early pregnancy to 1 y postpartum.

OBJECTIVES: (1) To describe the relative importance of gestational weight gain, postpartum exercise, food intake and breastfeeding to weight change from early pregnancy to 1 y postpartum; and (2) to identify subgroups of women at greatest risk for major weight gain surrounding childbearing. DESIGN: A prospective cohort study of women who registered for obstetrical care in a hospital and primary care clinic system serving a 10 county area of upstate New York. SUBJECTS: A total of 540 healthy adult women who gave birth to full-term singleton infants. MEASUREMENTS: Sociodemographic characteristics, exercise, food-related behaviors and breastfeeding were assessed using the medical record and a mailed questionnaire. Body weight was measured at prenatal visits and 1 y postpartum. Weight retained and major weight gain (4.55 kg) at 1 y postpartum were the main outcomes. ANALYSIS: Linear and logistic regression analyses were conducted. RESULTS: Women were on average 1.51+/-5.95 kg heavier at 1 y postpartum than they were in early pregnancy. Nearly 25% of women experienced a major weight gain of 4.55 kg or more at 1 y postpartum. Gestational weight gain, exercise frequency, change in food intake and breastfeeding were each significantly related to postpartum weight retention. With the exception of breastfeeding, all of these factors were also associated with major weight gain. Women under 20 y or over 40 y at delivery, and single women retained significantly more weight. Lower income women with gestational weight gains above the Institute of Medicine (IOM) range retained 3.73 kg more than lower income women who gained within the range. They were also 4.7 times more likely to experience major weight gain with childbearing. The impact of exceeding the IOM gestational weight gain guidelines was three times greater in lower income women than it was in higher income women. CONCLUSION: Gestational weight gain, postpartum exercise frequency, and food intake are significantly associated with weight change from early pregnancy to 1 y postpartum and major weight gain with childbearing. Lower income women who gain more weight in pregnancy than the IOM recommends are at high risk for major weight gain with childbearing.

Low family income and food insufficiency in relation to overweight in US children: is there a paradox?

OBJECTIVES: To investigate associations between family income, food insufficiency, and being overweight in US children aged 2 to 7 and 8 to 16 years, to discuss mechanisms that may explain these associations, and to propose design and data requirements for further research that could effectively examine this issue. METHODS: Data from the Third National Health and Nutrition Examination Survey were analyzed. Children were classified as food insufficient if the family respondents reported that their family sometimes or often did not get enough food to eat. The prevalence of overweight was compared by family income category and food sufficiency status within age-, sex-, and race-ethnic-specific groups. Odds ratios for food insufficiency are reported, adjusted for family income and other potential confounding factors. RESULTS: Among older non-Hispanic white children, children in families with low income were significantly more likely to be overweight than children in families with high income. There were no significant differences by family income for younger non-Hispanic white children, non-Hispanic black children, or Mexican American children. After adjusting for confounding variables, there were no differences in overweight by food sufficiency status, except that younger food-insufficient girls were less likely to be overweight, and non-Hispanic white older food-insufficient girls were more likely to be overweight than food-sufficient girls (P<.10). CONCLUSION: Further research to evaluate whether food insecurity causes overweight in American children requires longitudinal quantitative and in-depth qualitative methods.

Food insufficiency and American school-aged children's cognitive, academic, and psychosocial development.

OBJECTIVE: This study investigates associations between food insufficiency and cognitive, academic, and psychosocial outcomes for US children and teenagers ages 6 to 11 and 12 to 16 years. METHODS: Data from the Third National Health and Nutrition Examination Survey (NHANES III) were analyzed. Children were classified as food-insufficient if the family respondent reported that his or her family sometimes or often did not get enough food to eat. Regression analyses were conducted to test for associations between food insufficiency and cognitive, academic, and psychosocial measures in general and then within lower-risk and higher-risk groups. Regression coefficients and odds ratios for food insufficiency are reported, adjusted for poverty status and other potential confounding factors. RESULTS: After adjusting for confounding variables, 6- to 11-year-old food-insufficient children had significantly lower arithmetic scores and were more likely to have repeated a grade, have seen a psychologist, and have had difficulty getting along with other children. Food-insufficient teenagers were more likely to have seen a psychologist, have been suspended from school, and have had difficulty getting along with other children. Further analyses divided children into lower-risk and higher-risk groups. The associations between food insufficiency and children's outcomes varied by level of risk. CONCLUSIONS: The results demonstrate that negative academic and psychosocial outcomes are associated with family-level food insufficiency and provide support for public health efforts to increase the food security of American families.

