Assessing weight perception accuracy to promote weight loss among U.S. female adolescents: A secondary analysis

<p>Abstract</p> <p>Background</p> <p>Overweight and obesity have become a global epidemic. The prevalence of overweight and obesity among U.S. adolescents has almost tripled in the last 30 years. Results from recent systematic reviews demonstrate that no single, particular intervention or strategy successfully assists overweight or obese adolescents in losing weight. An understanding of factors that influence healthy weight-loss behaviors among overweight and obese female adolescents promotes effective, multi-component weight-loss interventions. There is limited evidence demonstrating associations between demographic variables, body-mass index, and weight perception among female adolescents trying to lose weight. There is also a lack of previous studies examining the association of the accuracy of female adolescents' weight perception with their efforts to lose weight. This study, therefore, examined the associations of body-mass index, weight perception, and weight-perception accuracy with trying to lose weight and engaging in exercise as a weight-loss method among a representative sample of U.S. female adolescents.</p> <p>Methods</p> <p>A nonexperimental, descriptive, comparative secondary analysis design was conducted using data from Wave II (1996) of the National Longitudinal Study of Adolescent Health (Add Health). Data representative of U.S. female adolescents (N = 2216) were analyzed using STATA statistical software. Descriptive statistics and survey weight logistic regression were performed to determine if demographic and independent (body-mass index, weight perception, and weight perception accuracy) variables were associated with trying to lose weight and engaging in exercise as a weight-loss method.</p> <p>Results</p> <p>Age, Black or African American race, body-mass index, weight perception, and weight perceptions accuracy were consistently associated with the likeliness of trying to lose weight among U.S. female adolescents. Age, body-mass index, weight perception, and weight-perception accuracy were positively associated (<it>p </it>< 0.05) with trying to lose weight. Black/African American subjects were significantly less likely than their White counterparts to be trying to lose weight. There was no association between demographic or independent variables and engaging in exercise as a weight-loss method.</p> <p>Conclusions</p> <p>Findings suggest that factors influencing weight-loss efforts, including age, race, body-mass index, weight perception, and weight-perception accuracy, should be incorporated into existing or new multi-component weight-loss interventions for U.S. adolescent females in order to help reduce the national epidemic of overweight and obesity among U.S. female adolescents.</p

Nutritional knowledge, food habits and health attitude of Chinese university students –a cross sectional study–

BACKGROUND: We have previously shown that irregular lifestyle of young Japanese female students are significantly related to their desire to be thinner. In the present study, we examined the nutritional knowledge and food habits of Chinese university students and compared them with those of other Asian populations. METHODS: A self-reported questionnaire was administered to 540 students, ranging in age from 19-24 years. Medical students from Beijing University (135 men and 150 women) in Northern China and Kunming Medical College in southern China (95 men and 160 women) participated in this study. The parametric variables were analyzed using the Student's t-test. Chi-square analyses were conducted for non-parametric variables RESULTS: Our results showed that 80.5% of students had a normal BMI and 16.6 % of students were underweight with the prevalence of BMI>30 obesity being very low in this study sample. Young Chinese female students had a greater desire to be thinner (62.0%) than males (47.4%). Habits involving regular eating patterns and vegetable intake were reported and represent practices that ought to be encouraged. CONCLUSIONS: The university and college arenas represent the final opportunity for the health and nutritional education of a large number of students from the educator's perspective. Our findings suggest the need for strategies designed to improve competence in the area of nutrition

Chronic Exposure of Corals to Fine Sediments: Lethal and Sub-Lethal Impacts

Understanding the sedimentation and turbidity thresholds for corals is critical in assessing the potential impacts of dredging projects in tropical marine systems. In this study, we exposed two species of coral sampled from offshore locations to six levels of total suspended solids (TSS) for 16 weeks in the laboratory, including a 4 week recovery period. Dose-response relationships were developed to quantify the lethal and sub-lethal thresholds of sedimentation and turbidity for the corals. The sediment treatments affected the horizontal foliaceous species (Montipora aequituberculata) more than the upright branching species (Acropora millepora). The lowest sediment treatments that caused full colony mortality were 30 mg l−1 TSS (25 mg cm−2 day−1) for M. aequituberculata and 100 mg l−1 TSS (83 mg cm−2 day−1) for A. millepora after 12 weeks. Coral mortality generally took longer than 4 weeks and was closely related to sediment accumulation on the surface of the corals. While measurements of damage to photosystem II in the symbionts and reductions in lipid content and growth indicated sub-lethal responses in surviving corals, the most reliable predictor of coral mortality in this experiment was long-term sediment accumulation on coral tissue

