Investigating mechanisms underpinning the detrimental impact of a high-fat diet in the developing and adult hypermuscular myostatin null mouse

Background: Obese adults are prone to develop metabolic and cardiovascular diseases. Furthermore, over-weight expectant mothers give birth to large babies who also have increased likelihood of developing metabolic and cardiovascular diseases. Fundamental advancements to better understand the pathophysiology of obesity are critical in the development of anti-obesity therapies not only for this but also future generations. Skeletal muscle plays a major role in fat metabolism and much work has focused in promoting this activity in order to control the development of obesity. Research has evaluated myostatin inhibition as a strategy to prevent the development of obesity and concluded in some cases that it offers a protective mechanism against a high-fat diet. Results: We hypothesised that myostatin inhibition should protect not only the mother but also its developing foetus from the detrimental effects of a high-fat diet. Unexpectedly, we found muscle development was attenuated in the foetus of myostatin null mice raised on a high-fat diet. We therefore re-examined the effect of the high-fat diet on adults and found myostatin null mice were more susceptible to diet-induced obesity through a mechanism involving impairment of inter-organ fat utilization. Conclusions: Loss of myostatin alters fatty acid uptake and oxidation in skeletal muscle and liver. We show that abnormally high metabolic activity of fat in myostatin null mice is decreased by a high-fat diet resulting in excessive adipose deposition and lipotoxicity. Collectively, our genetic loss-of-function studies offer an explanation of the lean phenotype displayed by a host of animals lacking myostatin signalling. Keywords: Muscle, Obesity, High-fat diet, Metabolism, Myostatin

Underreporting of Energy Intake in Brazilian Women Varies According to Dietary Assessment: A Cross-Sectional Study Using Doubly Labeled Water

Objective Underreporting of energy intake is prevalent in food surveys, but there is controversy about which dietary assessment method provides greater underreporting rates. Our objective is to compare validity of self-reported energy intake obtained by three dietary assessment methods with total energy expenditure (TEE) obtained by doubly labeled water (DLW) among Brazilian women. Design We used a cross-sectional study. Subjects/setting Sixty-five females aged 18 to 57 years (28 normal-weight, 10 over-weight, and 27 obese) were recruited from two universities to participate. Main outcome measures TEE determined by DLW, energy intake estimated by three 24-hour recalls, 3-day food record, and a food frequency questionnaire (FFQ). Statistical analyses performed Regression and analysis of variance with repeated measures compared TEE and energy intake values, and energy intake-to-TEE ratios and energy intake-TEE values between dietary assessment methods. Bland and Altman plots were provided for each method. chi(2) test compared proportion of underreporters between the methods. Results Mean TEE was 2,622 kcal (standard deviation [SD] =490 kcal), while mean energy intake was 2,078 kcal (SD=430 kcal) for the diet recalls; 2,044 kcal (SD=479 kcal) for the food record and 1,984 kcal (SD=832 kcal) for the FFQ (all energy intake values significantly differed from TEE; P<0.0001). Bland and Altman plots indicated great dispersion, negative mean differences between measurements, and wide limits of agreement. Obese subjects underreported more than normal-weight subjects in the diet recalls and in the food records, but not in the FFQ. Years of education, income and ethnicity were associated with reporting accuracy. Conclusions The FFQ produced greater under- and overestimation of energy intake. Underreporting of energy intake is a serious and prevalent error in dietary self-reports provided by Brazilian women, as has been described in studies conducted in developed countries.

Sexagem histológica e desempenho de Oreochromis niloticus testando diâmetros de ração de acordo com o aparato bucal

Estudou-se o tamanho da boca de larvas de tilápia-do-nilo e testou-se o efeito de diferentes granulometrias da ração sobre o ganho de peso, comprimento e sobrevivência das larvas aos 30 e 60 dias de arraçoamento. Avaliou-se também o método de sexagem por meio de microscopia de luz aos 35 dias de idade. A medida da boca das larvas apresentou valores médios de 918,2±152,9μm aos cinco dias de idade. de acordo com esse dado, testaram-se três granulometrias: 0,25, 0,35 e 0,50mm. Aos 30 e aos 60 dias de arraçoamento, 10% das larvas foram medidas, pesadas e contadas para cálculo da taxa de sobrevivência. O tamanho dos grânulos testados não afetou o desempenho das larvas de tilápia nilótica com alimentação iniciada aos cinco dias pós-eclosão. Quanto à sexagem histológica aos 35 dias de idade, as gônadas apresentaram-se, em sua maioria, indiferenciadas. Recomenda-se que essa análise deva ser realizada de acordo com o tamanho dos animais e não com a idade.

