Background Maintenance of lean muscle mass and related strength is associated with lower risk for numerous chronic diseases of aging in women. Objective Our aim was to evaluate whether the association between dietary protein and lean mass differs by physical activity level, amino acid composition, and body mass index categories. Design We performed a cross-sectional analysis of a prospective cohort. Participants/setting Participants were postmenopausal women from the Womens Health Initiative with body composition measurements by dual-energy x-ray absorptiometry (n=8,298). Main outcome measures Our study measured percent lean mass, percent fat mass, and lean body mass index. Statistical analyses performed Linear regression models adjusted for scanner serial number, age, calibrated energy intake, race/ethnicity, neighborhood socioeconomic status, and recreational physical activity were used to determine the relationship between protein intake and body composition measures. Likelihood ratio tests and stratified analysis were used to investigate physical activity and body mass index as potential effect modifiers. Results Biomarker-calibrated protein intake was positively associated with percent lean mass; women in the highest protein quintile had 6.3 percentage points higher lean mass than the lowest quintile (P<0.001). This difference rose to 8.5 percentage points for physically active women in the highest protein quintile (P-interaction=0.023). Percent fat mass and lean body mass index were both inversely related to protein intake (both P<0.001). Physical activity further reduced percent fat mass (P-interaction=0.022) and lean body mass index (P-interaction=0.011). Leucine intake was associated with lean mass, as were branched chain amino acids combined (both P<0.001), but not independent of total protein. All associations were observed for normal-weight, overweight, and obese women. Conclusions Protein consumption up to 2.02 g/kg body weight daily is positively associated with lean mass in postmenopausal women. Importantly, those that also engage in physical activity have the highest lean mass across body mass index categories.

<p>Various factors, including low levels of physical activity (PA), and high consumption levels of sugar-sweetened drinks (SD), have been implicated in the general increase of fat mass (FM) levels seen in youth. <b>Purpose</b>: To determine if a significant relationship exists between fat mass (FM) and physical activity (PA) or sugar-sweetened drink (SD), in boys and girls, using longitudinal analysis. <b>Methods</b>: 105 boys and 103 girls were assessed repeatedly during childhood and adolescence, for a maximum of 7 years. Height was measured annually, as was fat free mass (FFM) and FM estimated by dual X-ray absorptiometry (DXA). PA was evaluated bi-annually using a questionnaire for children (PAQ-C/A: 1 low, 5 high), and SD was assessed using a 24-hour dietary intake questionnaire completed 1-4 times/year. Years from peak height velocity were used as a biological age indicator. Random effects models were used to analyze the data, subsequent to log linearization of the FM variable since it was not initially normally distributed. <b>Results</b>: The constructed model, controlling for maturation, FFM, and adjusted energy intake, found no interaction effect between SD and PA (p>0.05). After removal of the interaction term from the model, SD was found to have no significant relationship (p>0.05) with FM of boys or girls. In contrast, PA level was found to have a significant relationship (p<0.05) with FM of males; but not with FM of females. <b>Conclusion</b>: The longitudinal models employed revealed a significant negative relationship between level of PA and FM in males but not females, after controlling for maturational status, body size and dietary energy intake. This finding lends support, to proponents of increasing PA in youth to control FM. Regarding SD and FM, the models employed showed no relationship. Future investigation with more complex models, accounting for more covariates, may be warranted in this area.</p>

The metabolic syndrome has become a major public health challenge world-wide and, at least in the industrialized world, the prevalence of the metabolic syndrome is increasing. There is evidence to show that biological and lifestyle risk factors for metabolic syndrome are present in adolescence, which suggests that the antecedents of the disease may lie in early life. The period of adolescence is characterized by a decline in physical activity (PA; lack of PA is a lifestyle risk factor for metabolic syndrome) and an increase in fat mass deposition (a biological risk factor for metabolic syndrome). Therefore, investigating how the development of these two variables relates to adult cardiometabolic risk is important to fuel early intervention. A factor which has the potential to influence these two risk factors, and thus ultimately the metabolic syndrome, is the timing of biological maturity (i.e. whether an individual is early, average or late maturing when compared to peers of the same age). The influence of biological maturity has largely been overlooked in previous research; therefore, the general objective of this thesis was to investigate the associations between biological maturity, adolescent PA and fat mass development, and young adult cardiometabolic risk. Three studies were necessary to realize this objective, and together help to elucidate the role of biological maturity in the adolescent decline in physical activity, fat development, and the development of adult metabolic syndrome. Ultimately, this information will aid in the development and implementation of interventions to decrease prevalence of metabolic syndrome.