Acculturation and overweight-related behaviors among Hispanic immigrants to the US: the National Longitudinal Study of Adolescent Health

Little is known about the factors underlying the striking increase in overweight occurring between first and second generation US immigrants. Using data from the National Longitudinal Study of Adolescent Health, this study addressed two goals. First, we determined which measures of acculturation (defined as the acquisition of dominant cultural norms by members of a non-dominant group) were important. Second, we determined how the acculturation process affected differences in overweight and its proximate determinants (e.g., physical activity, diet, and smoking) as immigrants acculturated to American society. In addition, we sought to elucidate the role of underlying structural factors (e.g., family income and crime) and acculturation factors (e.g., language spoken at home and proportion of foreign-born neighbors) in generation differences in overweight. Results showed clear structural and acculturation differences between foreign and US-born immigrants to the US. Foreign-born immigrants were more likely to have lower family income and maternal education, and to live in areas of higher immigrant density and greater linguistic isolation. In addition, results suggested rapid acculturation of overweight-related behaviors, such as diet, smoking, and inactivity, in US-born relative to foreign-born immigrants. Multivariate analysis indicated that longer US residence was associated with increased overweight among Puerto Ricans and Cubans. Predicted probabilities showed that controlling for acculturation and proximate factors increased overweight among foreign-born adolescents, but had minimal impact for US-born adolescents. Thus, without the beneficial pattern of: acculturation factors, diet, and physical activity, first generation Hispanic adolescents would have higher overweight prevalence. We found important generation differences in structural, acculturation, and proximate overweight determinants. These lifestyle differences between foreign- and US-born Hispanic adolescent immigrants are likely to underlie the striking increase in overweight prevalence between first and subsequent generation of US residence.     

中国八省成人膳食脂肪摄入状况及变化趋势分析——中国八省实例研究

目的 :　探讨 1 991～ 1 997年中国成人膳食脂肪摄入量、脂肪食物来源及其组成变化趋势。方法 :　利用“中国居民健康与营养调查”的资料 ,选取 1 991、1 993和 1 997年调查中 1 8～ 6 5岁健康成人作为研究对象 ,以成人膳食脂肪摄入量、脂肪供能比、脂肪食物来源和脂肪酸组成作为评价居民脂肪摄入状况的指标 ,以 SAS软件对数据库资料进行统计分析。结果及结论 :　 1 991～1 997年在城市、郊区和县城三类地区成人脂肪摄入量增加 ,脂肪提供能量在总能量中所占比例提高 ,城市已达到 3 4 .79%。胆固醇摄入量也呈增加趋势 ,城市居民胆固醇平均摄入水平已达到3 6 1 .5 5 mg/d。植物油脂和动物性食物消费量增加已成为城市居民脂肪摄入提高的主要原因。饱和脂肪酸、单不饱和脂肪酸和多不饱和脂肪酸在总能量中所占比例均呈提高趋势 ,其中以单不饱和脂肪酸增长最快。农村居民膳食脂肪摄入状况稳定在较低的摄入水平。     

Patterns of overweight,inactivity, and snacking in Chinese children

OBJECTIVE: To examine patterns of inactivity and snacking and their relationship with overweight status in Chinese children. RESEARCH METHODS AND PROCEDURES: The study population was drawn from the 1997 China Health National Survey (1385 children, ages 6 to 11 years), conducted with a representative sample from nine provinces. The 2000 Centers for Disease Control and Prevention BMI charts were used to calculate "at risk of overweight" as those above the 85th percentile. Three days of 24-hour recall dietary data and detailed questions on physical activity and inactivity for the previous 7 days were used. RESULTS: 9.4% of the children were classified as overweight. Weekly mean and range of hours spent watching television/videos, playing video games, studying, and in inactive transport were 5.1 (0 to 35), 0.3 (0 to 10), 4.7 (0 to 60), and 0.14 (0 to 4.2), respectively. Television/video viewing and studying did not differ in any meaningful manner between overweight and normal weight children. Snacking is inconsequential in China, comprising only 0.9% of energy intake. DISCUSSION: Chinese children are less overweight, less inactive, and less likely to ingest calories as snacks than children in the U.S. The absence of impact of these measures of inactivity, which are below an hour per day for the average Chinese child, indicate the possible value of limiting television viewing and other types of inactivity in other countries. Modern Western-style television programming and advertising started to come to China after 1997; therefore, extensive changes in television viewing patterns are expected to emerge.     