Correspondência entre obesidade e hiperlipidemia em cães

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estado nutricional de indivíduos alcoolistas crônicos na internação e na alta médica, em um hospital psiquiátrico, Araçatuba/SP

Pós-graduação em Alimentos e Nutrição - FCFAR

Televisão e saúde: a obesidade em discussão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da qualidade de vida na indústria do vestuário: o caso de costureiras portadoras de lombalgias

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Characterization of circulating steroids and endocannabinoids levels in obese subjects by liquid chromatography tandem mass spectrometry

Nowadays obesity can be defined as a global epidemic. The precise identification of circulating biomarkers involved in this pathology could be essential to early diagnose potential co-morbidities and to better address the development of future therapeutic strategies. Published evidences show that circulating steroid hormones and endocannabinoids might have a role in the physiopathology of obesity; however, a precise and reliable quantification of these molecules is still lacking. In the first part of the present thesis, we developed a sensitive, specific and accurate quantification method for nine steroid hormones using a liquid chromatography tandem mass spectrometry (LC-MS/MS) system. This method has been used first for a comparative study with immunoassays, currently used in the clinical practice to quantify these molecules and then to redefine circulating reference intervals in healthy subjects. Furthermore, we measured circulating steroid hormones in three groups of subjects: normo-weight, over-weight and obese, defining different steroid hormones profiles depending on the obesity state. The role of circulating endocannabinoids in humans is still unclear, however there are several evidences concerning their involvement in obesity. In the second part of the thesis, we determined changes of circulating endocannabinoids in obese patients after a weight loss induced by bariatric surgery, currently the most effective long-term treatment for obesity, using LC/MS-MS. We measured basal and dynamic endocannabinoids plasma levels in 12 patients with severe obesity before, one month after and six months after the Roux-en-Y gastric bypass intervention, currently one of the most performed types of bariatric surgery. All together the findings illustrated in this thesis project will help better define the role of steroid hormones and endocannabinoids in the framework of obesity in humans and the role that each type of molecule might have in its pathophysiology.

Occupational sitting time and overweight and obesity in Australian workers

Background: One of the major immediate and long-term health issues in modern society is the problem of overweight and obesity. This paper examines the role of the workplace in the problem by studying the association between occupational sitting time and overweight and obesity (body mass index [BMI] >= 25) in a sample of adult Australians in full-time employment. Methods: Data on age, gender, occupation, physical activity, occupational sitting time, and BMI were collected in September 2003 from a sample of 1579 adult men and women in full-time employment at the time of the survey. Logistic regression was used to examine the association between occupational sitting time and overweight and obesity. Results: Mean occupational sitting time was > 3 hours/day, and significantly higher in men (209 minutes) than in women (189 minutes, p =0.026). Univariate analyses showed significant associations between occupational sitting time and BMI of >= 25 in men but not in women. After adjusting for age, occupation, and physical activity, the odds ratio for BMI >= 25 was 1.92 (confidence interval: 1.17-3.17) in men who reported sitting for > 6 hours/day, compared with those who sat for < 45 minutes/day. Conclusions: Occupational sitting time was independently associated with overweight and obesity in men who were in full-time paid work. These results suggest that the workplace may play an important role in the growing problem of overweight and obesity. Further research is needed to clearly understand the association between sitting time at work and over-weight and obesity in women.

Sexagem histológica e desempenho de Oreochromis niloticus testando diâmetros de ração de acordo com o aparato bucal

Estudou-se o tamanho da boca de larvas de tilápia-do-nilo e testou-se o efeito de diferentes granulometrias da ração sobre o ganho de peso, comprimento e sobrevivência das larvas aos 30 e 60 dias de arraçoamento. Avaliou-se também o método de sexagem por meio de microscopia de luz aos 35 dias de idade. A medida da boca das larvas apresentou valores médios de 918,2±152,9μm aos cinco dias de idade. de acordo com esse dado, testaram-se três granulometrias: 0,25, 0,35 e 0,50mm. Aos 30 e aos 60 dias de arraçoamento, 10% das larvas foram medidas, pesadas e contadas para cálculo da taxa de sobrevivência. O tamanho dos grânulos testados não afetou o desempenho das larvas de tilápia nilótica com alimentação iniciada aos cinco dias pós-eclosão. Quanto à sexagem histológica aos 35 dias de idade, as gônadas apresentaram-se, em sua maioria, indiferenciadas. Recomenda-se que essa análise deva ser realizada de acordo com o tamanho dos animais e não com a idade.

