Influence of exclusive resistance training on body composition and cardiovascular risk factors in overweight or obese children: a systematic review

Objective: Since the last decade, a significant increase in the prevalence of overweight and obesity among children has been reported. Low aerobic fitness and a low compliance with endurance sports in such children are theoretical reasons to favor the use of resistance training in intervention studies, even though positive effects of resistance training on morbidity without accompanying dietary modifications are a matter of debate. In this review we summarize the studies that have shown the isolated effect of resistance training on body composition and cardiovascular risk factors in overweight and obese children. Method: We systematically reviewed interventional studies that exclusively applied resistance training to overweight and obese 3- to 18-year-old children. Outcome measurements were body composition or cardiovascular risk factors. Results: Only six studies passed the inclusion criteria. All studies preferred an individually planned and supervised whole-body resistance training of moderate to submaximal intensity during treatment. The mean compliance was 84%. Four studies reported significant changes in body composition, with an increase in fat free mass and BMI, along with a decrease in fat mass. Three studies analyzed the effect of resistance training on cardiovascular risk factors, and only one study reported a significant decrease in systolic blood pressure. Conclusion: An individually planned and supervised whole-body resistance training of moderate to submaximal intensity in children seems to be safe and tends to show positive effects on body composition. Similar to interventions based on endurance exercise alone or in combination with dietary modifications, the effects on cardiovascular risk factors cannot be substantiated. In consequence, we suggest to substantiate the effect of resistance training on cardiovascular risk factors in overweight and obese children in upcoming randomized controlled trials with high case numbers, applying both resistance training only and resistance training in combination with dietary intervention to get knowledge about whether resistance training alone is effectual in the treatment of overweight and obesity in youth or if a combination of resistance training and dietary interventions is actually needed. Copyright ? 2012 S. Karger GmbH, Freiburg.     

Body Fat Percentile Curves for Korean Children and Adolescents: A Data from the Korea National Health and Nutrition Examination Survey 2009-2010

A valid assessment of obesity in children and adolescents is important due to significant change in body composition during growth. This study aimed to develop percentile curves of body fat and fat free mass using the Lambda, Mu, and Sigma method, and to examine the relationship among body mass index (BMI), fat mass and fat free mass in Korean children and adolescents, using the Korea National Health and Nutrition Examination Survey (KNHANES) 2009-2010. The study subjects were 834 for boys and 745 for girls aged between 10 and 18 yr. Fat mass and fat free mass were measured by dual-energy x-ray absorptiometry. The patterns of development in body fat percentage, fat mass and fat free mass differed for boys and girls, showing a decreased fat mass with an increased fat free mass in boys but gradual increases with age in girls. The considerable proportion of boys and girls with relatively normal fat mass appeared to be misclassified to be at risk of overweight based on the BMI criteria. Therefore, the information on the percentiles of body fat and fat free mass with their patterns would be helpful to complement assessment of overweight and obesity based on BMI for Korean children and adolescents.     

FTO基因rs9939609单核苷酸多态性与新疆哈萨克族超重及肥胖儿童的关联研究

目的 研究体脂量和肥胖症相关基因(fat mass and obesity associated gene,FTO)单核苷酸多态性与新疆哈萨克族学龄儿童超重及肥胖症的关系.方法 应用聚合酶链反应-限制性片段长度多态性的方法,对141例超重及肥胖(病例组)的哈萨克族学龄儿童和138名健康对照儿童FTO基因rs9939609位点进行分析,同时进行血糖、血脂、胰岛素测定.结果 FTO基因rs9939609在病例组和健康对照组中基因型频率分别为:AA型0.071和0.029,AT型0.511和0.428,TT型0.418和0.543,两组AA、AT和TT 3种基因型频率分布差异无统计学意义(x2=5.74,P=0.057),但AA+AT(突变纯合子+突变杂合子)在病例组[0.582(82/141)]明显高于对照组[0.457(63/138)],差异具有统计学意义(x2=4.368,P=0.037);且在两组人群中A等位基因频率差异具有统计学意义(x2=4.772,P=0.029).病例组中AA+AT基因型携带者的血糖水平[(4.88±0.51)mol/L]较TT基因型携带者[(4.68±0.56)mol/L]高,差异具有统计学意义.Logistic回归分析显示,A等位基因是超重及肥胖的独立危险因素(OR=0.527;95%CI:0.319～0.869).结论 体脂量和肥胖症相关基因第1内含子rs9939609多态性和新疆哈萨克族学龄儿童超重及肥胖的发生具有相关性.     

