The Common Variant in the FTO Gene Did Not Modify the Effect of Lifestyle Changes on Body Weight: The Finnish Diabetes Prevention Study

The common single‐nucleotide polymorphism in the FTO (fat mass and obesity associated) gene is consistently associated with an increased risk of obesity. However, the knowledge of a potential modifying effect of the FTO gene on changes in body weight achieved by lifestyle intervention is limited. We examined whether the FTO gene variant (rs9939609, T/A) is associated with body weight and BMI and long‐term weight changes in the Finnish Diabetes Prevention Study (DPS). Altogether, 522 (aged 40–65 years; BMI ≥25 kg/m²) subjects with impaired glucose tolerance (IGT) were randomized to control and lifestyle intervention groups. SNP rs9939609 was genotyped from 502 subjects. At baseline, those with the AA genotype had higher BMI than subjects with other genotypes (P = 0.006). The association was observed in women (P = 0.016) but not in men. During the 4‐year follow‐up, the subjects with the AA genotype had consistently the highest BMI (P = 0.009) in the entire study population. The magnitude of weight reduction was greater in the intervention group, but the risk allele did not modify weight change in either of the groups. Our results confirm the association between the common FTO variant and BMI in a cross‐sectional setting and during the long‐term lifestyle intervention. We did not observe association between FTO variant and the magnitude of weight reduction achieved by long‐term lifestyle intervention. Based on the results from the DPS, it is unlikely that the common variant of the FTO gene affects the success of lifestyle modification on weight loss.     

Sedentary behavior, recreational physical activity, and 7-year weight gain among postmenopausal U.S. women

Objective: To assess the relationship among recreational physical activity (PA), non‐occupational sedentary behavior, and 7‐year weight gain among postmenopausal U.S. women 40 to 69 years old. Research Methods and Procedures: In 1992 and 1999, 18,583 healthy female participants from the Cancer Prevention Study II Nutrition Cohort completed questionnaires on anthropometric characteristics and lifestyle factors. The associations between recreational PA [in metabolic equivalent (MET) hours per week] and non‐occupational sedentary behavior (in hours per day) at baseline and risk for 7‐year weight gain (5 to 9 or ≥10 vs. ±4 pounds) were assessed using multivariate logistic regression analysis. Results: Neither PA nor sedentary behavior was associated with a 5‐ to 9‐pound weight gain. Among women who were not overweight at baseline (BMI <25.0), the odds of ≥10‐pound weight gain were 12% lower (odds ratio, 0.88; 95% confidence interval, 0.77 to 0.99) for those in the highest category of recreational PA (≥18 MET h/wk) compared with >0 to <4 MET h/wk; odds were 47% higher (odds ratio, 1.47; 95% confidence interval, 1.21 to 1.79) for non‐overweight women who reported ≥6 h/d of non‐occupational sedentary behavior compared with <3 h/d. Neither PA nor sedentary behavior were associated with risk of ≥10‐pound weight gain weight among women who were overweight at baseline (BMI ≥25.0). Discussion: Both recreational PA and non‐occupational sedentary behavior independently predicted risk of ≥10‐pound weight gain among postmenopausal women who were not overweight at baseline. Public health messages to prevent weight gain among normal‐weight postmenopausal women may need to focus on decreasing time spent in sedentary behaviors and increasing the amount of time spent on PA.     

