The influence of body mass index on long-term fitness from physical education in adolescent girls

Background: Physical education (PE) can improve physical fitness; however, little research has evaluated PE's long‐term influence. The purpose is to determine PE's longitudinal effects on fitness in a group of adolescent girls and to determine whether body mass index (BMI) status influenced any potential effects. Methods: Participants were enrolled in daily PE throughout their ninth grade. Data were collected at baseline and at the end of 9th, 10th, and 11th grades. BMI (kg/m²) was classified into Centers for Disease Control and Prevention percentiles. Fitness was estimated from a 3‐stage step test (change in exercise heart rate (HR) indicated improved fitness) and analyzed using repeated measures general linear modeling with adjustments for baseline BMI, baseline age, ethnicity, intervention status, and moderate‐to‐vigorous physical activity outside PE. Results: Complete data were available for 131 girls (61% of sample) who were predominantly African American, 13.8 ± 0.4 years, mean BMI 24.7 ± 6.1 kg/m² at the ninth‐grade baseline. Overall, stage 1 HR (bpm) decreased from baseline to 9th grade (?5.5 ± 1.3, p < 0.0001), baseline to 10th grade (?7.2 ± 1.4, p < 0.0001), and baseline to 11th grade (?7.0 ± 1.5, p < 0.0001). Change differed by BMI status; fitness improvement was significant for normal and overweight, but not obese girls. After 2 years, change in stage 1 HR (bpm) was significantly different between BMI categories: normal‐weight girls versus obese girls (?10.0 ± 3.2, p = 0.002) and overweight girls versus obese girls (?9.3 ± 3.9, p = 0.02). Conclusion: Fitness differences by BMI exist after a PE program in adolescent girls: fitness improved and was maintained in normal‐weight and overweight girls, whereby obese girls had no improvement in fitness.     

2型糖尿病患者体重指数与死亡风险的前瞻性研究

  目的  探讨体重指数（body mass index,BMI）与2型糖尿病患者全死因死亡风险的关联。  方法  研究对象为江苏省苏南、苏北地区纳入国家基本公共卫生服务管理的17 638名2型糖尿病患者,应用Cox比例风险回归模型计算基线时不同BMI组人群在随访期间的全死因死亡风险（hazard ratio,HR）值及95%置信区间（confidence interval,CI）。  结果  研究对象累计随访77 451人年,平均随访4.39年,随访期间共死亡1 274人,低体重组BMI < 18.5 kg/m2、正常体重组（18.5 kg/m2 ≤ BMI < 24.0 kg/m2）、超重组（24.0 kg/m2 ≤ BMI < 28.0 kg/m2）、肥胖组（BMI ≥ 28.0 kg/m2）死亡人数分别为39人、575人、484人和176人,相应的死亡率分别为15.6%、9.5%、6.2%、5.1%。调整混杂因素后,以正常体重组为参照,低体重组、超重组、肥胖组死亡风险的HR值（95%CI）分别为1.66（95%CI:1.20~2.30）,0.68（95%CI:0.61~0.77）,0.58（95%CI:0.48~0.68）。  结论  在2型糖尿病患者中,与正常体重人群相比,低体重人群的全死因死亡风险最高,超重和肥胖人群的死亡风险较低,超重和肥胖可以降低2型糖尿病患者死亡风险。     

Carbohydrate craving in obese people: Suppression by treatments affecting serotoninergic transmission