Using cluster heat maps to investigate relationships between body composition and laboratory measurements in HIV-infected and HIV-uninfected children and young adults

Cluster heat maps were used to investigate relationships between body composition, lipid levels, and glucose metabolism in HIV-infected and HIV-uninfected children and young adults using data from a cross-sectional study. Three distinct clusters of participants were identified. One group had lower body fat and higher lipid measures and was mostly HIV infected. The other 2 groups were a mix of HIV-infected and HIV-uninfected participants. Of these, 1 cluster had more participants with higher body fat and insulin resistance, which are risk factors for future cardiovascular disease, and the other had relatively normal measurements on all outcomes.     

<Emphasis Type="Italic">APOA5</Emphasis> gene variation modulates the effects of dietary fat intake on body mass index and obesity risk in the Framingham Heart Study

Diet is an important environmental factor interacting with our genes to modulate the likelihood of developing lipid disorders and, consequently, cardiovascular disease risk. Our objective was to study whether dietary intake modulates the association between APOA5 gene variation and body weight in a large population-based study. Specifically, we have examined the interaction between the APOA5-1131T>C and 56C>G (S19W) polymorphisms and the macronutrient intake (total fat, carbohydrate, and protein) in their relation to the body mass index (BMI) and obesity risk in 1,073 men and 1,207 women participating in the Framingham Offspring Study. We found a consistent and statistically significant interaction between the -1131T>C single-nucleotide polymorphism (SNP; but not the 56C>G) and total fat intake for BMI. This interaction was dose-dependent, and no statistically significant heterogeneity by gender was detected. In subjects homozygous for the -1131T major allele, BMI increased as total fat intake increased. Conversely, this increase was not present in carriers of the -1131C minor allele. Accordingly, we found significant interactions in determining obesity and overweight risks. APOA5-1131C minor allele carriers had a lower obesity risk (OR, 0.61, 95%; CI, 0.39-0.98; P = 0.032) and overweight risk (OR, 0.63, 95%; CI, 0.41-0.96; P = 0.031) compared with TT subjects in the high fat intake group (>or=30% of energy ) but not when fat intake was low (OR, 1.16, 95%; CI, 0.77-1.74; P = 0.47 and OR = 1.15, 95%; CI, 0.77-1.71; P = 0.48) for obesity and overweight, respectively). When specific fatty acid groups were analyzed, monounsaturated fatty acids showed the highest statistical significance for these interactions. In conclusion, the APOA5-1131T>C SNP, which is present in approximately 13% of this population, modulates the effect of fat intake on BMI and obesity risk in both men and women.     

解偶联蛋白3基因启动子区-55（C〉T）多态与中国人静息能量消耗及体脂含量与分布的关系

目的 研究解偶联蛋白3基因（UCP3）启动子区-55（C〉T）多态与中国人静息能量消耗、体脂参数的关系。方法 在300名中国人（正常体重91人，超重／月巴胖209人）中，用聚合酶链反应一限制性片段长度多态性（polymemse chain reaction-restriction fragment length polymorphisms，PCR—RFLP）检测伙巧基因启动子区-55（C〉T）变异，并测定其静息能量消耗、体脂含量及分布。结果 UCP3基因启动子区-55（C〉T）多态基因型频率与肥胖及肥胖类型均无相关。正常体重组1T基因型者静息能量消耗水平显著高于CT及CC基因型者（P〈0．05）；超重／肥胖组各基因型者间比较亦有同样趋势。在超重／肥胖组，TT基因型者FM／FFM值与CT及CC基因型者差异有显著意义（P〈0．01）。结论 UCP3基因启动子区-55（C〉T）多态与中国人静息能量消耗相关，该变异可能通过对静息能量消耗的影响调节机体的能量代谢。     