Evidence and rationale for the World Health Organization recommended standards for Japanese encephalitis surveillance

<p>Abstract</p> <p>Background</p> <p>Japanese encephalitis (JE) is the most important form of viral encephalitis in Asia. Surveillance for the disease in many countries has been limited. To improve collection of accurate surveillance data in order to increase understanding of the full impact of JE and monitor control programs, World Health Organization (WHO) Recommended Standards for JE Surveillance have been developed. To aid acceptance of the Standards, we describe the process of development, provide the supporting evidence, and explain the rationale for the recommendations made in the document.</p> <p>Methods</p> <p>A JE Core Working Group was formed in 2002 and worked on development of JE surveillance standards. A series of questions on specific topics was initially developed. A literature review was undertaken and the findings were discussed and documented. The group then prepared a draft document, with emphasis placed on the feasibility of implementation in Asian countries. A field test version of the Standards was published by WHO in January 2006. Feedback was then sought from countries that piloted the Standards and from public health professionals in forums and individual meetings to modify the Standards accordingly.</p> <p>Results</p> <p>After revisions, a final version of the JE surveillance standards was published in August 2008. The supporting information is presented here together with explanations of the rationale and levels of evidence for specific recommendations.</p> <p>Conclusion</p> <p>Provision of the supporting evidence and rationale should help to facilitate successful implementation of the JE surveillance standards in JE-endemic countries which will in turn enable better understanding of disease burden and the impact of control programs.</p

Measured body mass index, body weight perception, dissatisfaction and control practices in urban, low-income African American adolescents

<p>Abstract</p> <p>Background</p> <p>Current understanding of the associations between actual body weight status, weight perception, body dissatisfaction, and weight control practices among low-income urban African American adolescents is limited. The knowledge can help direct future intervention efforts.</p> <p>Methods</p> <p>Cross-sectional data including measured weight and height and self-reported weight status collected from 448 adolescents in four Chicago Public Schools were used.</p> <p>Results</p> <p>The prevalence of overweight and obesity (BMI ≥ 85^thpercentile) was 39.8%, but only 27.2% considered themselves as obese, although 43.4% reported trying to lose weight. Girls were more likely to express weight dissatisfaction than boys, especially those with BMI ≥ 95^thpercentile (62.9% vs. 25.9%). BMI ≥ 85^thpercentile girls were more likely to try to lose weight than boys (84.6% vs. 66.7%). Among all adolescents, 27.2% underestimated and 67.2% correctly judged their own weight status. Multinomial logistic models show that those with BMI ≥ 85^thpercentile, self-perceived as obese, or expressed body dissatisfaction were more likely to try to lose weight; adjusted odds ratios and 95% confidence intervals were 4.52 (2.53–8.08), 18.04 (7.19–45.30), 4.12 (1.64–10.37), respectively. No significant differences were found in diet and physical activity between those trying to lose weight and those not trying, but boys who reported trying to lose weight still spent more television time (P < 0.05).</p> <p>Conclusion</p> <p>Gender differences in weight perception, body dissatisfaction, and weight control practices exist among African American adolescents. One-third did not appropriately classify their weight status. Weight perception and body dissatisfaction are correlates of weight control practices. Adolescents attempting to lose weight need be empowered to make adequate desirable behavioral changes.</p

Interaction Between Marginal Zinc and High Fat Supply on Lipid Metabolism and Growth of Weanling Rats