We examined the existence of carbohydrate cravings, and the effects on such cravings of treatments that enhance serotonin release, among 24 obese subjects who claimed to have excessive appetites for carbohydrates. Subjects living in a college dormitory for four weeks were given three fixed meals daily and allowed to choose at will among five protein-rich or five carbohydrate-rich isocaloric snack foods, provided via a vending machine. For two weeks, they received no treatment (study 1) or a placebo (study 2); for the next two weeks, they received placebo, d-1 fenfluramine or 1-tryptophan. All but one of the subjects exhibited a marked preference for carbohydrate-rich over protein-rich snacks during the first two weeks of the study. The average daily intake of carbohydrate-rich snacks was 4.1 ± 0.4 and of protein-rich snacks 0.8 ± 0.3. Seventeen of the subjects failed to consume any protein snacks on most days during the baseline or test periods, thus it was not possible for us to examine the effect of test treatments on protein snack intake. Fenfluramine administration significantly reduced carbohydrate snacking in six of nine test subjects, as well as in the group as a whole (2.4 ± 0.6 snacks/day vs 4.2 ± 0.6 during the two-week baseline period). Tryptophan significantly diminished carbohydrate intake in three of the eight treated subjects, and increased it in one subject; it did not significantly modify snacking patterns in the group as a whole. Placebo administration did not affect carbohydrate intake in any of the seven test subjects. These observations show that some obese people do consume carbohydrate-rich snacks frequently and preferentially, and that this behavior can sometimes be diminished by treatments thought to enhance serotonin's release (fenfluramine) or synthesis (tryptophan).     

Association of energy intake and macronutrient composition with overweight and obesity in malay women from klang valley

This cross-sectional study investigates the association between energy intake and macronutrient composition of the diet with overweight and obesity among Malaysian women. One hundred and fifteen adult Malay women aged 20 to 59 years (mean age 37.2±7.6 years) were interviewed. Dietary intake was assessed using the food history method. Body weight status was assessed using weight, height, waist circumference and fat percentage measurements. When energy intake was assessed for accuracy, only 41% of the subjects (n=47) were normal energy reporters. Among the normal energy reporters, 55% were of normal weight whereas 32% and 13% were overweight and obese. Mean energy intake for normal weight, overweight and obese subjects was 1685±199 kcal/day, 1810±166 kcal/day and 2119±222 kcal/day, respectively. Energy intake increased with body mass index (BMI) category. Among the overweight and obese, energy intake was respectively higher by 125 kcal/day and 434 kcal/day as compared to their normal weight counterparts (p< 0.001). There was also a significant, moderate and positive correlation between energy intake and BMI (r=0.635), waist circumference (r=0.545), and body fat percentage (r=0.534). When macronutrient composition of diet was analysed (% energy and g/1000 kcal), there was no significant difference in carbohydrate, protein or fat intake between the obese, overweight and normal weight subjects. There was also no significant correlation between macronutrient composition of the diet and body weight status. Based on these findings, we conclude that the subjects' body weight status is likely to be influenced by energy intake rather than the macronutrient composition of the diet.     

Dietary factors and body mass index in a group of Iranian adolescents: Tehran lipid and glucose study--2

OBJECTIVE: To study the prevalence of overweight and obesity in an adolescent population in Tehran and to determine possible association with energy and nutrient intake and distribution of energy over the day. METHOD: A cross-sectional study on 177 boys and 244 girls between 10-19 years old was performed. Overweight and obesity were defined by using recommended body mass index (BMI) cut-off values for adolescents. Total energy intake, percent of energy derived from protein, carbohydrate and fat and percent of energy supplied by each meal and snack were assessed by means of two 24-hour dietary recalls. RESULTS: Prevalence of overweight and obesity was 10.7 and 5.1 in boys and 18.4 and 2.8 in girls, respectively. The composition of diet was not different between overweight/obese and normal weight subjects. BMI was related with breakfast energy percentage in girls (r = -0.18, p < 0.01), with total energy intake in boys (r = 0.23, p < 0.01), and with lunch energy percentage in both sexes. In boys (r = 0.16, p < 0.05) and in girls (r = 0.22, p < 0.01). CONCLUSION: High prevalence of overweight and obesity among adolescents was seen. In boys some relationship between total energy intake, distribution of energy over the day and BMI was seen. In girls BMI was only related with distribution of energy over the day.     