<p> Study 1: The purpose of study 1 was to investigate whether observed gender differences in objectively measured PA in children (8 to 13 years) are confounded by biological maturity differences. Methods: Four hundred and one children (194 boys and 207 girls) volunteered for this study. An Actigraph accelerometer was used to obtain 7 consecutive days of minute-by-minute PA data on each participant. Minutes of moderate to vigorous PA per day (MVPA), continuous minutes of MVPA per day (CMVPA), and minutes of vigorous PA per day (VPA) were derived from the accelerometer data. Age at peak height velocity (APHV), an indicator of somatic maturity, was predicted and individuals aligned by this biological age (years from APHV). Gender differences in the PA variables were analyzed using a two-way (gender X age) ANOVA. Results: Levels of PA decreased with increasing chronological ages in both genders (p<0.05). When aligned on chronological age, boys had a higher MVPA at 10 through 13 years, a higher CMVPA at 9 through 12 years, and a higher VPA at 9 though 13 years (p<0.05). When aligned on biological age, PA declined with increasing maturity (p<0.05); however gender differences between biological age groups disappeared. Conclusion: The observed age-related decline in adolescent boys and girls PA is antithetical to public health goals and as such is an important area of research. In order to fully understand gender disparities in PA, consideration must be given to the confounding effects of biological maturity.<p> Study 2: Understanding the influence of biological age (BA) on the decline in PA would better inform researchers about the effective timing of intervention. The purpose of study 2 was to describe the PA levels and perceived barriers to PA of adolescent girls grouped by school grade and biological maturity status (i.e., early or late maturing) within grades. Methods: 221 girls (aged 8-16 years; grades 4-10) wore an Actical accelerometer for 7 days and then completed a semi-structured, open ended questionnaire on perceived barriers to PA over the 7 day period. Predicted APHV and recalled age at menarche were used to assess maturity among the elementary and high school girls, respectively. Maturity and grade group differences in PA were assessed using MANCOVA and independent sample t-test, and barriers to PA using chi squared statistics. Results: Daily minutes spent in MVPA decreased by 40% between grades 4 to 10. Within grade groupings, no differences in PA were found between early and late maturing girls (p>0.05). Grades 4-6 participants cited more interpersonal (i.e., social) barriers. Grades 9-10 participants cited more institutional barriers to PA, primarily revolving around the institution of school. No differences were found in types of barriers reported between early and late maturing girls. Conclusion: Since PA and types of perceived barriers to PA were dependent on grade, future research should work to identify the most salient (i.e., frequent and limiting) barriers to PA by chronological age in youth.<p> Study 3: Although the metabolic syndrome is thought to be mainly a consequence of obesity, the mechanisms underpinning its development are not that well understood. The purpose of study 3 was to examine total body fat mass (FM), trunk FM and PA developmental trajectories (aligned to BA; years from APHV) of individuals categorized as low and high for cardiometabolic risk at 26 years, while investigating biological and lifestyle risk factors. Methods: The sample were 55 males and 76 females from the Saskatchewan Pediatric Bone Mineral Accrual Study (1991-2007) who were assessed from childhood to young adulthood and had a measure of cardiometabolic risk at young adulthood (26.0 + 2.3 yrs). Height was measured biannually. Total body FM and trunk FM was assessed annually by dual energy-X-ray absorptiometry. PA and dietary intake was evaluated two to three times annually using surveys. Individuals were grouped into maturity status groups (early, average or late) depending on their APHV. Two composite cardiometabolic risk scores were calculated for males and females separately. The first was derived for a sub-sample (N=48) by summing the standardized residuals of inverted high-density lipoprotein cholesterol, homeostasis model assessment for insulin resistance, mean arterial pressure (MAP) and fasting triglyceride levels. A second score was derived for the whole sample by summing the standardized residuals for MAP. Scores for both samples were regressed on to age and adult smoking status. High and low cardiometabolic risk groups were determined based on a sex- specific median split of risk scores. Data were analyzed using random effects models. Models were built in a stepwise procedure with predictor variables added one at a time, using the log likelihood ratio statistic to determine if one model was a significant improvement over the previous one. Results: The final model indicated that once the independent effects of maturity (years from APHV) and height were controlled, the high risk group males and females had significantly (p<0.05) greater total body FM and trunk FM development at all ages. No association was found between young adult cardiometabolic risk and development of PA. Furthermore, in general, timing of biological maturity was not associated with development of PA or FM. Conclusion: Young adults at higher cardiometabolic risk have greater body fat as early as 8 years of age, which lends support to early intervention.