M. Loring Bradlee

Does early physical activity predict body fat change throughout childhood

BACKGROUND Declining levels of physical activity in the population at large may be responsible in part for the rising rates of childhood obesity. Studies to date, however, have not consistently demonstrated such a protective effect. We used longitudinal data from the Framingham Childrens Study (FCS) to address this important question. METHODS We used 8 years of activity monitoring (Caltrac electronic motion sensors) and repeated anthropometry measures for 103 children to examine the effect of activity on body fat change from preschool to early adolescence. Longitudinal data analysis methods were employed to account for the use of repeated measures on these children. RESULTS Children in the highest tertile of average daily activity from ages 4 to 11 years had consistently smaller gains in BMI, triceps, and sum of five skinfolds throughout childhood. By early adolescence (age 11), the sum of five skinfolds was 95.1, 94.5, and 74.1 for the low, middle, and high tertiles of activity, respectively (P for trend = 0.045). This protective effect of activity was evident for both girls and boys. CONCLUSION This longitudinal study adds strong support for the hypothesis that higher levels of physical activity during childhood lead to the acquisition of less body fat by the time of early adolescence.

A prospective study of the risk of congenital defects associated with maternal obesity and diabetes mellitus

This study was designed to evaluate the effects of maternal obesity and diabetes mellitus on the risk of nonchromosomal congenital defects. We used data from 22,951 pregnant women enrolled in a prospective cohort study of early prenatal exposures and pregnancy outcome. The relative risks [prevalence ratios (PRs)] of major nonchromosomal congenital defects associated with obesity and diabetes, alone or in combination, were calculated using multiple logistic regression analysis. In this study, in the absence of diabetes, obese women (body mass index ≥28) had no higher risk, overall, of having an offspring with a major defect [PR = 0.95; 95% confidence interval (CI) = 0.62–1.5[. Their offspring, however, did have a higher prevalence of certain types of defects, including orofacial clefts; club foot; cardiac septal defects; and, to a lesser extent, hydrocephaly and abdominal wall defects. Women with pre-existing or gestational diabetes who were not obese also had no excess risk overall of having offspring affected by a major defect (PR = 0.98; 95% CI = 0.43–2.2), although they did have a higher prevalence of musculoskeletal defects. The pregnancies of women who were both obese and diabetic were 3.1 times as likely (95% CI = 1.2–7.6) to result in an offspring with a defect than were those of nonobese, nondiabetic women, which suggests that obesity and diabetes mellitus may act synergistically in the pathogenesis of congenital anomalies. The defects were largely craniofacial or musculoskeletal.

Intake of Fruits, Vegetables, and Dairy Products in Early Childhood and Subsequent Blood Pressure Change

Background: Diets characterized by high intakes of fruits and vegetables and low-fat dairy products (for example, the DASH diet) have been shown to reduce blood pressure in adults. The effects of similar diets on childrens blood pressure are unknown. Methods: We used 8 years of follow-up data from 95 children, initially 3 to 6 years of age at enrollment in the prospective Framingham Childrens Study in 1986. The yearly clinic visits included 5 measures of blood pressure obtained with an automated device. Diet was assessed by means of replicate sets of 3-day food diaries during each year. Results: Children who consumed more fruits and vegetables (4 or more servings per day) or more dairy products (2 or more servings per day) during the preschool years had smaller yearly gains in systolic blood pressure throughout childhood. By the time of early adolescence, children with higher intakes of fruits and vegetables and dairy products had an adjusted mean (± standard deviation) systolic blood pressure of 106 ± 2.9 mm Hg, whereas those with lower intakes in both food groups had a mean systolic blood pressure of 113 ±1.5 mm Hg. Those with higher intakes of fruits and vegetables alone or dairy alone had intermediate levels of systolic blood pressure in adolescence. The effects on diastolic blood pressure were weaker. Conclusion: These results suggest that a diet rich in fruits, vegetables, and dairy products may have beneficial effects on blood pressure during childhood.

Low Dairy Intake in Early Childhood Predicts Excess Body Fat Gain

Objective: To estimate the effect of dairy intake in early childhood on the acquisition of body fat throughout childhood.

