Exercise alone is an effective strategy for reducing obesity and related comorbidities

The commonly held view that exercise alone is not a useful strategy for obesity reduction is drawn from studies with limitations that confound interpretation. Recent evidence counters the dogma that daily exercise produces only modest weight loss and suggests that exercise without diet restriction is an effective strategy for reducing obesity and related co-morbidities.     

Physical activity and obesity in children

Globally, obesity is affecting an increasing proportion of children. Physical activity plays an important role in the prevention of becoming overweight and obese in childhood and adolescence, and reducing the risk of obesity in adulthood. Puberty and the following adolescent period are acknowledged as particularly vulnerable times for the development of obesity due to sexual maturation and, in many individuals, a concomitant reduction in physical activity. In many Western settings, a large proportion of children and adolescents do not meet recommended physical activity guidelines and, typically, those who are more physically active have lower levels of body fat than those who are less active. Active behaviours have been displaced by more sedentary pursuits which have contributed to reductions in physical activity energy expenditure. Without appropriate activity engagement there is an increased likelihood that children will live less healthy lives than their parents. Owing to the high risk of overweight adolescents becoming obese adults, the engagement of children and adolescents in physical activity and sport is a fundamental goal of obesity prevention.     

Physical activity patterns and obesity in Hispanic and non-Hispanic white women

PURPOSE: Cultural differences in diet and lifestyle patterns probably contribute to cancer rates among ethnic groups in the United States. In this paper, we describe physical activity patterns of Hispanic and non-Hispanic white women living in the southwestern United States and the effects of these patterns on obesity. METHODS: We use data from population-based controls (N = 2039) participating in the 4-Corner's Breast Cancer Study to evaluate associations between physical activity and language acculturation and the associated effects on obesity. RESULTS: The majority of both Hispanic and non-Hispanic white women did not perform 30 min of activity > or = 5 d x wk(-1), although a greater percentage of Hispanic women meet the goal if they reported higher levels of language acculturation. However, the type and intensity of activities performed by Hispanic and non-Hispanic women differed; Hispanic women reported more housework, dependent care giving, dancing, and work activity. Differences in activity patterns existed by level of language acculturation among Hispanic women. Hispanic women who had higher levels of language acculturation reported continued activity throughout their lives. Prevalence of obesity was greater among Hispanic than non-Hispanic white women for all levels of language acculturation. Women with intermediate levels of language acculturation had the greatest relative risk of obesity compared with non-Hispanic white women (odds ratio (OR) = 2.79, 95% confidence interval (CI) = 1.85-4.02); Hispanic women with higher levels of language acculturation also were at increased relative risk of obesity (OR = 1.78, 95% CI = 1.28-2.47). CONCLUSIONS: Interventions to increase physical activity among Hispanic women are needed to address the problems of physical inactivity and obesity in that population. Facilitating culturally relevant activities might be reasonable approaches to increasing physical activity.     

A longitudinal study of fitness and activity in girls predisposed to obesity

PURPOSE: To determine whether physical activity and fitness change in girls with and without a predisposition to obesity from 8 to 10 yr of age. METHODS: Normal-weight girls (N = 91) were recruited at 8 yr of age according to parental body mass index (BMI): LN = girls with two lean (BMI < 25 kg.m-2) parents, LNOB = girls with one obese and one lean parent, and OB = girls with two obese (BMI > 28 kg.m-2) parents. A longitudinal study was undertaken with annual assessments at 8, 9, and 10 yr of age. The primary outcomes were fitness ([OV0312]O2peak) measured by treadmill testing, and physical activity measured by heart rate monitoring and by questionnaire. Sedentary behavior was assessed by questionnaire. RESULTS: [OV0312]O2peak (mL.kg-1.min-1) did not change over time; however, [OV0312]O2peak (L.min-1 and mL.kg-1.min-1), time on the treadmill, and treadmill stage were different across groups (P < 0.02). Girls with LNOB parents had a lower absolute [OV0312]O2 than the LN girls by 2.5 mL.kg-1.min-1 (P < 0.05). The OB group had a 3.9 mL.kg-1.min-1 lower [OV0312]O2 than the LN group (P < 0.001). The girls of LN parents also exercised longer on the treadmill (P < 0.05) than girls with OB parents. The percent of the day spent active on the weekday and weekend did not change over time or between groups. Time spent watching TV during the school year and summer was similar over the study period and between groups. CONCLUSION: Our data suggest that fitness and physical activity remain fairly constant in girls from 8 to 10 yr of age, but girls of obese parents tend to be less fit.     