Serum homocysteine,B12 and folic acid concentration in Thai overweight and obese subjects

This study investigated levels of serum homocysteine, vitamin B12, folic acid, vitamin B6 and vitamin C, in 37 male and 112 female overweight and obese Thai volunteers (body mass index; BMI > or = 25.00), and 23 male and 90 female normal-weight Thai volunteers, who came for a physical check-up at the Out-patient Department, General Practice Section, Rajvithi Hospital, Bangkok from March to October of 2000. Data included anthropometric measurements and waist/hip ratios. All anthropometric variables, except height, were significantly higher for the overweight subjects than for the normal subjects. Statistically significantly higher levels of serum homocysteine were found in the overweight subjects. Serum homocysteine concentrations in overweight and obese males were significantly higher than in overweight and obese females. Serum folic acid and vitamin C in the overweight and obese were found to be statistically significantly lower than in the control subjects. No statistically significant difference in vitamin B12 was found in the overweight and obese subjects compared with the normal control subjects. The medians of serum folic acid and vitamin C concentrations for the overweight and obese males were significantly lower than those of the overweight and obese females. A negative correlation was found between serum folic acid and homocysteine concentrations in all overweight and obese subjects. A significant negative correlation between serum folic acid and vitamin B6 was observed in both male and female overweight and obese subjects. The results of the investigation suggest that homocysteine levels in overweight and obese subjects seem to be caused by insufficient dietary folic acid intake and probably not by B12 deficiency.     

Correlation between attention deficit hyperactivity disorder and sugar consumption, quality of diet, and dietary behavior in school children

This study investigated the correlation between consumption of sugar intake by fifth grade students in primary schools and development of Attention Deficit Hyperactivity Disorder (ADHD). A total of 107 students participated, and eight boys and one girl (8.4% of the total) categorized as high risk for ADHD according to diagnostic criteria. There were significant differences in the occupations and drinking habits of the respondents'' fathers between the normal group and risk group. In a comparison of students'' nutrition intake status with daily nutrition intake standards for Koreans, students consumed twice as much protein as the recommended level, whereas their calcium intake was only 60% of the recommended DRI (dietary reference intake). Regarding intake volume of vitamin C, the normal group posted 143.9% of the recommended DRI, whereas the risk group showed only 65.5% of the recommended DRI. In terms of simple sugar intake from snacks, students in the normal group consumed 58.4 g while the risk group consumed 50.2 g. These levels constituted 12.5% of their total daily volume of sugar intake from snacks, which is higher than the 10% standard recommended by the WHO. In conclusion, children who consumed less sugar from fruit snacks or whose vitamin C intake was less than RI was at increased risks for ADHD (P < 0.05). However, no significant association was observed between total volume of simple sugar intake from snacks and ADHD development.     

Distribution and determinants of body mass index of non-smoking adults in Delhi, India

Data on height and weight of 3,428 non-smoking healthy adult subjects, obtained during an earlier community-based study in Delhi, India, on chronic respiratory morbidity due to ambient air pollution was analyzed to study the distribution of body mass index (BMI) and its determinants among adults in Delhi. The sample was drawn by systematic sampling from rural and urban areas of Delhi. In urban areas, the sampling frame was restricted to areas around air quality-monitoring stations. However, the areas were spread across the city and reflected wide economic spectrum. Subjects were classified as underweight, normal, overweight, and obese as per the criteria of the World Health Organization for BMI. The mean BMI of the entire sample was 22.14 +/- 4.61. It was higher among females, urban residents, and the higher-income group. Overall, 49.7% of the 3,428 subjects had a normal nutritional status, 24.8% were underweight, 19.4% overweight, and 6.1% obese. The prevalence of underweight was higher in rural areas (38.5%) and among the lower-income group (39.9%), while overweight and obesity were more common in urban residents (22.7% and 7.5% respectively), among females (21.7% and 7.7%), and the higher-income group (31.8% and 11%) (p < 0.05). The adjusted odds for underweight were 2.02 for rural subjects and 4.00 for the lower-income group. For overweight or obesity, odds were 5.6 for the higher-income group, 3.62 for urban residents, and 2.5 for females. It was concluded that problems of both underweight and overweight and obesity exist among the adults of Delhi. While females, residents of urban areas, and economically-better-off were more likely to be overweight or obese, residents of rural areas and those from lower-income groups were more likely to be underweight.     