Disparities in counseling for lifestyle modification among obese adults: insights from the Dallas Heart Study

Clinician counseling is a catalyst for lifestyle modification in obesity. Unfortunately, clinicians do not appropriately counsel all obese patients about lifestyle modification. The extent of disparities in clinician counseling is not well understood. Obese participants (BMI ≥30 kg/m², N = 2097) in the Dallas Heart Study (DHS), a probability‐based sample of Dallas County residents ages 18–65, were surveyed regarding health‐care utilization and lifestyle counseling over the year prior to DHS enrollment. Health‐care utilization and counseling were compared between obese participants across three categories based on the presence of 0, 1, or 2+ of the following cardiovascular (CV) risk factors: hypertension, hypercholesterolemia, or diabetes. Logistic regression modeling was used to determine likelihood of counseling in those with 0 vs. 1+ CV risk factors, stratified by race, adjusting for age, sex, insurance status, and education. Among obese subjects who sought medical care, those with 0 CV risk factors, compared to those with 1 or 2+ CV risk factors, were less likely to report counseling about losing weight (41% vs. 67% vs. 87%, P trend <0.001), dietary changes (44% vs. 71% vs. 85%, P trend <0.001), and physical activity (46% vs. 71% vs. 86%, P trend <0.001). Blacks and Hispanics without CV risk factors had a lower odds of receiving counseling than whites without risk factors on weight loss (adjusted odds ratio (OR), 95% confidence interval (CI) for nonwhites 0.19, [0.13–0.28], whites 0.48, [0.26–0.87]); dietary changes (nonwhites 0.19, [0.13–0.27], whites 0.37, [0.21–0.64]); and physical activity (nonwhites 0.22, [0.16–0.32], whites 0.32, [0.18–0.57]). Lifestyle counseling rates by clinicians are suboptimal among obese patients without CV risk factors, especially blacks and Hispanics. Systematic education about and application of lifestyle interventions could capitalize on opportunities for primary CV risk prevention.     

Varying patterns of BMI increase in sex and birth cohorts of Korean adults

Objective: The Korean population has recently experienced a rapid increase in obesity associated with lifestyle changes arising from economic growth. We examined trends in BMI by analyzing sex‐specific birth cohorts using 3,400,727 measurements from 1,662,477 Korean adults. Research Methods and Procedures: Birth cohort data were collected from the employees of government organizations and schools and their dependents, 20 to 65 years of age, who participated in health examinations provided by the Korean National Health Insurance Corporation in 1992, 1996, and 2000. Results: The prevalence of obesity (BMI ≥ 30 kg/m²) was 0.8% among men and 0.3% among women in 1992, but by 2000, it had increased 2.5‐fold to 2.0% in men and 2.3‐fold to 0.7% in women. Over the 8‐year period, the mean BMI increased 0.8 kg/m² in men and 0.3 kg/m² in women. The rate of BMI increase over the 8 years varied markedly among the sex‐specific birth cohorts, with the steepest slopes representing the youngest men (0.2 kg/m² per year). Discussion: National health promotion activities should target younger men to prevent an increase in obesity‐related morbidity and mortality.     

High visceral fat mass and high liver fat are associated with resistance to lifestyle intervention

Objective: High visceral adipose tissue (VAT) and high liver fat (LF) are associated with the metabolic syndrome and diabetes. We studied changes in these two fat depots during weight loss and analyzed whether VAT and LF at baseline predict the response to lifestyle intervention. Research Methods and Procedures: One hundred twelve subjects (48 men and 64 women; age, 46 ± 11 years; BMI, 29.2 ± 4.4 kg/m²) were studied after a follow up‐time of 264 ± 60 (SD) days. Insulin sensitivity was estimated from the oral glucose tolerance test. Body fat depots were quantified using magnetic resonance imaging and spectroscopy. Results: Cross‐sectionally high VAT (r = ?0.22, p = 0.02) and high LF (r = ?0.36, p < 0.0001) were independently associated with low insulin sensitivity. With intervention, BMI (?3.0%), VAT (?12.0%), and LF (?33.0%) were reduced (all p < 0.001). Insulin sensitivity was improved (+17%, p < 0.01). The changes in BMI (r = ?0.41), VAT (r = ?0.28), and LF (r = ?0.39) were associated with the increase in insulin sensitivity (all p < 0.01). High VAT (r = ?0.28, p = 0.01) and high LF (r = ?0.38, p < 0.01) at baseline were associated with a lesser increase in insulin sensitivity. Discussion: Baseline values and changes in BMI, VAT, and LF are related to changes in insulin sensitivity during lifestyle intervention. Subjects with high VAT and LF have a lower chance of profiting from lifestyle intervention and may require intensified lifestyle prevention strategies or even pharmacological approaches to improve insulin sensitivity.     