The influence of obesity on the frequency and distribution of medication

Obesity is a serious health problem in industrialized countries and is associated with a significant increase in total health care costs. Only few data are available about the costs of drug therapies in patients with an increased body weight treated under clinical routine procedures. Such data could support efforts to intensify obesity prevention and treatment programmes in order to reduce comorbidities and costs. We have evaluated body mass index (BMI), diagnosis, and medication in 3360 outpatients (2175 women and 1185 men; mean age: 56.7 +/- 17.5 years). All patients underwent physical examinations, including BMI determination, and provided a detailed record concerning medication. In 1809 patients, the percentage of body fat content was measured with a bioimpedance method (OMRON BF 302 body fat monitor). Continuous variables were compared using the t-test or Wilcoxon U-test. Frequency distributions were compared using chi-squared tests. With respect to BMI, most of the patients (n = 1793; 53 %) were overweight or obese, 1349 (40 %) showed a normal BMI and 218 (7 %) a low BMI. The majority of cardiovascular (61 %), rheumatological (61.1 %) and metabolic (60.4 %) medication was administered to overweight and obese patients. Parallel findings could be obtained by analysing the percentage of body fat and the frequency of medication. Overall, 82.5 % of all medication was given to patients with a body fat content >20 %. Our results support the importance of weight-reduction programmes in order to prevent an overall increase in the costs of medication as a consequence of overweight and obesity.     

解偶联蛋白3基因启动子区-55(C>T)多态与中国人静息能量消耗及体脂含量与分布的关系

目的研究解偶联蛋白3基因(UCP3)启动子区-55(C>T)多态与中国人静息能量消耗、体脂参数的关系。方法在300名中国人(正常体重91人,超重/肥胖209人)中,用聚合酶链反应-限制性片段长度多态性(polymerase chain reaction-restrictionfragment length polymorphisms ,PCR-RFLP)检测UCP3基因启动子区-55(C>T)变异,并测定其静息能量消耗、体脂含量及分布。结果UCP3基因启动子区-55(C>T)多态基因型频率与肥胖及肥胖类型均无相关。正常体重组TT基因型者静息能量消耗水平显著高于CT及CC基因型者(P<0·05) ;超重/肥胖组各基因型者间比较亦有同样趋势。在超重/肥胖组,TT基因型者FM/FFM值与CT及CC基因型者差异有显著意义(P<0·01)。结论UCP3基因启动子区-55(C>T)多态与中国人静息能量消耗相关,该变异可能通过对静息能量消耗的影响调节机体的能量代谢。     

Fat mass rather than muscle strength is the major determinant of physical function and disability in postmenopausal women younger than 75 years of age

OBJECTIVE: Few studies have investigated the relationships between body composition, functional ability, and age-related disability in postmenopausal women. We investigated the relative role of fat mass, lean mass, and muscle strength in the development of disability in a group of healthy postmenopausal women younger than 75 years. DESIGN: We performed a cross-sectional study among 396 independently living women aged 56-73 years, randomly selected between 8 and 30 years after menopause. Lean mass and fat mass were assessed by dual-energy x-ray absorptiometry. Muscle strength (grip and leg extensors) was assessed using dynamometry. Functional ability was estimated by Physical Performance Score, physical activity during the preceding year, and impairment in activities of daily living. RESULTS: Of the participants, 43.7 % were overweight (25 > or = BMI < 30 kg/m2), and 17.7% were obese (BM I > or = 30 kg/m2). Higher muscle strength was observed with increasing lean body mass, and participants with higher muscle strength scored better in the physical performance score and activities of daily living. Higher fat mass was significantly associated with a lower physical performance score, lower physical activity, and a higher frequency of disability. Increasing fat mass was associated with increasing lean mass and decreasing lean/fat ratio. The increase in lean mass and muscle strength associated with higher fat mass was mainly localized in the legs. CONCLUSIONS: Our results support the role of fat mass as the primary risk marker for disability, which might later accelerate by the age-related decrease in lean mass and the development of sarcopenia after the age of 75 years.     