The impact of a moderate Zn deficiency on growth and plasma and liver lipids was investigated in two 4-week experiments with male weanling rats fed fat-enriched diets. Semisynthetic, approximately isocaloric diets containing 3% soybean oil were supplemented with either 7 or 100 mg Zn/kg diet and with 22% beef tallow (BT) or sunflower oil (SF). In Experiment 1, which compared the dietary fat level and the fat source in a factorial design of treatments, all diets were fed ad libitum to 6 × 8 animals, whereas intake of the high-Zn BT and SF diets was restricted in Experiment 2 (5 × 6 rats) to the level of intake of the respective low-Zn diets. The low-Zn SF diet consistently depressed food intake and final live weights of the animals to a greater extent than the other low-Zn diets, while intake and growth were comparable among the animals fed the high-Zn diets. The marginal Zn deficit per se did not alter plasma triglyceride and cholesterol concentrations nor hepatic concentrations of triglyceride, cholesterol and phospholipids. The fatty acid pattern of liver phospholipids did not indicate that chain elongation and desaturation of fatty acids was impaired by a lack of zinc. It was concluded that dietary energy and fat intake, and fat source have a greater effect on plasma and liver lipids than a moderate Zn deficiency. Marginally Zn-deficient diets enriched with sunflower oil as a major energy source cause a greater growth retardation than diets rich in carbohydrates or beef tallow

Germ band retraction as a landmark in glucose metabolism during Aedes aegypti embryogenesis

<p>Abstract</p> <p>Background</p> <p>The mosquito <it>A. aegypti </it>is vector of dengue and other viruses. New methods of vector control are needed and can be achieved by a better understanding of the life cycle of this insect. Embryogenesis is a part of <it>A. aegypty </it>life cycle that is poorly understood. In insects in general and in mosquitoes in particular energetic metabolism is well studied during oogenesis, when the oocyte exhibits fast growth, accumulating carbohydrates, lipids and proteins that will meet the regulatory and metabolic needs of the developing embryo. On the other hand, events related with energetic metabolism during <it>A. aegypti </it>embryogenesis are unknown.</p> <p>Results</p> <p>Glucose metabolism was investigated throughout <it>Aedes aegypti </it>(Diptera) embryonic development. Both cellular blastoderm formation (CBf, 5 h after egg laying - HAE) and germ band retraction (GBr, 24 HAE) may be considered landmarks regarding glucose 6-phosphate (G6P) destination. We observed high levels of glucose 6-phosphate dehydrogenase (G6PDH) activity at the very beginning of embryogenesis, which nevertheless decreased up to 5 HAE. This activity is correlated with the need for nucleotide precursors generated by the pentose phosphate pathway (PPP), of which G6PDH is the key enzyme. We suggest the synchronism of egg metabolism with carbohydrate distribution based on the decreasing levels of phosphoenolpyruvate carboxykinase (PEPCK) activity and on the elevation observed in protein content up to 24 HAE. Concomitantly, increasing levels of hexokinase (HK) and pyruvate kinase (PK) activity were observed, and PEPCK reached a peak around 48 HAE. Glycogen synthase kinase (GSK3) activity was also monitored and shown to be inversely correlated with glycogen distribution during embryogenesis.</p> <p>Conclusions</p> <p>The results herein support the hypothesis that glucose metabolic fate changes according to developmental embryonic stages. Germ band retraction is a moment that was characterized as a landmark in glucose metabolism during <it>Aedes aegypti </it>embryogenesis. Furthermore, the results also suggest a role for GSK3 in glycogen balance/distribution during morphological modifications.</p

Biomarkers in Natural Fish Populations Indicate Adverse Biological Effects of Offshore Oil Production

Despite the growing awareness of the necessity of a sustainable development, the global economy continues to depend largely on the consumption of non-renewable energy resources. One such energy resource is fossil oil extracted from the seabed at offshore oil platforms. This type of oil production causes continuous environmental pollution from drilling waste, discharge of large amounts of produced water, and accidental spills.Samples from natural populations of haddock (Melanogrammus aeglefinus) and Atlantic cod (Gadus morhua) in two North Sea areas with extensive oil production were investigated. Exposure to and uptake of polycyclic aromatic hydrocarbons (PAHs) were demonstrated, and biomarker analyses revealed adverse biological effects, including induction of biotransformation enzymes, oxidative stress, altered fatty acid composition, and genotoxicity. Genotoxicity was reflected by a hepatic DNA adduct pattern typical for exposure to a mixture of PAHs. Control material was collected from a North Sea area without oil production and from remote Icelandic waters. The difference between the two control areas indicates significant background pollution in the North Sea.It is most remarkable to obtain biomarker responses in natural fish populations in the open sea that are similar to the biomarker responses in fish from highly polluted areas close to a point source. Risk assessment of various threats to the marine fish populations in the North Sea, such as overfishing, global warming, and eutrophication, should also take into account the ecologically relevant impact of offshore oil production