<p> General Conclusions: Adolescence has been highlighted as a critical period for the development of adult disease, such as the metabolic syndrome. Results from this thesis support this contention by showing a decrease in PA (by both chronological and biological age) in males and females across adolescence. It further showed that an increase in total and central fatness during adolescence may be critical for the development of the metabolic syndrome in adulthood. Timing of biological maturity, in general, was not shown to have an independent impact on adolescent or young adult PA, adolescent perceived barriers to PA, fat mass development, or young adult cardiometabolic risk. However, further research is required before definitive conclusions can be made about the short and long term impacts of timing of biological maturity on health.

<p>Various factors, including low levels of physical activity (PA), and high consumption levels of sugar-sweetened drinks (SD), have been implicated in the general increase of fat mass (FM) levels seen in youth. <b>Purpose</b>: To determine if a significant relationship exists between fat mass (FM) and physical activity (PA) or sugar-sweetened drink (SD), in boys and girls, using longitudinal analysis. <b>Methods</b>: 105 boys and 103 girls were assessed repeatedly during childhood and adolescence, for a maximum of 7 years. Height was measured annually, as was fat free mass (FFM) and FM estimated by dual X-ray absorptiometry (DXA). PA was evaluated bi-annually using a questionnaire for children (PAQ-C/A: 1 low, 5 high), and SD was assessed using a 24-hour dietary intake questionnaire completed 1-4 times/year. Years from peak height velocity were used as a biological age indicator. Random effects models were used to analyze the data, subsequent to log linearization of the FM variable since it was not initially normally distributed. <b>Results</b>: The constructed model, controlling for maturation, FFM, and adjusted energy intake, found no interaction effect between SD and PA (p>0.05). After removal of the interaction term from the model, SD was found to have no significant relationship (p>0.05) with FM of boys or girls. In contrast, PA level was found to have a significant relationship (p<0.05) with FM of males; but not with FM of females. <b>Conclusion</b>: The longitudinal models employed revealed a significant negative relationship between level of PA and FM in males but not females, after controlling for maturational status, body size and dietary energy intake. This finding lends support, to proponents of increasing PA in youth to control FM. Regarding SD and FM, the models employed showed no relationship. Future investigation with more complex models, accounting for more covariates, may be warranted in this area.</p>

The metabolic syndrome has become a major public health challenge world-wide and, at least in the industrialized world, the prevalence of the metabolic syndrome is increasing. There is evidence to show that biological and lifestyle risk factors for metabolic syndrome are present in adolescence, which suggests that the antecedents of the disease may lie in early life. The period of adolescence is characterized by a decline in physical activity (PA; lack of PA is a lifestyle risk factor for metabolic syndrome) and an increase in fat mass deposition (a biological risk factor for metabolic syndrome). Therefore, investigating how the development of these two variables relates to adult cardiometabolic risk is important to fuel early intervention. A factor which has the potential to influence these two risk factors, and thus ultimately the metabolic syndrome, is the timing of biological maturity (i.e. whether an individual is early, average or late maturing when compared to peers of the same age). The influence of biological maturity has largely been overlooked in previous research; therefore, the general objective of this thesis was to investigate the associations between biological maturity, adolescent PA and fat mass development, and young adult cardiometabolic risk. Three studies were necessary to realize this objective, and together help to elucidate the role of biological maturity in the adolescent decline in physical activity, fat development, and the development of adult metabolic syndrome. Ultimately, this information will aid in the development and implementation of interventions to decrease prevalence of metabolic syndrome.<p> Study 1: The purpose of study 1 was to investigate whether observed gender differences in objectively measured PA in children (8 to 13 years) are confounded by biological maturity differences. Methods: Four hundred and one children (194 boys and 207 girls) volunteered for this study. An Actigraph accelerometer was used to obtain 7 consecutive days of minute-by-minute PA data on each participant. Minutes of moderate to vigorous PA per day (MVPA), continuous minutes of MVPA per day (CMVPA), and minutes of vigorous PA per day (VPA) were derived from the accelerometer data. Age at peak height velocity (APHV), an indicator of somatic maturity, was predicted and individuals aligned by this biological age (years from APHV). Gender differences in the PA variables were analyzed using a two-way (gender X age) ANOVA. Results: Levels of PA decreased with increasing chronological ages in both genders (p<0.05). When aligned on chronological age, boys had a higher MVPA at 10 through 13 years, a higher CMVPA at 9 through 12 years, and a higher VPA at 9 though 13 years (p<0.05). When aligned on biological age, PA declined with increasing maturity (p<0.05); however gender differences between biological age groups disappeared. Conclusion: The observed age-related decline in adolescent boys and girls PA is antithetical to public health goals and as such is an important area of research. In order to fully understand gender disparities in PA, consideration must be given to the confounding effects of biological maturity.