Structural and biochemical characteristics of various white adipose tissue depots

It is now widely accepted that white adipose tissue (WAT) is not merely a fuel storage organ, but also a key component of metabolic homoeostatic mechanisms. Apart from its major role in lipid and glucose metabolism, adipose tissue is also involved in a wide array of other biological processes. The hormones and adipokines, as well as other biologically active agents released from fat cells, affect many physiological and pathological processes. WAT is neither uniform nor inflexible because it undergoes constant remodelling, adapting the size and number of adipocytes to changes in nutrients' availability and hormonal milieu. Fat depots from different areas of the body display distinct structural and functional properties and have disparate roles in pathology. The two major types of WAT are visceral fat, localized within the abdominal cavity and mediastinum, and subcutaneous fat in the hypodermis. Visceral obesity correlates with increased risk of insulin resistance and cardiovascular diseases, while increase of subcutaneous fat is associated with favourable plasma lipid profiles. Visceral adipocytes show higher lipogenic and lipolytic activities and produce more pro-inflammatory cytokines, while subcutaneous adipocytes are the main source of leptin and adiponectin. Moreover, adipose tissue associated with skeletal muscles (intramyocellular and intermuscular fat) and with the epicardium is believed to provide fuels for skeletal and cardiac muscle contraction. However, increased mass of either epicardial or intermuscular adipose tissue correlates with cardiovascular risk, while the presence of the intramyocellular fat is a risk factor for the development of insulin resistance. This review summarizes results of mainly human studies related to the differential characteristics of various WAT depots.     

广西成人身体脂肪参数随年龄变化趋势

目的 测量广西成年人群各身体脂肪参数,探讨其脂肪含量分布随年龄及性别变化特点。方法 通过随机抽样方法选取广西籍男性居民1558例,女性居民2132例,将研究对象按10岁为1个年龄组分组,用体成分仪测量并记录各脂肪参数,采用SPSS 22.0统计学软件分析数据。结果 广西女性总脂肪量、各部位总脂肪量、各年龄组皮下及四肢脂肪含量均高于男性,男性各部位脂肪量随着年龄增加呈先上升后下降趋势,在30岁时各脂肪参数达峰值,且此年龄段的超重和肥胖发生率最高,男性在30~40岁时内脏脂肪和躯干脂肪多于女性,表现为向心性肥胖为主。女性总脂肪含量、各年龄组各部位脂肪含量在女性20~50岁时呈快速上升阶段,并在40岁达到高峰,50岁后缓慢下降并逐渐趋于平稳。青年女性主要表现为皮下及四肢脂肪增多为主,在40~50岁后主要表现为向心性肥胖,此年龄组超重和肥胖发生率最高。结论 广西男女人群身体脂肪含量随年龄增长先增加后减少,男性20~30岁和女性20~50岁是身体脂肪含量变化趋势的关键时间点。除了内脏及躯干脂肪含量外,不同年龄组及不同部位脂肪含量均为广西女性人群多于男性人群,广西青壮年男性的内脏和躯干脂肪含量高于女性。     

Obesity and regional fat distribution in Kenyan populations: Impact of ethnicity and urbanization

Background: Obesity is increasing rapidly in Africa, and may not be associated with the same changes in body composition among different ethnic groups in Africa.

Objective: To assess abdominal visceral and subcutaneous fat thickness, prevalence of obesity, and differences in body composition in rural and urban Kenya.