胃左动脉栓塞减肥

【摘要】 肥胖是一个重要的公共健康问题,与26种疾病具有因果关系。胃左动脉栓塞减肥,作为一种新兴的介入微创减肥方式,能够减少胃底部ghrelin激素的分泌,在动物模型中验证了其有效性和安全性,并在短期随访的临床研究中也取得了良好的减轻体重的效果,且并发症轻微。本文对胃左动脉栓塞减肥的最新研究进展进行了归纳分析。     

Fitness,physical activity,working memory,and neuroelectric activity in children with overweight/obesity

The aim of the present study was to examine the associations of physical fitness, sedentary time, and physical activity (PA) with working memory and neuroelectric activity in children with overweight/obesity. Seventy‐nine children with overweight/obesity (10.2 ± 1.1 years old) participated in this cross‐sectional study. We assessed physical fitness components (ie, muscular strength, speed agility, and cardiorespiratory fitness) using the ALPHA battery. Sedentary time and PA were assessed by GT3X+accelerometers (ActiGraph). Working memory was assessed using the delayed non‐matched‐to‐sample task; mean reaction time (RT) and response accuracy were registered. Neuroelectric activity (ie, P3 amplitude and latency) was registered using the ActiveTwo System of BioSemi electroencephalogram. Higher upper‐limb absolute strength was associated with lower response accuracy (P = 0.023), while higher lower‐limb relative‐to‐weight strength was associated with larger P3 amplitude (P < 0.05). Higher speed agility and cardiorespiratory fitness levels were associated with shorter mean RT and larger P3 amplitude, and speed agility was also associated with shorter P3 latency (all P < 0.05). Vigorous PA was associated with larger P3 amplitude (P < 0.05). No associations were found for sedentary time or the rest of PA intensities (P ≥ 0.05). In addition to cardiorespiratory fitness, muscular strength and speed agility are also associated with working memory and neuroelectric activity in children with overweight/obesity. The association between PA and working memory is intensity‐dependent, as significant findings were only observed for vigorous PA. Randomized controlled trials in this population would help to better understand whether improvements in different components of fitness and PA lead to better working memory and underlying brain function.     

纤溶酶原激活剂及其活性测定

纤溶酶原激活剂 (plasminogen activator,PA)是一种特异性的蛋白水解酶 ,它能将无活性的酶前体转变为纤溶酶 (plasmin)。纤溶酶是一种有效的非特异性的蛋白水解酶 ,能够裂解血液内的纤维蛋白凝块使其成为可溶性的多肽。本文描述了纤港酶原激活系统的一些生化特征 ,及对纤溶酶原激活剂活性的测定方法。纤溶酶原激活剂在血栓性疾病和出血性疾病的诊断具有潜在应用价值。     

Exercise and diet in obesity treatment: an integrative system dynamics perspective

PURPOSE: Demonstrate the utility of System Dynamics computer modeling to study and gain insight into the impacts of physical activity and diet on weight gain and loss. METHODS: A holistic System Dynamics computer model is presented that integrates the processes of human metabolism, hormonal regulation, body composition, nutrition, and physical activity. These processes are not independent of one another, and the model captures the complex interdependencies between them in the regulation of body weight and energy metabolism. The article demonstrates how such an integrative simulation model can serve as a viable laboratory tool for controlled experimentation to investigate the impacts of physical activity and diet on body weight and composition. RESULTS: In one experiment, weight loss from a moderate level of daily exercise was slightly less than the loss from dieting. Although exercise did have a favorable impact on body composition by protecting against the loss in fat-free mass (FFM), it, however, failed to blunt the drop in resting energy expenditure (REE) that accompanies diet-based weight loss. The smaller loss in FFM did indeed induce a smaller drop in REE, however, the preservation of FFM also affected a relatively larger loss in FM, which, in turn, induced a larger adaptive reduction in the metabolic rate. The two adaptations almost totally offset one another, causing minimal differences in REE. In a second experiment, exercise regimens of moderate- to high-level intensity proved counterproductive as weight-reducing strategies. However, when the diet was changed from a balanced composition to one that was highly loaded with carbohydrates, it became possible to sustain the intense exercise regimen over the experimental period and achieve a significant drop in body weight. CONCLUSION: The results underscore the significant interaction effects between physical activity, diet, and body composition and demonstrate the utility of computer-based experimentation to study, gain insight into, and make predictions about their dynamics.     