Exercise, body mass index, caloric intake, and cardiovascular mortality

BACKGROUND: The association of physical inactivity and elevated body mass index (BMI) with cardiovascular disease (CVD) risk is well established. The relationship of dietary caloric intake and CVD risk is less certain. METHODS: The epidemiologic follow-up of the First National Health and Nutrition Examination Survey (1971-1992) was examined to determine the relationship of caloric intake, BMI, and physical activity to CVD mortality. Of 14,407 participants, 9790 subjects aged 25 to 74 years met inclusion criteria. The CVD mortality rate was the outcome. RESULTS: During the 17 years of follow-up, there were 3183 deaths, 1531 of which were due to CVD (9.11/1000 person-years). People with relatively less physical activity, lower caloric intake, and who were overweight (BMI 25 to 29.9 kg/m(2)) and obese (BMI > or =30 kg/m(2)) had a less favorable baseline CVD risk profile than did those who were more active and of normal weight and had greater caloric intake. Age- and race/ethnicity-adjusted CVD mortality rates were highest among those with the least physical activity and lowest caloric intake, and who were overweight or obese. Moreover, subjects of normal weight who exercised most were more likely to have high caloric intake and lower CVD mortality (5.9 vs 14.7 per 1000 person-years, p =0.01) than subjects who were obese and exercised least. In Cox regression analysis, controlling for relevant CVD risk factors, least physical activity was independently associated with increased CVD mortality (hazard ratio=1.32, 95% confidence interval [CI]=1.13-1.53); and obesity was associated with increased CVD mortality (hazard ratio=1.24, 95% CI=1.06-1.44). Although highest dietary caloric intake was associated with reduced CVD mortality (hazard ratio=0.83, 95% CI=0.74-0.93), after adjusting for physical activity and BMI, there was no significant association of highest caloric intake with CVD mortality (hazard ratio=0.91, 95% CI=0.81-1.01). CONCLUSIONS: In this large general population sample, lower levels of physical activity and obesity were independently associated with decreased CVD survival. Moreover, when BMI, physical activity, and other relevant characteristics were taken into account, caloric intake was not related to CVD mortality.     

Differences in eating and activity markers among normal weight, overweight, and obese rural women.

PURPOSE: The purpose of this study was to examine differences in healthy eating and physical activity behaviors and associated biomarkers among normal weight (body mass index [BMI] < 25), overweight (BMI 25-29.9), and obese (BMI > or = 30) rural women. METHODS: Random digit dialing was used to recruit 225 rural women (57.9 +/- 5.6 years). Measures of healthy eating and physical activity were completed on the computer during individual sessions at the rural sites. Research nurses then assessed a battery of biomarkers of activity and eating, including blood lipids, blood pressure, cardiorespiratory fitness (VO(2max)), and resting heart rate. RESULTS: Major findings were differences across weight categories in daily calories consumed and expended, daily fruit servings, daily meat group servings, high-density lipoprotein cholesterol, vital signs, and cardiorespiratory fitness. The obese women both consumed and expended significantly more calories daily than those in the other two weight groups. Obese women consumed significantly fewer fruit group servings than both the normal weight and overweight women. Obese women consumed significantly more meat group servings than overweight women. There also were significant differences in systolic blood pressure, diastolic blood pressure, resting heart rate, high-density lipoprotein cholesterol, and cardiorespiratory fitness across the three weight groups. CONCLUSIONS: This study provides evidence of major differences in some eating and activity behaviors and biomarkers across BMI groups. Major differences exist between the normal weight and overweight group as compared to the obese group.     

Recognition of body image and food behavior factors among middle school students in San Francisco area

The purpose of this study was to determine the recognition of body image and food behavior factors according to the BMI. The subjects of this study were 242 7th grade students resided in San Francisco area. The degree of recognition for self-estimated physique of subjects by gender and by race showed no significant differences by gender but significant differences by race, showing that 20.0% was considered as underweight in Asian and 7.5% was considered as underweight in White students. This showed the same tendency as actual physique status (BMI). Also, the ratio of being recognized as more than overweight was 17.3% in Asian, 23.3% in Hispanic, and 13.4% in White students. In case of female students, the ratio of dieting experience was 63.3%, and 49.3% of White students and 63.3% of Hispanic students experienced dieting. In case of students answered not healthy, their body weight were significantly higher than those answered as healthy, and the BMI was also over 19, showing significant differences. Thus cases that answered as not healthy had greater body weight and BMI. Also it showed that frequent dieting experience is related to higher height and weight. The analysis of food behavior factors perceived by body shape showed that the group perceived itself as overweight consumed more ''fast food'' but had low scores in ''vegetables'' intake, with frequent intake of ''soda'' and tendency to ''overeat''. Also, the tendency for ''balanced life'' was significantly lower and for skipping breakfast was significantly higher, suggesting problematic food behavior.     