Subjects and methods: In a cross-sectional study carried out among Luo, Kamba and Maasai in rural and urban Kenya, abdominal visceral and subcutaneous fat thicknesses were measured by ultrasonography. Height and weight, waist, mid-upper arm circumferences, and triceps skinfold thickness were measured. Body mass index (BMI), arm fat area (AFA) and arm muscle area (AMA) were calculated.

Results: Among 1430 individuals (58.3% females) aged 17–68 years, abdominal visceral and subcutaneous fat, BMI, AFA and waist circumference (WC) increased with age, and were highest in the Maasai and in the urban population. AMA was only higher with increasing age among males. The prevalence of overweight (BMI ≥ 25) (39.8% vs. 15.8%) and obesity (BMI ≥ 30) (15.5% vs. 5.1%) was highest in the urban vs. rural population.

Conclusion: Abdominal visceral and subcutaneous fat thickness was higher with urban residency. A high prevalence of overweight and obesity was found. The Maasai had the highest overall fat accumulation.     

Body fatness in relation to physical activity and selected socioeconomic parameters of adolescents aged 15–17 years in Merida,Yucatan

Background: Increasing rates of overweight and obesity in adolescents are major concerns in many countries, including Mexico.

Objectives: To study anthropometric and body composition characteristics (BCC) and their relations with socioeconomic status (SES), biological history and physical activity (PA) of school-going adolescent boys and girls in the city of Merida, Yucatan, Mexico.

Subjects and methods: In this cross-sectional study, a sample of 321 adolescents (156 boys and 165 girls) aged 15–17 years from public and private schools in Merida, was taken from a study carried out in 2008–2009.

Results: Body mass index had significant correlations to BCC (fat mass and fat-free mass). The rate of stunting was higher in girls (18.20%) than in boys (7.69%). Stunted adolescents had higher body fat (%) than normally growing peers. High rates of overweight (boys 26.28%, girls 24.24%) and obesity (boys 10.26%, girls 6.06%) were recorded. SES (parents’ age, education and occupation; crowding index in the family; household food expenditure), participants’ biological history and PA are related with height and BCC by age and sex.

Conclusion: Adolescents with excess weight (overweight?+?obesity) reported being less physically active. SES and PA were strongly related to growth and body fatness in the studied adolescents.     

Body composition and serum levels of adiponectin, vascular endothelial growth factor, and interleukin-6 in patients with rheumatoid arthritis

Aim. To investigate differences in body composition and body mass index (BMI) in patients with rheumatoid arthritis (RA) and their correlations with serum production of adiponectin, interleukin-6 (IL-6), and vascular endothelial growth factor (VEGF). Methods. The study included 83 patients (age 53±5 years) with RA treated with methotrexate. We determined their BMI, fat mass, and fat-free mass using bioimpedance analysis, and serum concentrations of adiponectin, VEGF, and IL-6 using immunoassay analysis. Results. Normal BMI was found in 39 (47%), overweight and obesity in 26 (31%), and underweight in 18 (22%) patients. Concentration of adiponectin was lower in overweight/obese patients than in patients with normal BMI (2.1 [0.8-3.9] μg/mL vs 8.9 (7.2-11.3) μg/mL). In underweight patients, it was moderately increased (12.7 [9.3-14.8] μg/mL) and the correlation between the concentrations of adiponectin and IL-6 was positive (r=0.4; P=0.01). Concentrations of VEGF and IL-6 were increased in all groups with RA. The overweight/obese group showed a negative correlation between the concentrations of adiponectin and VEGF (r=- 0.34; P=0.04), a positive correlation between VEGF concentration and fat mass (r=0.39; P=0.02), and a negative correlation between adiponectin concentration and fat mass (r=- 0.23; P=0.02). Conclusion. Inflammatory and angiogenesis activation was found in RA patients with all types of body composition, but only in those with obesity and overweight there was a direct antagonism between adiponectin and VEGF. Further research is needed to identify possible regimens of metabolic correction in different variations of body composition.     

Behavioral and physiological indices related to BMI in a cohort of primary schoolchildren in Greece.