Folate Intake and the Risk of Neural Tube Defects: An Estimation of Dose-Response

Background. Studies have shown that folic acid supplementation in early pregnancy markedly reduces the risk of neural tube defects (NTDs). Investigation of the relation between relative dose of supplemental folic acid or total folate intake and NTD risk is limited. Methods. We used data from 23,228 women, predominantly from the northeastern United States, enrolled between October 1984 and June 1987 in a prospective study of early prenatal exposures and pregnancy outcomes. Diet and vitamin intake data were gathered in the early second trimester. NTDs were ascertained through prenatal testing and by report of the delivering physician. Data analyses included multiple logistic regression and restricted spline regression modeling. Results. For each additional 500 dietary folate equivalents consumed per day, the prevalence of NTDs decreased by 0.78 cases (95% confidence interval [CI] = 0.47–1.09) per 1,000 pregnancies. Compared with women having the lowest total folate intakes (0–149 folate equivalents per day), the prevalence of NTDs declined by 34%, 30%, 56% and 77% among the offspring of those women consuming 150–399, 400–799, 800–1199 and ≥ 1200 folate equivalents per day, respectively (P-value for linear trend = 0.016). Conclusions. Our results suggest that NTD risk declines markedly with modest increases of total folate in early pregnancy. Total folate dose, rather than supplemental folate alone, should be considered in formulating public health guidelines for NTD prevention.

Dairy Intake and Anthropometric Measures of Body Fat among Children and Adolescents in NHANES

Objective: To explore the relation between dairy intake and body fat among children and adolescents. Materials and Methods: Children (5–11 years) and adolescents (12–16 years) were included who had data on diet, anthropometry measures of body fat, and relevant potential confounders (children: n = 3,864 and 2,231; adolescents: n = 1,884 and 2,636 in NHANES III and NHANES 1999–2002, respectively). Each childs daily dairy intake from 24-hour recalls was classified as low, moderate or high. For girls and boys, respectively: low intake: <1 and <2 servings; moderate intake: 1–<3 and 2–<4 servings; and high intake: ≥3 and ≥4 servings per day.) Analysis of covariance was used to control for potential confounding by age, gender, socio-economic status, race/ethnicity, height and television watching. Results: Among children, there was no consistent association between dairy intake and anthropometric indices of body fat. Among adolescents, the lowest dairy intake group (< one serving per day for girls and < two per day for boys) had higher estimated levels of body fat than those in the highest dairy group. Compared with the lowest intake level, adolescent girls in NHANES III who consumed 1–<3 servings per day of dairy had about 2.5 mm less subcutaneous body fat (95% CI: −4.70 mm, −0.39 mm) while girls consuming three or more servings had about 5 mm less fat in their sum of two skinfolds. Adolescent boys consuming 4 or more servings of dairy per day had lower anthropometry levels than did those consuming less than two servings. Conclusion: Among adolescents, suboptimal dairy intake was associated with higher anthropometric measures of body fat.

Effects of Average Childhood Dairy Intake on Adolescent Bone Health

OBJECTIVE To evaluate the effects of usual childhood dairy intake on adolescent bone health. STUDY DESIGN Dietary data collected in the Framingham Childrens Study over 12 years were used to evaluate usual dairy consumption and adolescent bone health. Each childs average Food Pyramid servings were estimated from yearly sets of 3-day diet records. Bone mineral content (BMC) and area (BA) for total body and 6 regions (arms, legs, trunk, ribs, pelvis, and spine) at ages 15 to 17 years were the primary outcomes. Analysis of covariance was used to adjust for potential confounding by sex and physical activity, as well as age, height, body mass index and percent body fat at the time of the bone scan. RESULTS Consuming >or= 2 servings/day of dairy (versus less) was associated with significantly higher mean BMC and BA. Higher intakes of meats/other proteins (>or= 4 servings per/day) were also associated with higher mean BMC and BA values. Children with higher intakes of both dairy and meats/other proteins had the highest adjusted BMC (3090.1 g), and children consuming less of each had the lowest BMC (2740.2 g). CONCLUSIONS These prospective data provide evidence for a beneficial effect of childhood dairy consumption on adolescent bone health.

Dietary Approaches to Stop Hypertension (DASH) eating pattern and risk of elevated blood pressure in adolescent girls.