Barriers and facilitators to initial and continued attendance at community-based lifestyle programmes among families of overweight and obese children: a systematic review

The success of childhood weight management programmes relies on family engagement. While attendance offers many benefits including the support to make positive lifestyle changes, the majority of families referred to treatment decline. Moreover, for those who do attend, benefits are often compromised by high programme attrition. This systematic review investigated factors influencing attendance at community-based lifestyle programmes among families of over-weight or obese children. A narrative synthesis approach was used to allow for the inclusion of quantitative, qualitative and mixed-method study designs. Thirteen studies met the inclusion criteria. Results suggest that parents provided the impetus for programme initiation, and this was driven largely by a concern for their child's psychological health and wellbeing. More often than not, children went along without any real reason or interest in attending. Over the course of the programme, however, children's positive social experiences such as having fun and making friends fostered the desire to continue. The stigma surrounding excess weight and the denial of the issue amongst some parents presented barriers to enrolment and warrant further study. This study provides practical recommendations to guide future policy makers, programme delivery teams and researchers in developing strategies to boost recruitment and minimise attrition.

Level-one highest weight representation of U-q[sl((N)over-cap vertical bar 1)] and Bosonization of the multicomponent Super t-J model

We study the level-one irreducible highest weight representations of the quantum affine superalgebra U-q[sl((N) over cap\1)], and calculate their characters and supercharacters. We obtain bosonized q-vertex operators acting on the irreducible U-q[sl((N) over cap\1)] modules and derive the exchange relations satisfied by the vertex operators. We give the bosonization of the multicomponent super t-J model by using the bosonized vertex operators. (C) 2000 American Institute of Physics. [S0022- 2488(00)00508-9].

Do socioeconomic factors shape weight and obesity trajectories over the transition from midlife to old age? Results from the French GAZEL cohort study

BACKGROUND: Obesity is a contemporary epidemic that does not affect all age groups and sections of society equally. OBJECTIVE: The objective was to examine socioeconomic differences in trajectories of body mass index (BMI; in kg/m(2)) and obesity between the ages of 45 and 65 y. DESIGN: A total of 13,297 men and 4532 women from the French GAZEL (Gaz de France Electricité de France) cohort study reported their height in 1990 and their weight annually over the subsequent 18 y. Changes in BMI and obesity between ages 45 and 49 y, 50 and 54 y, 55 and 59 y, and 60 and 65 y as a function of education and occupational position (at age 35 y) were modeled by using linear mixed models and generalized estimating equations. RESULTS: BMI and obesity rates increased between the ages of 45 and 65 y. In men, BMI was higher in unskilled workers than in managers at age 45 y; this difference in BMI increased from 0.82 (95% CI: 0.66, 0.99) at 45 y to 1.06 (95% CI: 0.85, 1.27) at 65 y. Men with a primary school education compared with those with a high school degree at age 45 y had a 0.75 (95% CI: 0.51, 1.00) higher BMI, and this difference increased to 1.32 (95% CI: 1.03,1.62) at age 65 y. Obesity rates were 3.35% and 7.68% at age 45 y and 9.52% and 18.10% at age 65 y in managers and unskilled workers, respectively; the difference in obesity increased by 4.25% (95% CI: 1.87, 6.52). A similar trend was observed in women. Conclusions: Weight continues to increase in the transition between midlife and old age; this increase is greater in lower socioeconomic groups.

Development and validation of a risk score predicting substantial weight gain over 5 years in middle-aged European men and women.

BACKGROUND Identifying individuals at high risk of excess weight gain may help targeting prevention efforts at those at risk of various metabolic diseases associated with weight gain. Our aim was to develop a risk score to identify these individuals and validate it in an external population. METHODS We used lifestyle and nutritional data from 53°758 individuals followed for a median of 5.4 years from six centers of the European Prospective Investigation into Cancer and Nutrition (EPIC) to develop a risk score to predict substantial weight gain (SWG) for the next 5 years (derivation sample). Assuming linear weight gain, SWG was defined as gaining ≥ 10% of baseline weight during follow-up. Proportional hazards models were used to identify significant predictors of SWG separately by EPIC center. Regression coefficients of predictors were pooled using random-effects meta-analysis. Pooled coefficients were used to assign weights to each predictor. The risk score was calculated as a linear combination of the predictors. External validity of the score was evaluated in nine other centers of the EPIC study (validation sample). RESULTS Our final model included age, sex, baseline weight, level of education, baseline smoking, sports activity, alcohol use, and intake of six food groups. The model's discriminatory ability measured by the area under a receiver operating characteristic curve was 0.64 (95% CI = 0.63-0.65) in the derivation sample and 0.57 (95% CI = 0.56-0.58) in the validation sample, with variation between centers. Positive and negative predictive values for the optimal cut-off value of ≥ 200 points were 9% and 96%, respectively. CONCLUSION The present risk score confidently excluded a large proportion of individuals from being at any appreciable risk to develop SWG within the next 5 years. Future studies, however, may attempt to further refine the positive prediction of the score.