The purpose of this study was to investigate the differences between normal weight and overweight primary schoolchildren in terms of certain cardiovascular disease (CVD) risk factors and furthermore to identify behavioral correlates significantly affecting their body mass index (BMI). The sample consisted of 198 children with a mean age of 11.5 +/- 0.4 years (106 females and 92 males). Data was obtained on children anthropometry, plasma lipids, plasma glucose, dietary intake, cardiorespiratory fitness, and physical activity. Significant gender differences were observed for most of these parameters, with boys being more active and fit but also spending more time on sedentary activities and exhibiting higher intake of energy and fat compared to girls. Using the International Obesity Task Force's (IOTF) BMI cut-off points, the prevalence of overweight and obesity was estimated to be 35.6% and 6.7% among boys and 25.7% and 6.7% among girls, respectively. Overweight and obese children had higher levels of plasma triglycerides (TG) and total cholesterol to HDL-cholesterol (TC/HDL-C) ratio and lower levels of HDL-C and physical fitness compared to their normal-weight peers. Among the behavioral variables tested, only participation in organized sports, cardiorespiratory fitness, and TV watching were significantly correlated with BMI, while energy and fat intake were found to have no significant effect. The current study suggests that even in childhood, overweight and obesity are indicative of an unfavorable lipidemic profile. Among the behavioral parameters known to affect BMI, those found to exert a significant effect were organized physical activities, cardiorespiratory fitness, and TV watching, but not energy or fat intake.     

“Is obesity linked to aging?”: Adipose tissue and the role of telomeres

Obesity is a condition in which excess or abnormal fat accumulation may present with adverse effects on health and decreased life expectancy. Increased body weight and adipose tissue accumulation amplifies the risk of developing various age-related diseases, such as cardiovascular disease, type 2 diabetes mellitus, musculoskeletal disorders, respiratory diseases and certain types of cancer. This imbalance in body composition and body weight is now recognized as a state of increased oxidative stress and inflammation for the organism. Increasing oxidative stress and inflammation affect telomeres. Telomeres are specialized DNA-protein structures found at the ends of eukaryotic chromosomes and serve as markers of biological aging rate. They also play a critical role in maintaining genomic integrity and are involved in age-related metabolic dysfunction. Erosion of telomeres is hazardous to healthy cells, as it is a known mechanism of premature cellular senescence and loss of longevity. The association of telomeres and oxidative stress is evident in cultured somatic cells in vitro, where oxidative stress enhances the process of erosion with each cycle of replication. Shorter telomeres have been associated with increasing body mass index, increased adiposity, and more recently with increasing waist to hip ratio and visceral excess fat accumulation. Furthermore, many of the metabolic imbalances of obesity (e.g. glycemic, lipidemic, etc.) give rise to organ dysfunction in a way that resembles the accelerated aging process. This article is a non-systematic review of the evidence linking obesity and accelerated aging processes as they are regulated by telomeres.     

Childhood obesity in Canada: a review of prevalence estimates and risk factors for cardiovascular diseases and type 2 diabetes.

Childhood obesity in Canada has become increasingly prevalent over the past 2 decades. Despite inconsistencies regarding different anthropometric indicators, cut-offs, and reference populations, both regional and national investigations have revealed high numbers of overweight and obese children and adolescents. A number of risk factors and health consequences have been associated with increased levels of body fatness in youth. Specifically, risk factors for cardiovascular diseases (CVD) and type 2 diabetes are known to develop early in life and tend to emerge in clusters among overweight youngsters. Unhealthy lifestyle behaviours (i.e., physical inactivity), a genetic disposition, and a centralized body fat distribution, all contribute to increased risk. In order to prevent future generations of children from experiencing increased morbidity and mortality as overweight and obese adults, coordinated efforts at all levels (family, school, community, and government) must be established with a long-term commitment to promote healthy nutrition and physical activity behaviours in our youth.     