Dietary determinants of adolescent blood pressure (BP) are poorly understood. The goal of the present study was to assess the effects of an eating pattern similar to that from the Dietary Approaches to Stop Hypertension (DASH) study on adolescent BP. Data from 2185 girls followed-up over 10 years (until the girls were 18-20 years of age) in the National Heart Lung and Blood Institutes Growth and Health Study were used in this analysis. Diet was assessed during eight examination cycles using 3 d dietary records; girls were classified according to their consumption of foods associated with a DASH-style eating pattern. Analysis of covariance modelling, multiple logistic regression and longitudinal mixed models were used to control for potential confounding by age, race, socio-economic status, height, physical activity, television viewing time and other dietary factors. Girls who consumed ≥ 2 daily servings of dairy and ≥ 3 servings of fruits and vegetables (FV) had a 36 % lower risk (95 % CI: 0·43, 0·97) of elevated BP (EBP) in late adolescence. In longitudinal modelling, two dietary factors were associated with a lower systolic BP throughout adolescence: higher (≥ 2 daily servings) dairy intakes (P < 0·0001) and a DASH-style pattern (P = 0·0002). Only the DASH-style pattern led to consistently lower diastolic BP levels (P = 0·0484). Adjustment for BMI did not appreciably modify the results. In this study, adolescent girls whose diets were rich in dairy products and FV during the early- and mid-adolescent years were less likely to have EBP levels in later adolescence.

Beverage intake in early childhood and change in body fat from preschool to adolescence.

BACKGROUND Childhood obesity is closely associated with adult obesity, hypertension, and cardiovascular disease. This studys aim was to determine the effects of beverage intake patterns on body composition from early childhood into adolescence in the Framingham Childrens Study. METHODS Multiple sets of 3-day records were used to assess diet over 12 years, beginning in 1987, in 103 non-Hispanic white boys and girls. BMI, waist circumference, and four skinfolds (triceps, subscapular, suprailiac, and abdominal) were measured yearly. Percent body fat was assessed by dual-energy X-ray absorptiometry at end of follow-up. Analysis of covariance and longitudinal mixed modeling were used to control for potential confounding by age, baseline body fat, percent of energy from fat, television/video viewing time, other beverage intakes not included in exposure group, mothers education, and BMI. RESULTS Children with the lowest milk intakes in early childhood had 7.4% more body fat in later adolescence than those with higher intakes (30.0% body fat in tertile 1 vs. 22.6% in tertile 3; p=0.0095). Fruit and vegetable juice was similarly protective-those in the highest tertile of fruit and vegetable juice intake during childhood had an 8.0-cm smaller waist circumference at 15-17 years of age, compared with those in the lowest tertile (p=0.0328). There was no relation between sugar-sweetened beverages (SSBs) and percent body fat (p=0.9296) or other outcomes. CONCLUSIONS These results suggest that adequate intakes of milk and fruit and vegetable juice may reduce the risk of excess body fat in later childhood and adolescence. Further, modest intakes of SSBs in early childhood may not adversely affect body fat change.

Food Group Intake and Micronutrient Adequacy in Adolescent Girls

This study explores the contribution of food group intakes to micronutrient adequacy among 2379 girls in the National Growth and Health Study during three age periods (9–13, 14–18, and 19–20 years). Data on food and nutrient intakes from 3-day diet records over 10 years were used to estimate mean intakes and percent meeting Dietary Guidelines (DGA) recommendations for food intakes and Institute of Medicine’s recommendations for vitamins and minerals. More than 90% of girls failed to consume the recommended amounts of fruit, vegetables and dairy; 75% consumed less than the recommended amounts in the “meat” group. The vast majority of girls of all ages had inadequate intakes of calcium, magnesium, potassium, and vitamins D and E. In contrast, they consumed >750 kcal/day (~40% of total energy) from the DGA category of solid fat and added sugars, about five times the recommended maximum intakes. This study shows the importance of consuming a variety of foods in all five food groups, including those that are more energy dense such as dairy and meats, in order to meet a broad range of nutrient guidelines. Diet patterns that combined intakes across food groups led to greater improvements in overall nutritional adequacy.