Association between fruit juice consumption and self‐reported body mass index among adult Canadians

Background: The prevalence of obesity and being overweight is rising among adult Canadians and diet is recognised as one of the main causes of obesity. The consumption of fruit and vegetables is shown to be protective against obesity and being overweight but little is known about the association of fruit juice consumption and obesity and being overweight. The present study aimed to investigate the association between fruit juice consumption and self‐reported body mass index (BMI) among adult Canadians. Methods: This analysis is based on the Canadian Community Health Survey, Cycle 3.1. A regression method was used to assess the association of fruit juice consumption with self‐reported BMI in 18–64‐year‐old Canadians who had been adjusted for sex, age, total household income, education, self‐rated health, and daily energy expenditure. Because the analysis is based on a cross‐sectional dataset, it does not imply a cause and effect relationship. Results: Almost 38.6% of adult Canadians reported a fruit juice intake of 0.5–1.4 times per day and 18.2% consumed fruit juice more than 1.5 times per day. Participants with normal weight were likely to consume more fruit juice than obese individuals. Regression analysis showed a negative association between fruit juice consumption and BMI after adjusting for age, sex, education, marital status, income, total fruit and vegetable intake, daily energy expenditure, and self‐rated health. On average, for each daily serving of fruit juice, a ?0.22 unit (95% confidence interval = ?0.33 to ?0.11) decrease in BMI was observed. Conclusions: The results obtained showed a moderate negative association between fruit juice intake and BMI, which may suggest that a moderate daily consumption of fruit juice is associated with normal weight status.     

Pictogram use was validated for estimating individual's body mass index

ObjectiveWe designed this study to assess the validity and reliability of pictogram for estimating body mass index (BMI).Study Design and SettingParticipants of Golestan cohort study during 2000–2004 were recruited in this study. Demographic and anthropometric information (weight, height, and BMI) were collected on all participants. A set of drawings (pictogram) ranging from very lean to obese were used to assess the individual's perception of their body size. Sensitivity and specificity of each pictogram score were calculated and cutoff points were determined using sensitivity/specificity plots. We used receiver operating characteristic curves to assess the validity of pictogram scores.ResultsOf the 15,437 subjects enrolled in the study, 6,574 (42.6%) were males and 8,863 (57.4%) were females. Their mean ± standard deviation age was 52.58 ± 9.28 years. Pictogram scores 1, 2, and 3 were assigned to normal participants; pictogram score 4 was selected by overweight subjects, and finally, pictogram scores equal or higher than 5 were selected by obese ones (area under curve: 0.83–0.85).ConclusionAccording to our results, pictogram is a valid measure for discriminating obese or overweight from normal individuals, and for distinguishing obese from overweight or normal individuals. So it can be concluded that body image pictogram is valid for discriminating normal and obese individuals.     

Nutritional Status and Serum Levels of Micronutrients in an Elderly Group Who Participate in the Program for Complementary Food in Older People (PACAM) from the Metropolitan Region,Santiago de Chile