Characteristics of meta-analyses related to acceptance for publication in a medical journal.

Editors of medical journals select manuscripts for publication based, in part, on the perceived quality of the manuscript submitted. The objective of this study was to describe associations between acceptance for publication and quality-related methodologic characteristics of meta-analyses. This was a prospective observational study. The setting was editorial offices of JAMA and offices of external reviewers. The manuscripts reviewed were 112 consecutive meta-analyses submitted to JAMA during 1996 and 1997 whose authors agreed to participate. The main outcome measures were ratings of 16 methodologic characteristics reflecting quality of the meta-analysis and acceptance for publication. A "high" rating for one methodologic characteristic, whether the report of the meta-analysis provided sufficient detail to enable replication, was related significantly to publication (RR = 2.79, 95% CI = 1.13-6.89). This relationship persisted when other variables were controlled for in the model. Generally, rejected manuscripts had fewer factors rated "high," but differences were not significant. We found that inclusion of sufficient detail to allow a reader to replicate meta-analytic methods was the only characteristic related to acceptance for publication.

Food insufficiency, family income, and health in US preschool and school-aged children.

OBJECTIVES: This study investigated associations between family income, food insufficiency, and health among US preschool and school-aged children. METHODS: Data from the third National Health and Nutrition Examination Survey were analyzed. Children were classified as food insufficient if the family respondent reported that the family sometimes or often did not get enough food to eat. Regression analyses were conducted with health measures as the outcome variables. Prevalence rates of health variables were compared by family income category, with control for age and gender. Odds ratios for food insufficiency were calculated with control for family income and other potential confounding factors. RESULTS: Low-income children had a higher prevalence of poor/fair health status and iron deficiency than high-income children. After confounding factors, including poverty status, had been controlled, food-insufficient children were significantly more likely to have poorer health status and to experience more frequent stomachaches and headaches than food-sufficient children; preschool food-insufficient children had more frequent colds. CONCLUSIONS: Food insufficiency and low family income are health concerns for US preschool and school-aged children.

Predictors of pregnancy-associated change in physical activity in a rural white population.

OBJECTIVE: The objective of this study was to examine the relationship of sociodemographic and psychosocial characteristics and exercise prior to pregnancy to change in physical activity (PA) during pregnancy. METHODS: This study was part of the Bassett Mothers' Health Project (BMHP), a prospective cohort study of women who enrolled for prenatal care in the Bassett Healthcare system between November 7, 1994, and November 15, 1996. Six hundred twenty-two women met the eligibility criteria and were enrolled in the study. Sociodemographic and psychosocial characteristics and exercise behavior were assessed prenatally using the medical record and an anonymous mailed questionnaire. Staged linear regression analysis was used to predict change in physical activity with the psychosocial and sociodemographic characteristics as the independent variables and prepregnancy exercise frequency as a control variable. RESULTS: Women who were older, more educated, and had higher household incomes were more likely to exercise prior to pregnancy (p < .05). Change in PA after becoming pregnant was associated with prepregnancy exercise frequency (p < .001). Women who exercised frequently moderated their activity, while sedentary women maintained or increased their PA after becoming pregnant. Exercise self-efficacy (the belief in one's ability to exercise regularly) and body mass index (BMI) were positive predictors of change in PA (p < .05), while prepregnancy exercise frequency remained significant as a control variable. CONCLUSION: Interventions that aim to help women maintain or increase their PA during the perinatal period should be designed to increase exercise self-efficacy.

Evaluation of psychosocial measures for understanding weight-related behaviors in pregnant women.