Profile of Overweight and Obese People in a Mediterranean Region

Objective: To assess the prevalence of excess weight (obesity and overweight) and the related environmental risk factors in a Mediterranean population. Self‐perception of body weight, attitudes toward weight‐control behaviors, and the associated factors were also examined. Research Methods and Procedures: A cross‐sectional nutritional survey was carried out in the Balearic Islands between 1999 and 2000. A random sample (n = 1200) of the adult population (20 to 60 years old) was interviewed. Dietary questionnaires and a global questionnaire incorporating questions related to sociodemographic and lifestyle variables were utilized. Anthropometric measurements were also obtained. Results: Nearly one‐half of the population of the Balearic Islands is above the normal weight range (BMI > 25). The predictors of overweight and obesity in the Balearic Islands are to be over 40 years old, to be married, to form part of the lowest educational levels, and to have a sedentary lifestyle. A large percentage of excess‐weight individuals tend to underestimate their BMI, are not concerned about their weight status, tend to snack more often, and have never dieted. Discussion: Although the likely causes of the rise in obesity prevalence are difficult to elucidate from this study, we have identified the profile of individuals with excess weight in the Balearic Islands as well as their attitudes toward their body image.     

Body Mass Index and the Prevalence of Hypertension and Dyslipidemia

Objective: To describe and evaluate relationships between body mass index (BMI) and blood pressure, cholesterol, high‐density lipoprotein‐cholesterol (HDL‐C), and hypertension and dyslipidemia. Research Methods and Procedures: A national survey of adults in the United States that included measurement of height, weight, blood pressure, and lipids (National Health and Nutrition Examination Survey III 1988–1994). Crude age‐adjusted, age‐specific means and proportions, and multivariate odds ratios that quantify the association between hypertension or dyslipidemia and BMI, controlling for race/ethnicity, education, and smoking habits are presented. Results: More than one‐half of the adult population is overweight (BMI of 25 to 29.9) or obese (BMI of ≥30). The prevalence of high blood pressure and mean levels of systolic and diastolic blood pressure increased as BMI increased at ages younger than 60 years. The prevalence of high blood cholesterol and mean levels of cholesterol were higher at BMI levels over 25 rather than below 25 but did not increase consistently with increasing BMI above 25. Rates of low HDL‐C increased and mean levels of HDL‐C decreased as levels of BMI increased. The associations of BMI with high blood pressure and abnormal lipids were statistically significant after controlling for age, race or ethnicity, education, and smoking; odds ratios were highest at ages 20 to 39 but most trends were apparent at older ages. Within BMI categories, hypertension was more prevalent and HDL‐C levels were higher in black than white or Mexican American men and women. Discussion: These data quantify the strong associations of BMI with hypertension and abnormal lipids. They are consistent with the national emphasis on prevention and control of overweight and obesity and indicate that blood pressure and cholesterol measurement and control are especially important for overweight and obese people.     

Assessing the Validity of Body Mass Index Standards in Early Postmenopausal Women