<p> Study 2: Understanding the influence of biological age (BA) on the decline in PA would better inform researchers about the effective timing of intervention. The purpose of study 2 was to describe the PA levels and perceived barriers to PA of adolescent girls grouped by school grade and biological maturity status (i.e., early or late maturing) within grades. Methods: 221 girls (aged 8-16 years; grades 4-10) wore an Actical accelerometer for 7 days and then completed a semi-structured, open ended questionnaire on perceived barriers to PA over the 7 day period. Predicted APHV and recalled age at menarche were used to assess maturity among the elementary and high school girls, respectively. Maturity and grade group differences in PA were assessed using MANCOVA and independent sample t-test, and barriers to PA using chi squared statistics. Results: Daily minutes spent in MVPA decreased by 40% between grades 4 to 10. Within grade groupings, no differences in PA were found between early and late maturing girls (p>0.05). Grades 4-6 participants cited more interpersonal (i.e., social) barriers. Grades 9-10 participants cited more institutional barriers to PA, primarily revolving around the institution of school. No differences were found in types of barriers reported between early and late maturing girls. Conclusion: Since PA and types of perceived barriers to PA were dependent on grade, future research should work to identify the most salient (i.e., frequent and limiting) barriers to PA by chronological age in youth.<p> Study 3: Although the metabolic syndrome is thought to be mainly a consequence of obesity, the mechanisms underpinning its development are not that well understood. The purpose of study 3 was to examine total body fat mass (FM), trunk FM and PA developmental trajectories (aligned to BA; years from APHV) of individuals categorized as low and high for cardiometabolic risk at 26 years, while investigating biological and lifestyle risk factors. Methods: The sample were 55 males and 76 females from the Saskatchewan Pediatric Bone Mineral Accrual Study (1991-2007) who were assessed from childhood to young adulthood and had a measure of cardiometabolic risk at young adulthood (26.0 + 2.3 yrs). Height was measured biannually. Total body FM and trunk FM was assessed annually by dual energy-X-ray absorptiometry. PA and dietary intake was evaluated two to three times annually using surveys. Individuals were grouped into maturity status groups (early, average or late) depending on their APHV. Two composite cardiometabolic risk scores were calculated for males and females separately. The first was derived for a sub-sample (N=48) by summing the standardized residuals of inverted high-density lipoprotein cholesterol, homeostasis model assessment for insulin resistance, mean arterial pressure (MAP) and fasting triglyceride levels. A second score was derived for the whole sample by summing the standardized residuals for MAP. Scores for both samples were regressed on to age and adult smoking status. High and low cardiometabolic risk groups were determined based on a sex- specific median split of risk scores. Data were analyzed using random effects models. Models were built in a stepwise procedure with predictor variables added one at a time, using the log likelihood ratio statistic to determine if one model was a significant improvement over the previous one. Results: The final model indicated that once the independent effects of maturity (years from APHV) and height were controlled, the high risk group males and females had significantly (p<0.05) greater total body FM and trunk FM development at all ages. No association was found between young adult cardiometabolic risk and development of PA. Furthermore, in general, timing of biological maturity was not associated with development of PA or FM. Conclusion: Young adults at higher cardiometabolic risk have greater body fat as early as 8 years of age, which lends support to early intervention.<p> General Conclusions: Adolescence has been highlighted as a critical period for the development of adult disease, such as the metabolic syndrome. Results from this thesis support this contention by showing a decrease in PA (by both chronological and biological age) in males and females across adolescence. It further showed that an increase in total and central fatness during adolescence may be critical for the development of the metabolic syndrome in adulthood. Timing of biological maturity, in general, was not shown to have an independent impact on adolescent or young adult PA, adolescent perceived barriers to PA, fat mass development, or young adult cardiometabolic risk. However, further research is required before definitive conclusions can be made about the short and long term impacts of timing of biological maturity on health.