Evidence for the intra-uterine programming of adiposity in later life

Aim: Research in animals has shown that altering foetal nutrition by under-nourishing or over-nourishing the mother or rendering her diabetic or foetal exposure to glucocorticoids and toxins can programme obesity in later life. The increased adiposity is mediated by permanent changes in appetite, food choices, physical activity and energy metabolism. In humans, increased adiposity has been shown in people who experienced foetal under-nutrition due to maternal famine or over-nutrition due to maternal diabetes. Lower birth weight (a proxy for foetal under-nutrition) is associated with a reduced adult lean mass and increased intra-abdominal fat. Higher birth-weight caused by maternal diabetes is associated with increased total fat mass and obesity in later life. There is growing evidence that maternal obesity, without diabetes, is also a risk factor for obesity in the child, due to foetal over-nutrition effects. Maternal smoking is associated with an increased risk of obesity in the children, although a causal link has not been proven. Other foetal exposures associated with increased adiposity in animals include glucocorticoids and endocrine disruptors.

Conclusions: Reversing the current obesity epidemic will require greater attention to, and better understanding of, these inter-generational (mother-offspring) factors that programme body composition during early development.     

Metabolic and cardiovascular risk factors in Klinefelter syndrome

Klinefelter syndrome (KS), which normally presents with a 47,XXY karyotype, is the most common sex chromosome disorder in males. It is also the most common genetic cause of male infertility. KS subjects are typically tall, with small and firm testes, gynecomastia, broad hips, and sparse body hair, although a less evident presentation is also possible. KS is also characterized by a high prevalence of hypogonadism, metabolic syndrome (MetS) and cardiovascular disease. The aim of this article is to systematically review metabolic and the cardiovascular risk factors in KS patients. Hypogonadism has an important role in the pathogenesis of the changes in body composition (particularly visceral obesity) and hence of insulin resistance and MetS, but the association between KS and MetS may go beyond hypogonadism alone. From childhood, KS patients may show an increase in visceral fat with a reduction in lean body mass and an increase in glucose and impaired fat metabolism. Their increased incidence of congenital anomalies, epicardial adipose tissue, and thromboembolic disease suggests they have a higher risk of cardiovascular disease. There is conflicting evidence on the effects of testosterone therapy on body composition and metabolism.     

High school students'' attitudes and knowledge of food consumption and body image: implications for school based education

One-hundred-and-forty-one high school students from Holon between the ages of 14 and 18 years participated in the study. The aims of the study were to investigate their nutritional habits, ascertain their body image, measure their knowledge concerning nutrition and finally to determine their attitudes regarding overweight, obese people and dieting. The study is a cross-sectional survey and the students involved completed a self administered questionnaire anonymously at school. The response rate was 97%. Forty-four percent of the total study population expressed a subjective feeling of being obese while, in truth, only 10% of them were actually overweight, and 48% among all participants practised weight reduction diets (girls three times more than boys). In addition to that another 53% of the pupils expressed the desire to be thinner than they were (girls four times more than boys). Nine percent of the study group experienced self-induced anorectic episodes at sometime during the past few years. It was observed that the study group's knowledge concerning food composition and nutrition remains insufficient. As far as their attitude concerning obesity, it was observed that 31% of the students regarded obesity as a handicap. Students who were athletics demonstrated more severe and stricter attitudes towards nutrition and obesity. Most of the information concerning nutrition was obtained through the media. School education about food and nutrition only amounted to 28.3% of the total. Seventy-nine percent of the students believe that nutrition should be integrated into their curriculum. Forty-four percent of the students feel themselves to be overweight, and 53.4% want to be thinner. Half of the students were on various diets. The students' knowledge of food and nutrition, the risk of obesity and the danger of excessive diets was insufficient. Most students presented negative attitudes towards obesity and overweight people. The media was the principal source of information on all these areas. Our main conclusion is that an educational nutrition program should be given to pupils in school by physicians and dietitians during all the years of public school attendance. The instructions of these programs should emphasize the importance of balanced nutritional regimes, as well as the risk and consequences of extreme dieting.