Objective: To examine the relationship between percentage of total body fat (%Fat) and body mass index (BMI) in early postmenopausal women and to evaluate the validity of the BMI standards for obesity established by the NIH. Research Methods and Procedures: Three hundred seventeen healthy, sedentary, postmenopausal women (ages, 40 to 66 years; BMI, 18 to 35 kg/m²; 3 to 10 years postmenopausal) participated in the study. Height, weight, BMI, and %Fat, as assessed by DXA, were measured. Receiver operating characteristic analysis was performed to evaluate the ability of BMI to discriminate obesity from non‐obesity using 38%Fat as the criterion value. Results: A moderately high relationship was observed between BMI and %Fat (r = 0.81; y = 1.41x + 2.65) with a SE of estimate of 3.9%. Eighty‐one percent of other studies examined fell within 1 SE of estimate as derived from our study. Receiver operating characteristic analysis showed that BMI is a good diagnostic test for obesity. The cutoff for BMI corresponding to the criterion value of 38%Fat that maximized the sum of the sensitivity and specificity was 24.9 kg/m². The true‐positive (sensitivity) and false‐positive (1 ? specificity) rates were 84.4% and 14.6%, respectively. The area under the curve estimate for BMI was 0.914. Discussion: There is a strong association between %Fat and BMI in postmenopausal women. Current NIH BMI‐based classifications for obesity may be misleading based on currently proposed %Fat standards. BMI >25 kg/m² rather than BMI >30 kg/m² may be superior for diagnosing obesity in postmenopausal women.     

Girls' perception of neighborhood factors on physical activity, sedentary behavior, and BMI

Objective: The purpose of this study was to examine the association of perceived physical neighborhood factors with physical activity, sedentary behavior, and BMI among adolescent girls. Research Methods and Procedures: Sixth grade girls (n = 1554) completed a questionnaire on neighborhood factors (e.g., safety, esthetics, access to physical activity resources). The dependent variables included non‐school metabolic equivalent weighted moderate to vigorous physical activity (MW‐MVPA) and non‐school sedentary behavior, both measured using accelerometry, and BMI. Results: The following neighborhood factors were associated with lower BMI: seeing walkers and bikers on neighborhood streets, not having a lot of crime in the neighborhood, seeing other children playing outdoors, having bicycle or walking trails in the neighborhood, and access to physical activity facilities. The absolute contribution for the average girl for each of these neighborhood factors was relatively small, with none of these factors exceeding 0.8 kg/m² BMI units. The following neighborhood factors were associated with higher MW‐MVPA: having well‐lit streets at night, having a lot of traffic in the neighborhood, having bicycle or walking trails in the neighborhood, and access to physical activity facilities. Girls with ≥9 places to go for physical activity had 14.0% higher non‐school MW‐MVPA than girls with ≤4 places. Discussion: This study identified several neighborhood factors associated with non‐school MW‐MVPA and BMI, but none of the factors explored were associated with non‐school sedentary behavior. Of all of the neighborhood factors we examined, reporting more physically active destinations contributed the largest absolute amount to the average girl's non‐school MW‐MVPA, according to this cross‐sectional study.     

Cardiorespiratory fitness and sedentary activities are associated with adiposity in adolescents

Objective: To determine whether physical activity, sedentary activities, and/or cardiorespiratory fitness are related to waist circumference in adolescents, as previously reported in adults. Research Methods and Procedures: The study subjects were a representative sample of Spanish adolescents (N = 2859; 1357 boys, 1502 girls; age, 13 to 18.5 years), all of whom were involved in the AVENA (Food and Assessment of the Nutritional Status of Adolescents) study. BMI, waist circumference, pubertal maturation status, and cardiorespiratory fitness were measured in all. Leisure‐time physical activity, sedentary activities, active commuting to school, and socioeconomic status were assessed by self‐reported questionnaires. Results: No relationship was found between leisure‐time physical activity and BMI or waist circumference. In contrast, and in both boys and girls and after adjustment for confounding variables, cardiorespiratory fitness was found to be inversely associated with waist circumference and BMI, independent of sedentary activities or physical activity (p ≤ 0.001). The maximum oxygen consumption explained 13% of the variance in waist circumference in boys and 16% in girls. Sedentary activities were independently and directly related to waist circumference in both boys and girls (p ≤ 0.05) and to BMI in boys (p ≤ 0.05). Sedentary activities explained 10% of the variance in waist circumference in boys and 18% in girls. The BMI‐adjusted waist circumference was inversely correlated with cardiorespiratory fitness in overweight‐obese boys (p ≤ 0.05) and showed a trend toward significance in girls (p ≤ 0.1). Discussion: Both moderate to high levels of cardiorespiratory fitness and sedentary activities, but not physical activity, are associated with lower abdominal adiposity, as measured by waist circumference.     