The increase in the Chilean elderly population has promoted public policies to favor an adequate nutrition in later life. This study evaluated the nutritional status, micronutrients intake and serum micronutrients levels of an elderly group beneficiary of the PACAM from the Metropolitan Region, Santiago de Chile. Anthropometric and dietary survey (24 h food recalls) were assessed in 182 elderly individuals (60 and 80 years old). Blood serum collection was used to measure the micronutrient status. The sample was comprised by 12.6%, 46.1%, 28.0% and 13.2% of underweight, normal weight, overweight and obese subjects, respectively. Women presented 11% of underweight, 45% of normal weight and 44% of overweight and obese, while men—18%, 50% and 32%, respectively. Only the 63% of the elderlies consumed PACAM foods, reaching average daily intakes below (50%) the recommended daily serving. Serum deficiencies of 25-hydroxyvitamin D (88%), vitamin B₁₂ (33%) and calcium (36%) were observed, being the highest ones in the PACAM foods women (60–75 years old). Chilean elderlies presented mainly a normal weight; however, an important proportion of overweight/obese subjects was observed. Although PACAM foods consumption significantly increased the micronutrient intake, it was not enough to ensure an adequate serum micronutrient levels in the elderly.     

A pilot study to investigate the effect of plate size on meal energy intake in normal weight and overweight/obese women

Background: Smaller plates are often recommended as a strategy for controlling energy intake; however, the effect of plate size on meal energy intake in normal weight compared to overweight or obese individuals is not known. The present study aimed to investigate this further. Methods: Ten normal weight [mean (SD) body mass index, 21.7 (2.0) kg m^?2] and 10 overweight or obese [31.7 (3.6) kg m^?2] women attended a metabolic laboratory on two separate days for lunch. In this cross‐over study, subjects were randomly assigned to eat lunch using either a small (21.6 cm) or a large (27.4 cm) plate. Each subject self‐served spaghetti mixed with tomato sauce from an individual serving bowl onto the assigned plate, and ate until satisfied. The meal was consumed alone at a private table. During the second study day, each subject underwent the same procedure but used the alternate size plate. The amount eaten and energy consumed were calculated and a mixed effects analysis of variance model was used to compare energy intakes. Results: Energy intakes using the small and large plate were 1356 (515) and 1365 (393) kJ, respectively, in normal weight subjects and 1314 (632) and 1226 (431) kJ, respectively, in overweight/obese subjects. Neither plate size, nor plate size by weight status significantly affected meal energy intake. There was no plate size by weight status effect on ratings of palatability, hunger, satiety, fullness or prospective consumption. Conclusions: Plate size did not affect energy intake from a single meal in either the normal weight or overweight/obese subjects.     

Economic burden of cardiovascular disease associated with excess body weight in U.S. adults

BACKGROUND: Excess body weight (EBW), which continues to become more prevalent, is a clear contributor to cardiovascular disease (CVD), the leading cause of death and disability among U.S. adults. Information on the economic impact of CVD associated with EBW is lacking, however. OBJECTIVE: To estimate the direct medical costs of CVD associated with EBW. METHODS: We conducted a population-based analysis of direct medical costs by linking the 1995 National Health Interview Survey and the 1996 Medical Expenditure Panel Survey. The study subjects are adults (aged > or =25 years, excluding pregnant women) in the non-institutionalized, civilian population in 1996. RESULTS: The prevalence of CVD among people in the normal weight (body mass index [BMI] > or =18.5 to <25), overweight (BMI > or =25 to <30), and obese (BMI > or =30) groups was 20%, 28%, and 39%, respectively. There were 12.95 million CVD cases among overweight people, more than 25% of which was associated with overweight. There were 9.3 million CVD cases among obese people, of which more than 45% was associated with obesity. This extra disease burden led to $22.17 billion in direct medical costs in 1996 ($31 billion in 2001 dollars, 17% of the total direct medical cost of treating CVD). CONCLUSIONS: The strong positive association between EBW and CVD, and the significant economic impact of EBW-associated CVD demonstrate the need to prevent EBW among U.S. adults.     