Physical activity in the management of obesity in adults: A position statement from Exercise and Sport Science Australia

This Position Statement examines the evidence for physical activity in weight and adiposity loss, prevention of weight and adiposity gain, and in weight regain in adults, and provides guidance on implications for exercise practitioners. Research evidence indicates that >150 min but preferably 300 min per week of aerobic activity of at least moderate intensity is required to prevent weight and adiposity gain, and at least the upper end of this range of activity to prevent weight regain after weight loss. For meaningful weight and total adiposity loss, a minimum of 300–420 min per week of aerobic activity of at least moderate intensity is required. The evidence around the volume of aerobic physical activity required to reduce central adiposity is emerging, and research suggests that it may be substantially less than that required for weight loss. The impact of high-intensity physical activity and resistance exercise for weight management is uncertain. During consultations for weight management, exercise practitioners should advise that metabolic and cardiovascular health benefits can be achieved with physical activity at any weight, and irrespective of weight change.     

Relationship of obesity with physical activity, aerobic fitness and muscle strength in Flemish adults

AIM: The aim of this study was to analyse differences in physical activity, cardiorespiratory fitness (CRF) and muscle strength between normal weight, overweight and obese adults and to investigate the role of physical activity variables in the analyses of differences in CRF and muscle strength between these groups. METHODS: A total of 807 men and 633 women (age: 18-75 years) were included in this cross-sectional study. Weight, height, waist circumference (WC) and bioelectrical impedance were measured. Different dimensions of physical activity were assessed using a validated questionnaire. CRF (VO(2peak)) was evaluated by a maximal test on a cycle ergometer. Knee strength was measured with a calibrated Biodex System Pro 3 dynamometer. Three methods were used for classification in obesity groups: body mass index (BMI), WC and combined BMI-WC classification. RESULTS: Health-related sports and physical activity level are negatively associated with obesity in men, but not in women. Television viewing is positively associated with obesity, while VO(2peak)/fat free mass (FFM) and knee strength/FFM show a negative association with obesity in both genders. Overall, subjects with normal WC seem to be more physically active and to have somewhat better values for CRF compared to those with high WC within the same BMI category. Lower values for relative CRF and knee strength in obese subjects compared to their lean counterparts remain after adjustment for physical activity. CONCLUSION: This study confirms the lower level of physical activity and the impaired CRF and knee strength in obese adults compared to their lean counterparts. This study also sustains the importance of measuring WC and CRF during clinical examinations.     

Risk of obesity in relation to physical activity tracking from youth to adulthood

PURPOSE: Maintaining a high level of physical activity throughout one's lifetime may decrease the risk of obesity. We evaluated how physical activity patterns from youths (9-18 yr) to adulthood are associated with body mass index (BMI) and waist circumference (WC) in a population of young adults. METHODS: As part of the longitudinal Cardiovascular Risk in Young Finns Study, we assessed physical activity over a 21-yr follow-up in a cohort of 1319 subjects. Physical activity was measured using a questionnaire completed in conjunction with a medical examination. RESULTS: During the follow-up, 33.1% of men and 32.0% of women were classified as persistently active, and 11.5% of men and 7.4% of women as persistently inactive. Both decreasingly active and persistently inactive subjects were more likely to be obese as adults compared with persistently active subjects. In women, being decreasingly active from youth to adulthood compared with being persistently active was independently associated with the risk of being overweight (BMI = 25.0-29.9 kg.m(-2), odds ratio (OR) = 2.35, confidence interval (CI) = 1.16-4.78), obese (BMI > or = 30.0 kg.m(-2), OR = 2.72, CI = 1.04-7.09), mildly abdominally obese (WC = 800-879 mm, OR = 2.21, CI = 1.01-4.84), and severely abdominally obese (WC > or = 880 mm, OR = 2.19, CI = 1.03-4.67), after adjustment for several variables including childhood fatness. In men, decreasing physical activity during their lifetime was associated with mild (WC = 940-1019 mm, odds ratio (OR) = 1.78, CI = 1.00-3.19) and severe (WC > or = 1020 mm, OR = 2.47, CI = 1.27-4.78) abdominal obesity in unadjusted analyses, but these two associations disappeared after adjustment for confounding variables (OR = 1.51, CI = 0.72-3.17 and OR = 1.62, CI 0.66-4.02, respectively). In men, changes in physical activity were not associated with obesity or overweight as defined by cut-points of BMI. CONCLUSIONS: Maintaining a high level of physical activity from youth to adulthood is independently associated with lower risk of abdominal obesity in among women, but not men. These findings suggest that changes in physical activity patterns during the lifetime may contribute to the development of abdominal obesity in women.