Central adiposity and other anthropometric factors in relation to risk of macrosomia in an african american population

Objective:

Previous studies have consistently identified maternal obesity and gestational weight gain (GWG) as risk factors for macrosomia, but little is known about the effects of central adiposity and body fat distribution. Using self‐reported data from the Black Women's Health Study (BWHS), a large follow‐up study of US black women, we examined the risk of macrosomia in relation to prepregnancy waist circumference, prepregnancy waist‐to‐hip ratio (WHR), prepregnancy BMI, and GWG.

Design and Methods:

During 1995–2003, BWHS participants ages 21–44 years delivered 6,687 full‐term singleton births (gestational age >37 weeks). We compared mothers of 691 infants weighing ≥4,000 g with mothers of 5,996 infants weighing <4,000 g. Generalized estimating equation models (GEE) that accounted for more than one birth per mother were used to estimate multivariable odds ratios (OR) and 95% confidence intervals (CI).

Results:

Independent of prepregnancy BMI, prepregnancy waist circumference was positively associated with risk of macrosomia (OR = 1.58, 95% CI: 1.07–2.32, for ≥35.0 vs. <27.0 inches (≥88.9 vs. <68.6 cm); P trend = 0.04). As expected, prepregnancy BMI was also positively associated with macrosomia (OR = 1.74, 95% CI: 1.25–2.41 for BMI ≥35.0 vs. 18.5–24.9 kg m^?2). GWG above the amount recommended by the 2009 Institute of Medicine report was associated with an increased risk of macrosomia and the association was present in each category of prepregnancy BMI (18.5–24.9, 25.0–29.9, and ≥30.0 kg m^?2; P trend <0.001).

Conclusions:

Our data suggest that overall obesity, high GWG, and high waist circumference are independent risk factors for macrosomia among US black women.

     

Fitness Alters the Associations of BMI and Waist Circumference with Total and Abdominal Fat

Objective: We tested the following hypotheses in black and white men and women: 1) for a given BMI or waist circumference (WC), individuals with moderate cardiorespiratory fitness (CRF) have lower amounts of total fat mass and abdominal subcutaneous and visceral fat compared with individuals with low CRF; and 2) exercise training is associated with significant reductions in total adiposity and abdominal fat independent of changes in BMI or WC. Research Methods and Procedures: The sample included 366 sedentary male (111 blacks and 255 whites) and 462 sedentary female (203 blacks and 259 whites) participants in the HERITAGE Family Study. The relationships between BMI and WC with total fat mass (determined by underwater weighing) and abdominal subcutaneous and visceral fat (determined by computed tomography) were compared in subjects with low (lower 50%) and moderate (upper 50%) CRF. The effects of a 20‐week aerobic exercise training program on changes in these adiposity variables were examined in 86% of the subjects. Results: Individuals with moderate CRF had lower levels of total fat mass and abdominal subcutaneous and visceral fat than individuals with low CRF for a given BMI or WC value. The 20‐week aerobic exercise program was associated with significant reductions in total adiposity and abdominal fat, even after controlling for reductions in BMI and WC. With few exceptions, these observations were true for both men and women and blacks and whites. Discussion: These findings suggest that a reduction in total adiposity and abdominal fat may be a means by which CRF attenuates the health risk attributable to obesity as determined by BMI and WC.     