成都地区不同BMI健康男性的能量代谢研究

目的 研究四川省成都市不同体质指数(Body Mass Index, BMI)健康男性的能量代谢情况及预测公式估计值与测量值之间的差异。方法 选取四川成都地区的健康男性成年人,并以BMI为依据进行分组,采用不同预测公式计算能量代谢情况,同时采用间接测热法确定研究对象能量代谢水平,比较不同组间能量代谢水平及预测值与实测值的差异,分析身高、体重等因素的与能量代谢的相关程度。结果 本研究共招募研究对象33名,其中,正常体重组12名,超重组11名,肥胖组10名。正常组的基础能量消耗(basal energy expenditure, BEE)、静息能量消耗(resting energy expenditure, REE)均低于超重和肥胖组,但经体重校正后,基础代谢率(basal metabolism rate, BMR)、静息代谢率(resting metabolic rate, RMR)由高到低依次为:正常组>超重组>肥胖组; Lazzer 公式能较好地反映能量消耗,准确率为84.85%,其次是Schofield 和WHO/FAO/UNU公式,准确率均为81.82%; 身高、体重、BMI、腰围和体表面积与BEE呈正相关关系,相关程度最高的是体重与体表面积。结论 BMI正常人群的能量代谢率明显高于超重与肥胖人群,其中体重、体表面积与基础能量消耗呈正相关; Lazzer公式能较好地预测本地区的基础能量消耗。     

Combined effects of prepregnancy body mass index and weight gain during pregnancy on the risk of preterm delivery

BACKGROUND: The association between excessive gestational weight gain and preterm delivery is unclear, as is the association between low gestational weight gain and preterm delivery among overweight and obese women. METHODS: Using data from the Pregnancy Risk Assessment Monitoring System in 21 states, we estimated the risk of very (20-31 weeks) and moderately (32-36 weeks) preterm delivery associated with a combination of prepregnancy body mass index (BMI) and gestational weight gain among 113,019 women who delivered a singleton infant during 1996-2001. We categorized average weight gain (kilograms per week) as very low (<0.12), low (0.12-0.22), moderate (0.23-0.68), high (0.69-0.79), or very high (>0.79). We categorized prepregnancy BMI (kg/m) as underweight (<19.8), normal (19.8-26.0), overweight (26.1-28.9), obese (29.0-34.9), or very obese (>or=35.0). We examined associations for all women and for all women with no complications adjusting for covariates. RESULTS: There was a strong association between very low weight gain and very preterm delivery that varied by prepregnancy BMI, with the strongest association among underweight women (adjusted odds ratio = 9.8; 95% confidence interval = 7.0-13.8) and the weakest among very obese women (2.3; 1.8-3.1). Very low weight gain was not associated with moderately preterm delivery for overweight or obese women. Women with very high weight gain had approximately twice the odds of very preterm delivery, regardless of prepregnancy BMI. CONCLUSIONS: This study supports concerns about very low weight gain during pregnancy, even among overweight and obese women, and also suggests that high weight gain, regardless of prepregnancy BMI, deserves further investigation.     

Social class, family, and life-style factors associated with overweight and obesity among adults in Peruvian cities

BACKGROUND: Overweight and obesity have reached epidemic proportions in Latin America. OBJECTIVE: The purpose of this study was to explore social and behavioral factors associated with obesity in Peruvian cities. DESIGN: Between 1998 and 2000 health examination surveys were conducted among adults in 1176 families identified in six cities. Stratified by social class, multistaged random sampling was used. Using body mass index (weight (kg)/height (m)(2)), men and women were classified into normal weight (BMI <25), overweight (BMI 25-29), or obese (BMI > or =30); abdominal circumference (> or =94 cm in men and > or =84 cm in women) further identified morbidity risk. Several demographic, social, and behavioral variables were collected following standardized procedures. RESULTS: Adjusting for age, 37% of women were categorized as normal weight, 40% overweight, and 23% obese; corresponding figures for men were 40, 44, and 16%. More developed cities, e.g., Lima, Arequipa, and Ica, had the largest prevalence of overweight and obesity for both men and women. Adjusted logistic models showed that BMI > or =25 was positively correlated with age; whereas, education was negatively associated, only among women. Other significant associated factors of overweight included city of residence, television viewing > or =4 h daily in women, and underestimation of body weight status. CONCLUSIONS: The study showed elevated rates of overweight across the income level spectrum. Factors such as urban development stage, income, education, and gender posed differential relationships with the risk of overweight and must be considered in designing future public health interventions. Underestimation of body weight status and sedentary behavior may also constitute specific areas of intervention.