Current validated neonatal body composition methods are limited/impractical for use outside of a clinical setting because they are labor intensive, time consuming, and require expensive equipment. The purpose of this study was to develop an anthropometric model to estimate neonatal fat mass (kg) using an air displacement plethysmography (PEA POD® Infant Body Composition System) as the criterion.

Background: More people than ever are considered obese and the resulting health problems are evident. These facts highlight the need for identification of critical time periods for weight gain. Therefore the purpose was to assess potential changes that occur in body weight during the Thanksgiving holiday break in college students. Methods: 94 college students (23.0 ± 4.6 yrs, 72.1 ± 14.0 kg, 172.6 ± 9.3 cm, 24.0 ± 3.9 kg/m²) reported to the human body composition laboratory at the University of Oklahoma following a 6-hour fast with testing occurring prior to, and immediately following the Thanksgiving holiday break (13 ± 3 days). Body weight (BW) was assessed using a balance beam scale while participants were dressed in minimal clothing. Paired t-tests were used to assess changes in BW pre and post Thanksgiving holiday with additional analysis by gender, body mass index (BMI), and class standing (i.e. undergraduate vs. graduate). Results: Overall, a significant (P < 0.05) increase in BW was found between pre (72.1 kg) and post (72.6 kg) Thanksgiving holiday. When stratified by gender and class standing a significant (P < 0.05) increase in body weight was observed between the pre and post Thanksgiving holiday in males (0.6 kg), females (0.4 kg) and graduate students (0.8 kg). When participants were classified by BMI as normal or as overweight/obese, a significant 1.0 kg BW gain was found (P < 0.05) in the overweight/obese (≥25 kg/m²) group compared to a non significant 0.2 kg gain in the normal group (<25 kg/m²). Conclusion: These data indicate that participants in our study gained a significant amount of BW (0.5 kg) during the Thanksgiving holiday. While an increase in BW of half a kilogram may not be cause for alarm, the increase could have potential long-term health consequences if participants retained this weight gain throughout the college year. Additionally, because the overweight/obese participants gained the greatest amount of BW, this group may be at increased risk for weight gain and further obesity development during the holiday season.

In newborns and children, body fat estimation equations are often used at different ages than the age used to develop the equations. Limited validation studies exist for newborn body fat estimation equations at birth or later in infancy. The study purpose was to validate 4 newborn fat mass (FM) estimation equations in comparison to FM measured by air displacement plethysmography (ADP; the Pea Pod) at birth and 3 months. Ninety-five newborns (1–3 days) had their body composition measured by ADP and anthropometrics assessed by skinfolds. Sixty-three infants had repeat measures taken (3 months). FM measured by ADP was compared to FM from the skinfold estimation equations (Deierlein, Catalano, Lingwood, and Aris). Paired t-tests assessed mean differences, linear regression assessed accuracy, precision was assessed by R2 and standard error of the estimate (SEE), and bias was assessed by Bland-Altman plots. At birth, FM measured by ADP differed from FM estimated by Deierlein, Lingwood and Aris equations, but did not differ from the Catalano equation. At 3 months, FM measured by ADP was different from all equations. At both time points, poor precision and accuracy was detected. Bias was detected in most all equations. Poor agreement, precision, and accuracy were found between prediction equations and the criterion at birth and 3 months.

Background: With the rapid increase in obesity rates, determining critical periods for weight gain and the effects of changes in fat mass is imperative. The purpose of this study was to examine changes in body weight and composition over the holiday season (Thanksgiving through New Year's) in male and female college students. Methods: Subjects completed three visits: the first occurred within 2 weeks prior to Thanksgiving, the second occurred within 5 to 7 days following Thanksgiving, and the third occurred within 10 days following New Year's Day. A total of 82 healthy male and female college age subjects participated. Body composition by dual energy x-ray absorptiometry (DXA) was assessed at visits 1 and 3 while body weight was assessed at all three visits. Results: Average body weight remained relatively unchanged from pre-Thanksgiving to post-New Year's (71.3 ± 14 kg vs. 71.2 ± 15 kg; P = 0.71) and, in fact, a subset of normal weight subjects lost a significant amount of body weight. However, percent body fat (25.9 ± 9 %fat vs. 27.0 ± 9 %fat; P < 0.01) and fat mass (18.3 ± 8 kg and 19.1 ± 8 kg; P < 0.01) significantly increased from pre-Thanksgiving to post-New Year's while fat-free mass (48.7 ± 12 kg and 48.3 ± 11 kg; P = 0.08) was not significantly different than the post-New Year's. A significant positive relationship (P < 0.001) between the change in BMI and percent fat, total fat mass, total fat free mass, and trunk fat mass for the pre-Thanksgiving and post-New Year's visits were found. The same significant positive relationships (P < 0.001) were also observed between the change in body weight and percent fat, total fat mass, total fat free mass, and trunk fat mass. Conclusion: Despite the fact that body weight remained unchanged over the course of the holiday season, a significant increase in %body fat and fat mass was observed. With recent evidence showing marked morbidity and mortality to be associated with increased body fat (particularly abdominal adiposity), results from this study suggest body weight alone may underestimate the potentially deleterious effects of the holiday season.

Formulas often contain high amounts of added sugars, though little research has studied their connection to obesity. This study assessed the contribution of added sugars from formulas during complementary feeding on total added sugar intakes, and the association between these sugars and upward weight-for-age percentile (WFA%) crossing (i.e., participants crossing a higher threshold percentile were considered to have an upward crossing). Data from three 24-hour dietary recalls for infants (n = 97; 9–12 months) and toddlers (n = 44; 13–15 months) were obtained in this cross-sectional analysis. Foods and beverages with added sugars were divided into 17 categories. Pearson's correlations were used to test relations between added sugar intake and upward WFA% crossing, followed by multivariable regressions when significant. ANOVA compared intakes of all, milk-based, and table foods between primarily formula-fed compared with breastfed participants. Multivariable regressions were used to test effects of added sugars and protein from all foods compared with added sugars and protein from milk-based sources on upward WFA% crossing. Added sugars from formulas comprised 66% and 7% of added sugars consumed daily by infants and toddlers, respectively. A significant association was observed between upward WFA% crossing and added sugars from milk-based sources after controlling for gestational age, sex, age, introduction to solid foods, mean energy intakes, and maternal pre-pregnancy BMI and education (β = 0.003; 95% CI, 0.000–0.007; P = 0.046). Primarily formula-fed participants consumed nearly twice the energy from added sugars (P = 0.003) and gained weight faster (upward WFA% crossing = 1.1 ± 1.2 compared with 0.3 ± 0.6, respectively; P < 0.001) than their breastfed counterparts. Added sugars in formulas predict rapid weight gain in infants and toddlers. Educating mothers on lower-sugar options may enhance childhood obesity prevention.