Cross‐Sectional and Longitudinal Associations of BMI with Socioeconomic Characteristics

Objective: To examine cross sectional and longitudinal associations of socioeconomic position and neighborhood environments with BMI in a middle‐aged and bi‐ethnic cohort. Research Methods and Procedures: Analyses were based on 13, 167 subjects (45 to 64 years) who participated in the Atherosclerosis Risk in Communities Study, a population‐based study. Census block groups were used as proxies for neighborhoods and were characterized using a summary socioeconomic score. BMI was measured at baseline and at three follow‐up visits over a 9‐year period. Results: Individual and neighborhood socioeconomic characteristics were independently and inversely associated with BMI at baseline in women [mean difference in kilograms per meter squared per unit increase in socioeconomic category (SE) for white and black women respectively; ?1.56 (0.14), ?1.59 (0.19) for education; ?1.07 (0.10), ?1.18 (0.18) for income; and ?1.04 (0.09), ?0.77 (0.18) for neighborhood characteristics]. Results for men were not as consistent. Baseline BMI was negatively associated with income in white men but was positively associated with education, income, and neighborhood characteristics in black men. BMI increased over time regardless of gender or race and in most age groups. In whites, there were no consistently patterned differences in longitudinal trends in BMI by individual or neighborhood socioeconomic characteristics. However, in blacks, there was some evidence of greater increases in the higher socioeconomic status groups. Discussion: Socioeconomic factors are inversely associated with BMI in middle‐aged women, possibly reflecting socially patterned exposures occurring in childhood and adolescence. However, recent increases over time in BMI are either not clearly patterned by socioeconomic factors or are greater in the higher socioeconomic status groups.     

BMI,Physical Activity,and Health Care Utilization/Costs among Medicare Retirees

Objective: To examine the influence of physical activity (PA) and BMI on health care utilization and costs among Medicare retirees. Research Methods and Procedures: This cross‐sectional study was based on 42, 520 Medicare retirees in a U.S.‐wide manufacturing corporation who participated in indemnity/perferred provider and one health risk appraisal during the years 2001 and 2002. Participants were assigned into one of the three weight groups: normal weight, overweight, and obese. PA behavior was classified into three levels: sedentary (0 time/wk), moderately active (1 to 3 times/wk), and very active (4+ times/wk). Results: Generalized linear models revealed that the moderately active retirees had $1456, $1731, and $1177 lower total health care charges than their sedentary counterparts in the normal‐weight, overweight, and obese groups, respectively (p < 0.01). The very active retirees had $1823, $581, and $1379 lower costs than the moderately active retirees. Health care utilization and specific costs showed similar trends with PA levels for all BMI groups. The total health care charges were lower with higher PA level for all age groups (p < 0.01). Discussion: Regular PA has strong dose‐response effects on both health care utilization and costs for overweight/obese as well as normal‐weight people. Promoting active lifestyle in this Medicare population, especially overweight and obese groups, could potentially improve their well‐being and save a substantial amount of health care expenditures. Because those Medicare retirees are hard to reach in general, more creative approaches should be launched to address their needs and interests as well as help reduce the usage of health care system.     

Preoperative lifestyle intervention in bariatric surgery: Initial results from a randomized,controlled trial

Objective:

To document preoperative outcomes of a behavioral lifestyle intervention delivered to patients prior to bariatric surgery in comparison to treatment as usual (insurance‐mandated physician supervised diet).

Design and Methods:

After completing a baseline assessment, candidates for surgery were randomized to a 6‐month, evidence‐informed, manualized lifestyle intervention (LIFESTYLE, n = 121) or to preoperative care as usual (USUAL CARE, n = 119). At 6 months, 187 participants remained candidates for bariatric surgery and were included in the analyses.

Results:

LIFESTYLE participants lost significantly more weight than those receiving USUAL CARE [8.3 ± 7.8 kg vs. 3.3 ± 5.5 kg, F(1,183) = 23.6, P < 0.0001], with an effect size of 0.72. Additionally, logistic regression modeling indicated that LIFESTYLE patients were significantly more likely to lose at least 5% of initial body weight than those in USUAL CARE [OR (95% CI) = 2.94 (1.253, 6.903)], as were participants who were heavier [OR (95% CI) = 1.07 (1.001‐1.14) for each unit increase in BMI] or with larger improvements in eating behaviors [OR (95% CI) = 1.1 (1.049, 1.145) for each unit increase on the Eating Behavior Inventory).