Due to the widespread use of the endocrine disruptors Bisphenol-A (BPA) and phthalates in many plastic consumer goods, medical equipment, and personal care products, more than 95% of the US population show detectable levels of urinary BPA and phthalate metabolites. Both have been linked to increased body mass index (BMI in kg/m2), an inexpensive diagnostic tool for obesity, which may however not reflect body fatness. Since excess body fat is associated with cardiovascular diseases, cancer and type II diabetes, it is important to understand the relationship between body fat composition and exposure to BPA and phthalates, a relationship that is still unknown. Using NHANES 1999-2006 data on adults aged >20 years, we investigated the relationship between urinary BPA (N=2,534), monoethyl-phthalate (mEP, N=5,431), monobutyl-phthalate (mBP), monoethylhexyl-phthalate (mEHP) and monobenzyl-phthalate (mBzP, each N=5,436) measured by high-performance liquid chromatography tandem mass spectrometry, and body fat composition measured as lean mass (LM, grams), fat mass (FM, grams) and percent body fat (%BF) using Dual Energy X-ray Absorptiometry. A multivariable linear regression analysis yielded that independently of BMI, BPA, mBP, and mBzP were inversely associated with LM (quartile 4 b=-862.16 (354.65), -731.76 (248.89), -909.13 (252.32), respectively; all p<0.02, p-trend<0.02); mEHP and FM were inversely associated (quartile 4 b=-297.98 (144.87), p=0.04, p-trend<0.02); BPA, mBP, and mBzP were positively associated with %BF but not clinically significant. These results provide novel insights in the relationship between urinary BPA, phthalates and LM independent of BMI, and it highlights the need for prospective studies establishing temporality of this relationship.

Title: Body analysis of street hockey players in categories U15-U18 Objectives: The main object of this thesis is to determine body analysis of street hockey players playing Extra League in categories younger and older juniors using bioelectrical impedance analysis. Measured data should be compared amonit groups of players aged 15 a 16, 16 and 17, 17 and 18. Methods: In the thesis are used sometometric methods to gather antropometrical parameters and also the bioelectrical impedance analysis of the body structure using the device Tanita BC 418 MA to determine body structures of individual players. Results: We measured and compared selected parameters of body structures of street hockey players (n = 101) in age groups of 15, 16, 17 and 18 years. The differences in the amount of body fat, body fat percentage, free fat mass and bodily fluids amonit individual groups of street hockey players were monitored. Body fat percentage and free fat mass do not depends on age. Amount of body fat and free fat mass depends on age. Ice hockey players are taller and have more fat free mass. In comparison with the antropological research of the players in the same age from the year 2001 we discovered, that present-day players are, on average, 3,68 cm shorter, but they are, on average, 1,5 kg heavier, which is caused...