The greatest weight gain for US. women occurs during the childbearing years of 25 to 34, and many obese women attribute their adult weight gain to childbearing. Few studies have examined psychosocial influences on women's behaviors during pregnancy, in part because of the lack of valid and reliable measures of psychosocial constructs relevant to pregnant women. Based on existing theory and an in-depth interview study, the psychosocial constructs of locus of control, self-efficacy, body image, feelings about motherhood, and career orientation were identified. Scales for each construct were constructed by drawing items from existing validated scales and writing items based on the in-depth interviews; their content validity assessed using factor analysis with oblique rotation and their reliability using Cronbach's alpha. Construct validity was assessed by examining the associations between scale scores and preexisting conditions of participants. Data for evaluating the scales came from a study of 622 pregnant women in a rural health care system who completed questionnaires and whose medical records were audited. Cronbach's alpha of the scales ranged from 0.73 to 0.89. Scale scores were strongly associated with lifestyle behaviors, body weight, and demographic characteristics of the participants. The analysis provides evidence of the validity of measures of psychosocial factors related to health behaviors of pregnant women. These measures should be useful in studying weight-related behaviors in pregnant women.

Postpartum exercise and food intake: the importance of behavior-specific self-efficacy.

OBJECTIVE: To examine the relationships between psychosocial characteristics and change in exercise and food intake of women during the first year postpartum. DESIGN: A prospective cohort study following women from pregnancy until 1 year postpartum. Psychosocial variables, change in food intake, and exercise frequency were assessed using anonymous mailed questionnaires during pregnancy and at 1 year postpartum. Sociodemographic and anthropometric information was obtained from the medical record. SUBJECTS/SETTING: Six hundred twenty-two women who enrolled for prenatal care in the Bassett Healthcare system between November 7, 1994, and November 15, 1996, and who met the eligibility criteria. The attrition rate for completing the questionnaire at 1 year postpartum was 20%. STATISTICAL ANALYSES PERFORMED: Multivariate linear regression with exercise frequency at 1 year postpartum and change in food intake during the second 6 months postpartum as the dependent variables and psychosocial factors assessed at 1 year postpartum as the independent variables, controlling for sociodemographic variables, body mass index, and gestational weight gain. RESULTS: Higher exercise self-efficacy and having the intention to exercise were associated with more frequent exercise at 1 year postpartum in the multivariate regression analysis (r2 = 20%). Food intake self-efficacy, body satisfaction, weight gain acceptance, and drive for thinness were all significant in the multivariate analysis (r2 = 7%) and higher scores on these variables were associated with reductions in food intake. APPLICATIONS/CONCLUSIONS: Interventions that aim to help women get regular exercise and make appropriate reductions in food intake during the postpartum period should focus on self-efficacy specific to the targeted behaviors. For example, dietitians may strengthen exercise self-efficacy by providing postpartum women with mastery experiences of setting realistic exercise goals. Likewise, dietitians can focus on food intake self-efficacy by modeling strategies that women can use to avoid overeating in stressful situations.

New concepts for nutrition education in an era of welfare reform.

In response to welfare reform and the Food Stamp Nutrition Education Program's (FSNEP) goal of increasing clients' self-sufficiency, a literature review and small exploratory study were conducted to gain insight into a potential approach that would go beyond current nutrition education methods. Interviews with 17 FSNEP participants showed a widespread willingness to share food-related skills that others wanted to learn, some interest in cooperating on food-related projects, and frequent cases of social and geographic isolation. Based on these preliminary findings, we suggest the development and evaluation of nutrition education programs that appreciate and build on existing abilities of participants, provide opportunities for self-directed learning and activities, and build social support, social networks, and trust among participants while linking them to the broader community.

Continuity and change in women's weight orientations and lifestyle practices through pregnancy and the postpartum period: the influence of life course trajectories and transitional events.

The life course perspective offers a framework for understanding continuity and change in health and health practices. Body weight, and the diet and physical activity strategies used to manage weight in pregnancy and the postpartum period, are a focus of much study because of an association between parity and body weight. The motherhood transition offers an opportunity to study weight concerns and weight management strategies during a period of weight fluctuation that is part of a life transition for many women. Our aim was to develop an in-depth understanding of women's experiences of pregnancy and postpartum weight changes, the strategies that women used to deal with weight changes, and patterns in their attitudes and strategies across pregnancy and the postpartum period. A longitudinal design, using multiple, in-depth, qualitative interviews with 36 women from pregnancy through the postpartum period, was chosen for data collection. Prepregnancy orientations towards body weight emerged as the primary influence on women's pregnancy and postpartum attitudes towards weight, on patterns of physical activity and diet, and on postpartum weight outcomes among most study participants. Four different trajectories ("relaxed maintenance", "exercise", "determined", and "unhurried"), characterized by differences in women's orientations towards their body weight and their diet and physical activity patterns across pregnancy and the postpartum period, emerged from the data. Only a few women diverged from prepregnancy trajectories in weight orientation and diet and physical activity patterns postpartum. Delayed resumption of prepregnancy physical activity and dietary patterns contributed to postpartum weight retention for a subset of "exercisers". Stress and age- or role-related changes in perspective interrupted the continuity of weight orientations and behavioral patterns for three other women. These findings highlight the direction and momentum provided by trajectories in health attitudes and strategies as processes shaping responses to a life transition.