Conclusions:

A behavioral lifestyle intervention for severely overweight individuals leads to clinically significant weight loss prior to bariatric surgery. Post‐surgery follow‐up will allow us to examine the impact of the preoperative intervention on postoperative outcomes.     

Higher protein intake preserves lean mass and satiety with weight loss in pre-obese and obese women

Objective: To examine the effects of dietary protein and obesity classification on energy‐restriction‐induced changes in weight, body composition, appetite, mood, and cardiovascular and kidney health. Research Methods and Procedures: Forty‐six women, ages 28 to 80, BMI 26 to 37 kg/m², followed a 12‐week 750‐kcal/d energy‐deficit diet containing higher protein (HP, 30% protein) or normal protein (NP, 18% protein) and were retrospectively subgrouped according to obesity classification [pre‐obese (POB), BMI = 26 to 29.9 kg/m²; obese (OB), BMI = 30 to 37 kg/m²). Results: All subjects lost weight, fat mass, and lean body mass (LBM; p < 0.001). With comparable weight loss, LBM losses were less in HP vs. NP (?1.5 ± 0.3 vs. ?2.8 ± 0.5 kg; p < 0.05) and POB vs. OB (?1.2 ± 0.3 vs. ?2.9 ± 0.4 kg; p < 0.005). The main effects of protein and obesity on LBM changes were independent and additive; POB‐HP lost less LBM vs. OB‐NP (p < 0.05). The energy‐restriction‐induced decline in satiety was less pronounced in HP vs. NP (p < 0.005). Perceived pleasure increased with HP and decreased with NP (p < 0.05). Lipid‐lipoprotein profile and blood pressure improved and kidney function minimally changed with energy restriction (p < 0.05), independently of protein intake. Discussion: Consuming a higher‐protein diet and accomplishing weight loss before becoming obese help women preserve LBM. Use of a higher‐protein diet also improves perceptions of satiety and pleasure during energy restriction.     

Effect of Lifestyle Modification on Adipokine Levels in Obese Subjects with Insulin Resistance

Objective: To study the effect of weight loss in response to a lifestyle modification program on the circulating levels of adipose tissue derived cytokines (adipokines) in obese individuals with insulin resistance. Research Methods and Procedures: Twenty‐four insulin‐resistant obese subjects with varying degrees of glucose tolerance completed a 6‐month program consisting of combined hypocaloric diet and moderate physical activity. Adipokines [leptin, adiponectin, resistin, tumor necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6)] and highly sensitive C‐reactive protein were measured before and after the intervention. Insulin sensitivity index was evaluated by the frequently sampled intravenous glucose tolerance test. Results: Participants had a 6.9 ± 0.1 kg average weight loss, with a significant improvement in sensitivity index and reduction in plasma leptin (27.8 ± 3 vs. 23.6 ± 3 ng/mL, p = 0.01) and IL‐6 (2.75 ± 1.51 vs. 2.3 ± 0.91 pg/mL, p = 0.012). TNF‐α levels tended to decrease (2.3 ± 0.2 vs. 1.9 ± 0.1 pg/mL, p = 0.059). Adiponectin increased significantly only among diabetic subjects. The reductions in leptin were correlated with the decreases in BMI (r = 0.464, p < 0.05) and with changes in highly sensitive C‐reactive protein (r = 0.466, p < 0.05). Discussion: Weight reduction in obese individuals with insulin resistance was associated with a significant decrease in leptin and IL‐6 and a tendency toward a decrease in circulating TNF‐α, whereas adiponectin was increased only in diabetic subjects. Further studies are needed to elucidate the relationship between changes of adipokines and the health benefits of weight loss.     