Estimating body fat from anthropometry and isotopic dilution: a four-country comparison

OBJECTIVE: The goal was to assess the ability of BMI to predict body fat (BF) among youths in four countries and identify the degree to which additional anthropometric measures improve this prediction. BMI is widely recommended as an indicator of overweight. However, whether BMI adequately estimates BF and has the same meaning in different ethnic groups and youths has been questioned. RESEARCH METHODS AND PROCEDURES: Data come from 456 Filipino, Chinese, Russian, and black South African youths, 6 to 16 years old. Percentage BF and fat mass index (FMI) were estimated by the deuterium dilution method. Skinfold thicknesses (triceps, subscapular, and suprailiac) and weight and height measures were collected. Percentage BF was regressed first on BMI and age and then with the addition of the skinfold measures. Linear models were run separately by country and sex. The models were repeated with FMI as the outcome. RESULTS: The R2 values from the percentage BF models ranged from 0.13 to 0.69 in the first models to 0.38 to 0.81 in the full models. The values were lowest among Russian males > or = 13 years and Russian females > or = 13 years of age in the reduced and full models, respectively, and were highest among Chinese females. Using FMI as the outcome did not meaningfully change the results. DISCUSSION: The ability of BMI to adequately predict BF and the additional predictivity of anthropometric measures varied widely across the samples, making its uniform use as a proxy for BF in youths from different countries questionable.     

The increasing prevalence of snacking among US children from 1977 to 1996

OBJECTIVES: To determine snacking trends and changes in nutrient contribution of snacking over time. STUDY DESIGN: Nationally representative data from the 1977-78 Nationwide Food Consumption Survey (NFCS77), 1989-91 Continuing Survey of Food Intake by Individuals (CSFII89), and 1994-96 (CSFII96) were used. The sample consisted of 21,236 individuals aged 2 to 18 years. METHODS: For each survey year, mean numbers of snacks consumed, mean grams consumed per snack, and mean energy intake from snacks were computed, as was contribution of snacking to total energy intake and fat intake. Snacking was self-defined, and a snacking occasion consisted of all snack foods consumed during a 15-minute period. Differences in means between age groups and across survey years were compared. RESULTS: The prevalence of snacking increased in all age groups. The average size of snacks and energy per snack remained relatively constant; however, the number of snacking occasions increased significantly, therefore increasing the average daily energy from snacks. Compared with non-snack eating occasions, the nutrient contribution of snacks decreased in calcium density and increased in energy density and proportion of energy from fat. CONCLUSION: Snacking is extremely prevalent in our society. Healthy snack food choices should be emphasized over high-energy density convenience snacks for children.     

The nutrition transition and obesity in the developing world

Changes in diet and activity patterns are fueling the obesity epidemic. These rapid changes in the levels and composition of dietary and activity/inactivity patterns in transitional societies are related to a number of socioeconomic and demographic changes. Using data mainly from large nationally representative and nationwide surveys, such as the 1989, 1991, 1993 and 1997 China Health and Nutrition Surveys, in combination with comparative analysis across the regions of the world, we examine these factors. First, we show the shifts in diet and activity are consistent with the rapid changes in child and adult obesity and in some cases have been causally linked. We then provide a few examples of the rapid changes in the structure of diet and activity, in particular associated with increased income. Cross-country and in-depth analysis of the China study are used to explore these relationships. People living in urban areas consume diets distinctly different from those of their rural counterparts. One of the more profound effects is the accelerated change in the structure of diet, only partially explained by economic factors. A second is the emergence of a large proportion of families with both currently malnourished and overweight members as is shown by comparative analysis of a number of Asian and Latin American countries.     

Significant increase in young adults' snacking between 1977-1978 and 1994-1996 represents a cause for concern!

BACKGROUND: Studies on children and adolescents suggest a large increase in the role of snacking; however, little is know about changes in the snacking behavior of young adults. METHODS: USDA's nationally representative surveys from 1977-1978 to 1994-1996 are used to study snacking trends among 8,493 persons 19-29 years old. RESULTS: Snacking prevalence increased from 77 to 84% between 1977-1978 and 1994-1996. The nutritional contribution of snacks to total daily energy intake went from 20 to 23%, primarily because energy consumed per snacking occasion increased by 26% and the number of snacks per day increased 14%. The mean daily caloric density (calorie per gram of food) of snacks increased from 1.05 to 1.32 calories. The energy contribution of high-fat desserts to the total calories from snacking decreased (22 to 14%), however, this food group remained the most important source of energy. The energy contribution of high-fat salty snacks doubled. Sweetened and alcoholic beverages remained important energy contributors. CONCLUSION: This large increase in total energy and energy density of snacks among young adults in the United States may be contributing to our obesity epidemic.     

盐酸放线瑞香宁的紫外二阶导数光谱法测定及在兔体内的药代动力学

盐酸放线瑞香宁(actinodaphine-HCl)系从莲叶桐科青藤属植物黑吹风(Illigera khasiana C.B Clarke)中分离提取而得的有效成分,结构式如图1。药理试验证明有解热、镇痛、解痉等作用。本文报告用紫外二阶导数光谱法研究盐酸放线瑞香宁在兔体内的药代动力学结果。家兔4只,体重2.8±0.6kg。盐酸放线瑞香宁由本所植化室提供。氯仿、乙醇均为A.R。Perkin-Elmer型紫外—可见光分光光度计系美国产品。