A obesidade, caracterizada pelo excesso de tecido adiposo (TA), é uma doença epidêmica com crescente prevalência desde a infância. Os primeiros meses de vida são considerados críticos para o desenvolvimento humano devido a relação com repercussões duradouras na fisiologia do organismo. O TA tem sua formação desde a fase fetal e secreta inúmeras citocinas relacionadas com a obesidade. Destacam-se neste âmbito: a adiponectina, associada à sensibilidade a insulina; a leptina, pela sua interação com o dispêndio energético e a zinco-&#945;-glicoproteína (ZAG) devido à ação moduladora na expansão do TA. Conhecendo-se a importância da ação destas citocinas e a relevância dos primeiros meses de vida sobre a saúde do indivíduo, o objetivo deste estudo do tipo coorte foi analisar as concentrações de adiponectina, leptina e ZAG do cordão umbilical e relacionar com a composição corporal de lactentes do nascimento ao 4º mês de vida. As citocinas foram determinadas no sangue do cordão umbilical por ELISA. A composição corporal foi avaliada mensalmente pelo PEA POD® (Infant Body Composition, Cosmed, USA). Realizou-se análise de variância (ANOVA) para comparações de médias das variáveis qualitativas. A análise de regressão linear múltipla foi utilizada para determinar a relação entre as citocinas e a composição corporal. A adiponectina se associou inversamente com o percentual de gordura no 1º mês de vida em lactentes não alimentadas por leite materno. A leptina mostrou associação positiva com o percentual de massa gorda ao nascimento para o sexo feminino (R²=0,29; P=0.001), porém essa associação não se manteve significante após o primeiro mês de vida. No modelo final estratificado por sexo, a ZAG foi a única variável analisada que explicou o percentual de gordura no 3º mês (R²=0,21; P=0,003) e no 4º mês de vida (R²=0,14; P=0,03) para o sexo feminino. Os resultados desta investigação reforçam a possível influência positiva do papel da leptina no sangue do cordão umbilical no percentual de gordura ao nascimento e do papel da ZAG com influência negativa no percentual de gordura no 3º e 4º meses de vida. / Obesity, characterized by excess adipose tissue (AT), is an epidemic disease with increasing prevalence since childhood. The the first months of life are considered critical to human development because of the relationship with long-lasting effects on the physiology of the organism. The TA formation starts in fetal stage and secretes numerous cytokines related to obesity. Stand out in this context: adiponectin is associated with insulin sensitivity; leptin by its interaction with the energy expenditure and zinc-&#945;-glycoprotein due to their modulating effects of the expansion of the TA. Knowing the importance of the action of these cytokines and the relevance of the first months of life on the health of an individual, the aim of this cohort study was to analyze the concentrations of adiponectin, leptin and ZAG cord and relate to body composition of children from birth to 4 months of life. Cytokines were assayed in the cord blood by ELISA. Body composition was assessed by the PEA POD ® (Infant Body Composition, Cosmed, USA) monthly. An analysis of variance (ANOVA) for mean comparisons of qualitative variables. A multiple linear regression analysis was used to determine the relationship between the cytokines and body composition. Adiponectin was inversely associated with the percentage of fat in the 1st month of life in infants not being breast fed. Leptin was positively associated with the percentage of fat mass at birth for females (R ² = 0.29), but this association did not remain after the first month of life. In the final model stratified by sex, ZAG was the only variable that explained analyzed the percentage of fat in 3 (R ² = 0.21) and 4 months (R ² = 0.14) for females. The results of this study reinforce the positive influence of the role of leptin in umbilical cord blood for the percentage of fat at birth and the role of ZAG with negative influence on the percentage of fat in the third and fourth months of life.

