The accuracy of neck circumference for assessing overweight and obesity: a systematic review and meta-analysis.

CONTEXT: Neck circumference (NC) has been suggested as an alternative measure to screen for excess body weight. OBJECTIVE: The aim of this study was to demonstrate the accuracy of neck circumference (NC) as a measure for assessing overweight and obesity in both sexes in different age groups. METHODS: Detailed individual search strategies were developed for each of the following bibliographic databases: Cochrane, LILACS, PubMed/MEDLINE, Science Direct, Scopus and Web of Science. The QUADAS-2 checklist was used to assess the methodology of the studies included. RESULTS: Thirty-eight assessments were performed in 11 articles according to age, sex and weight status. Using sensitivity and specificity, 27 assessments (71.0%) considered NC an accurate measure to diagnose overweight and obesity. The best sensitivity and specificity were found for the age >19 years (82.0%, 82.0%), female (80.0%, 73.0%), and obese (80.0%, 85.0%) categories. CONCLUSION: NC is an accurate tool for assessing overweight and obesity in males and females of different age groups and could be used to screen for excess body weight in routine medical practice or epidemiological studies. It is also believed that more studies will permit the creation of a reference dataset of NC cut-off values for world populations.

The Independent Importance of Pre-pregnancy Weight and Gestational Weight Gain for the Prevention of Large-for Gestational Age Brazilian Newborns.

Objectives To study the independent effect of pre-pregnancy weight, gestational weight gain (GWG), and other important risk factors on newborn birth weight. Methods Baseline data of 435 adult women and their singletons born between January and February 2012 at a public hospital in Brazil were used. Logistic regression was applied to determine the independent importance of pre-pregnancy weight and GWG for large for gestational age (LGA) newborns. Results Among all mothers, 37.9 % were overweight and obese before pregnancy and 45.3 % experienced excessive GWG. Among the newborns, 24.4 % were classified as LGA. Univariate analysis showed an association of family income, GWG, pre-pregnancy BMI and excessive GWG with LGA newborns. Smoking before and during pregnancy was associated with a decreased likelihood of giving birth to an LGA newborn compared to mothers who did not smoke. After adjustment for confounding variables, age at birth of first child, GWG, HbA1c and pre-pregnancy weight-GWG were significant and independent determinants of giving birth to an LGA newborn. Mothers with pre-pregnancy overweight and excessive GWG were more likely to deliver an LGA newborn (OR 2.54, P < 0.05) compared to mothers who were normal weight and experienced adequate GWG. Conclusions for Practice Age at first birth of child, GWG, HbA1c and pre-pregnancy overweight combined with excessive GWG are independent determinants of LGA newborns. The results of this study suggest that both primary prevention of overweight in women of childbearing age and management of GWG may be important strategies to reduce the number of LGA newborns and, consequently, the long-term public health burden of obesity.