Longitudinal patterns of breakfast eating in black and white adolescent girls

Objective: The objective was to describe the pattern of breakfast eating over time (“breakfast history”) and examine its associations with BMI and physical activity. Research Methods and Procedures: This longitudinal investigation of patterns of breakfast eating included 1210 black and 1161 white girls who participated in the 10‐year, longitudinal National Heart, Lung, and Blood Institute Growth and Health Study (NGHS). Three‐day food records were collected during annual visits beginning at ages 9 or 10 up to age 19. Linear regression and path analysis were used to estimate the associations between breakfast history, BMI, and physical activity. Results: Among girls with a high BMI at baseline, those who ate breakfast more often had lower BMI at the end of the study (age 19), compared with those who ate breakfast less often. Path analysis indicated that energy intake and physical activity mediated the association between patterns of breakfast eating over time and BMI in late adolescence. Discussion: The association between regular breakfast consumption over time and moderation of body weight among girls who began the study with relatively high BMI suggests that programs to address overweight in children and adolescents should emphasize the importance of physical activity and eating breakfast consistently.     

A Longitudinal Study of Sedentary Behavior and Overweight in Adolescent Girls

The aim of this study is to examine sedentary and light activity in relation to overweight in adolescent girls. Adolescent girls were randomly recruited from 36 schools participating in the Trial of Activity for Adolescent Girls (TAAG). Assessments included age, ethnicity, socioeconomic status, and body composition estimated from weight, height, and triceps skinfold. Sedentary and light activity was measured for 6 days using accelerometry in 6th and in 8th grade among two randomly sampled cross‐sections of girls. Sedentary activity increased from the 6th to 8th grade by 51.5 min/day. In the 8th grade, a significantly higher number of hours in sedentary activity for each of the 6‐days of measurement were evident with higher tertiles of percent body fat (30–35%, >35% fat) (P < 0.05), but not across all increasing tertiles of BMI (5th to 85th, 85th to 95th, and >95th percentiles). The increase in sedentary activity was observed on weekdays, but not on weekends for percent body fat tertiles. In the cohort of girls measured in both 6th and 8th grades, the mean cross‐sectional coefficient estimates were significant for percent body fat, but not BMI for sedentary and light activities. Adolescent girls from the 6th to 8th grade are shifting their time from light to more sedentary activity as measured by accelerometers. In addition, the increase in sedentary activity is not associated with an adverse effect on BMI or percent body fat. The eventual impact of this shift to a more sedentary lifestyle on body composition and other outcomes needs to be evaluated further.     

Stability of the Association between Birth Weight and Childhood Overweight during the Development of the Obesity Epidemic

Objective: To assess whether changes in the birth weight distribution or changes in the association of birth weight with the later risk of childhood overweight have contributed to the development of the obesity epidemic. Research Methods and Procedures: A Danish population‐based cohort study of 124,615 girls and 128,346 boys (ages 6 to 13 years), born between 1936 and 1983, were studied. Birth weight and annual measurements of height and weight were obtained from school health records. Overweight was defined by BMI in relation to internationally accepted criteria. The relative risk of being overweight by birth weight was calculated separately for each age, sex, and time period. Results: The birth weight distribution remained relatively stable over time. Compared with children with a birth weight of 3.0 to 3.5 kg, the risk of overweight increased consistently with each increase in birth weight category among girls and boys and at all ages between 6 and 13 years. Furthermore, the association between birth weight and increased risk of overweight in childhood remained stable across a 48‐year period. Discussion: The increase in the prevalence of overweight could not be explained by time trends in the distribution of birth weight or by changes in the association between birth weight and the later risk of overweight over time. This implies that, unless the prenatal environment influences the later risk of overweight without increasing birth weight, the environmental influences contributing to the obesity epidemic in children of school age operate in the early postnatal period.