Nutrition and health outcomes associated with food insecurity and hunger.

This paper explores how food insecurity and hunger relate to health and nutrition outcomes in food-rich countries such as the United States. It focuses on two subgroups of the population for whom data are available: women of childbearing age and school-age children. Special consideration is given to examining how food insecurity relates to these outcomes independently of socioeconomic status and poverty. In a population-based sample of women of childbearing age, the least severe level of food insecurity (household food insecurity) was correlated with higher body mass index (BMI), controlling for other available and known influences on obesity including income level. In low income school-age children from two large urban areas of the U.S., risk of hunger and hunger were associated with compromised psychosocial functioning, controlling for maternal education and estimated household income. The nutrition and health consequences of food insecurity comprise a potentially rich area for future, socially relevant research in the field of nutritional sciences.

Ethical issues in studying submissions to a medical journal.

A protocol to prospectively study characteristics of meta-analyses submitted to a weekly medical journal raised several ethical issues. In submitting a manuscript for publication, authors do not implicitly consent to have their work used for research. Authors must be free to refuse to consent, without it affecting their chances for publication. Systematically analyzing data on manuscript characteristics might influence the decision to publish. Having investigators who are not on the editorial staff or peer reviewers extract the manuscripts' characteristics breaks the confidentiality of the author-editor-reviewer relationship. In response to these issues, we added a statement to our journal's instructions for authors that submitted manuscripts may be systematically analyzed to improve the quality of the editorial or peer review process. Authors had to actively consent to participate, but editors and external reviewers were unaware of which authors were participating. The manuscript characteristics were not shared with authors, editors, or external reviewers. The investigators were blinded to each manuscript's author and institution. After we addressed ethical issues encountered in studying manuscripts submitted to a medical journal, 99 of 105 authors submitting a meta-analysis during the study's first 24 months agreed to participate.

Food insufficiency exists in the United States: results from the third National Health and Nutrition Examination Survey (NHANES III).

OBJECTIVES: The purpose of this study was to estimate the prevalence of food insufficiency in the United States and to examine sociodemographic characteristics related to food insufficiency. METHODS: Data were analyzed from the third National Health and Nutrition Examination Survey, a cross-sectional representative sample of the civilian noninstitutionalized population living in households. Individuals were classified as "food insufficient" if a family respondent reported that the family sometimes or often did not get enough food to eat. RESULTS: From 1988 through 1994, the overall prevalence of food insufficiency was 4.1% and was primarily related to poverty status. In the low-income population, food insufficiency was positively associated with being Mexican American, being under the age of 60, having a family head who had not completed high school, participating in the Food Stamp Program, and not having health insurance. It was not related to family type or employment status of the family head. Over half of food-insufficient individuals lived in employed families. CONCLUSIONS: Food insufficiency is not limited to very low-income persons, specific racial/ethnic groups, family types, or the unemployed. Understanding food insufficiency is critical to formulating nutrition programs and policies.

Hunger and food insecurity in the elderly: its nature and measurement.

To better understand the nature of food insecurity in the elderly and to improve its measurement, in-depth interviews were conducted with 41 urban Black and rural White elderly in 35 households, followed by telephone administration of commonly used measures of food insecurity in 24 of these elderly. Elderly food insecurity appears to follow a progression of severity, beginning with compromised diet quality, followed by food anxiety, socially unacceptable meals, use of emergency food strategies, and finally actual hunger. The five quantitative measures tested were compared to each elderly person's food insecurity status based on the in-depth interview. All measures had reasonable specificity, and good sensitivity for those experiencing severe food insecurity. However, the Cornell-Radimer, Community Childhood Hunger Identification Project (CCHIP) and Nutrition Screening Initiative (NSI) measures appeared more sensitive than the USDA food sufficiency or Urban Institute measures in correctly identifying those in the lesser stages of food insecurity.