A obesidade, caracterizada pelo excesso de tecido adiposo (TA), é uma doença epidêmica com crescente prevalência desde a infância. Os primeiros meses de vida são considerados críticos para o desenvolvimento humano devido a relação com repercussões duradouras na fisiologia do organismo. O TA tem sua formação desde a fase fetal e secreta inúmeras citocinas relacionadas com a obesidade. Destacam-se neste âmbito: a adiponectina, associada à sensibilidade a insulina; a leptina, pela sua interação com o dispêndio energético e a zinco-&#945;-glicoproteína (ZAG) devido à ação moduladora na expansão do TA. Conhecendo-se a importância da ação destas citocinas e a relevância dos primeiros meses de vida sobre a saúde do indivíduo, o objetivo deste estudo do tipo coorte foi analisar as concentrações de adiponectina, leptina e ZAG do cordão umbilical e relacionar com a composição corporal de lactentes do nascimento ao 4º mês de vida. As citocinas foram determinadas no sangue do cordão umbilical por ELISA. A composição corporal foi avaliada mensalmente pelo PEA POD® (Infant Body Composition, Cosmed, USA). Realizou-se análise de variância (ANOVA) para comparações de médias das variáveis qualitativas. A análise de regressão linear múltipla foi utilizada para determinar a relação entre as citocinas e a composição corporal. A adiponectina se associou inversamente com o percentual de gordura no 1º mês de vida em lactentes não alimentadas por leite materno. A leptina mostrou associação positiva com o percentual de massa gorda ao nascimento para o sexo feminino (R²=0,29; P=0.001), porém essa associação não se manteve significante após o primeiro mês de vida. No modelo final estratificado por sexo, a ZAG foi a única variável analisada que explicou o percentual de gordura no 3º mês (R²=0,21; P=0,003) e no 4º mês de vida (R²=0,14; P=0,03) para o sexo feminino. Os resultados desta investigação reforçam a possível influência positiva do papel da leptina no sangue do cordão umbilical no percentual de gordura ao nascimento e do papel da ZAG com influência negativa no percentual de gordura no 3º e 4º meses de vida. / Obesity, characterized by excess adipose tissue (AT), is an epidemic disease with increasing prevalence since childhood. The the first months of life are considered critical to human development because of the relationship with long-lasting effects on the physiology of the organism. The TA formation starts in fetal stage and secretes numerous cytokines related to obesity. Stand out in this context: adiponectin is associated with insulin sensitivity; leptin by its interaction with the energy expenditure and zinc-&#945;-glycoprotein due to their modulating effects of the expansion of the TA. Knowing the importance of the action of these cytokines and the relevance of the first months of life on the health of an individual, the aim of this cohort study was to analyze the concentrations of adiponectin, leptin and ZAG cord and relate to body composition of children from birth to 4 months of life. Cytokines were assayed in the cord blood by ELISA. Body composition was assessed by the PEA POD ® (Infant Body Composition, Cosmed, USA) monthly. An analysis of variance (ANOVA) for mean comparisons of qualitative variables. A multiple linear regression analysis was used to determine the relationship between the cytokines and body composition. Adiponectin was inversely associated with the percentage of fat in the 1st month of life in infants not being breast fed. Leptin was positively associated with the percentage of fat mass at birth for females (R ² = 0.29), but this association did not remain after the first month of life. In the final model stratified by sex, ZAG was the only variable that explained analyzed the percentage of fat in 3 (R ² = 0.21) and 4 months (R ² = 0.14) for females. The results of this study reinforce the positive influence of the role of leptin in umbilical cord blood for the percentage of fat at birth and the role of ZAG with negative influence on the percentage of fat in the third and fourth months of life.

Being able to effectively match energy intake to energy expenditure (EE) is an important aspect in preventing weight re-gain in the post-obese. Although it is generally agreed upon that resting EE decreases concomitantly with weight loss, there is no set standard comparing the deviations with differing weight loss protocols and additionally, controversy remains as to whether this decrease is greater than can predicted. In order to address these issues 2977 subjects were analyzed using a systematic review and the differences of both the protocol and length of various interventions in addition to sex were compared. Next, data was selected from this systematic review and 815 subjects were analyzed for weight loss-induced changes in resting EE, FM and FFM. Another subgroup of studies (n = 1450) was analyzed and compared against the Harris-Benedict prediction equation to determine whether the changes in resting EE were greater than what was expected. Finally, in order to determine which factors may be involved in regulating changes in resting EE during weight loss, a secondary analysis was performed on 28 post-menopausal women (age= 50.4 ± 2.0 yrs; BMI= 32.4 ± 5.2 kg/m²) who were submitted to a 6-month caloric restriction. Body composition (DXA), resting EE (indirect calorimetry), physical activity EE (PAEE) and total EE (TEE) (doubly-labelled water) were measured before and after the 6 month weight loss. Blood samples were collected before and after to measure leptin and peptide YY. The results indicate that there was indeed a depression in resting EE during weight loss regardless of the type of intervention utilized. Furthermore, these findings suggest that the changes could not fully be explained by changes of FM and FFM alone and that leptin may be an important contributor to the changes of resting EE during weight loss.