Underweight Subjects Research Articles

The Relationship between Body Mass Index and Body Size Dissatisfaction in Young Adolescents: Spline Function Analysis

This study assessed how body size dissatisfaction (BSD) varies in relationship to specific body mass index (BMI) values in a sample of preadolescents. A novel statistical approach based on spline function, suitable to assess in detail how two variables are related, was used. The study was conducted between December 2004 and March 2005. Students (aged 11 to 14 years) from seven selected secondary schools in Verona, Italy, were invited to participate. The final study group included 678 subjects. BSD was assessed using the Body Image Assessment Procedure. BMI values were expressed as z scores. It was found that, in the total sample, slightly underweight subjects (BMI z scores=−0.5) had no BSD. BSD progressively increased (current body size > ideal body size) for BMI z scores >−0.5 and became negative (ideal body size > current body size) for BMI z scores <−0.5. In boys, average weight subjects had no BSD. BSD progressively increased for BMI z scores >0 and became negative for BMI z scores <0. In girls, moderately underweight subjects (BMI z scores=−1) had no BSD. BSD progressively increased for BMI z scores >−1 and became negative for BMI z scores <−1. Although sex significantly moderated the relationship between BMI and BSD ( P<0.001), socioeconomic status did not ( P=0.459). Because average weight and slightly underweight young girls desired a thinner body, our study suggests that these subgroups should receive particular attention in public health programs as well as in dietetics clinical practice.

High frequency of psychopathology in subjects wishing to lose weight: an observational study in Italian subjects

To investigate the frequency of psychiatric disorders in subjects wishing to lose weight categorized according to BMI. Cross-sectional study. An academic outpatient clinical nutrition service in Italy. A total of 207 subjects (thirty-nine men and 168 women; mean age: 38·7 (sd 14·1) years) consecutively attending the study centre for the first time between January 2003 and December 2006. In the entire study group, eighty-three (40 %) subjects had a psychiatric disorder according to criteria of the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision. Eating disorders were the most prevalent psychiatric condition (thirty-six subjects, 17·4 %), followed by mood and anxiety disorders (9·7 % and 8·7 %, respectively). The frequency of psychiatric disorders among different BMI categories was as follows: 75·0 % in underweight, 50·0 % in normal weight, 33·3 % in overweight and 33·3 % in obese subjects. Psychiatric disorders may be frequently found in subjects wishing to lose weight. Our results highlight the importance of psychiatric assessment especially in underweight and normal-weight subjects.

Association of gamma-glutamyltransferase with incidence of type 2 diabetes in Japan

The aim of this research was to examine the association of gamma-glutamyltransferase (GGT) and its interactions with alcohol consumption (alcohol), body mass index (BMI) and/or alanine aminotransferase (ALT) on the incidence of type 2 diabetes (DM) in Japan. Data from annual health examinations obtained from 1995 to 2005 were analyzed. The total number of subjects in this cohort was 39,563. Hazard ratios (HRs) were calculated by Cox regression analysis. GGT levels were positively associated with the incidence of DM in both men and women, after adjustment for several variables, including alcohol, BMI and ALT. Among women, the association was stronger in non-drinkers than in drinkers due to a significant interaction of GGT and alcohol. In non-drinkers, the HRs of the third and fourth GGT quartiles in women and the fourth GGT quartile in men were significantly higher than those of the first GGT quartile. The association between BMI and the incidence of DM was enhanced by increased GGT levels in women. When GGT levels were in the second to fourth quartiles, the HRs of obese subjects were significantly higher than those of underweight subjects. Conversely, obesity was no longer a significant risk factor for DM when GGT level was in the first quartile. Increased GGT levels were associated with the development of DM after adjustment for several possible confounding factors. The association between GGT and DM in non-drinkers was significantly stronger than that in drinkers. Furthermore, in women, obesity is no longer a risk factor for DM when GGT level is low.

Further exploration of the possible influence of polymorphisms in HTR2C and 5HTT on body weight

Receptors of the 5-HT2C subtype are of importance for the influence of serotonin on food intake, and 2 single nucleotide polymorphisms in this gene ( HTR2C)—Cys23Ser ( rs6318) and −759C>T ( rs3813929)—have been reported to be associated with weight and/or antipsychotic-induced weight gain. The present study aimed to replicate these associations; in addition, the 5-HTTLPR polymorphism in the promoter region of the serotonin transporter gene ( SLC6A4) was assessed. The polymorphisms were genotyped in subjects recruited from the normal population (n = 510), and possible associations between genotype and body mass index (BMI) were assessed. The Ser23 allele was more common in underweight subjects (BMI <20) than in normal- and overweight (BMI ≥20) subjects ( P = .006). The T allele of the −759C/T polymorphism was less common in the overweight group (BMI ≥25) ( P = .007). Homozygosity for the short allele of 5-HTTLPR was more frequent in underweight subjects ( P = .015). Our results are in agreement with previous studies, suggesting polymorphisms in HTR2C to be associated with body weight, particularly in women; and they also suggest that 5-HTTLPR may influence this phenotype. Further studies on the importance of the investigated genes for eating disorders and drug-induced weight gain are warranted.

The Concepts of Weight Control and Dietary Behavior in High School Seniors

The purpose of this study was to identify the concepts of body image, weight control and food behavior in 520 Korean high school seniors from Seoul and Gyeonggi Province. A questionnaire survey was conducted to investigate body image, concern of weight control, experience of weight control, the first time to try weight control, plan for weight control, reasons of weight control and food behaviors related with weight control. Anthropometric parameters such as weight and height were measured. Finally, data from 497 high school seniors were used for statistical analysis. The results were as follows. Many subjects had misperceptions. Among the subjects who perceived themselves as ‘fat’, 57.8% were normal weight and 0.5% underweight. Among the subjects who perceived themselves as ‘thin’, 59.5% were normal weight, 0.9% overweight and 0.9% obese. Girls were more concerned about weight control than boys (4.20 vs. 3.66). Weight loss had been experienced by 61.5% of the subjects and weight gain by 12.8%. First weight control was attempted by 71.3% of the subject at high school and by 28.7% at middle school. The majority of subjects planned for weight control before their freshman year. The boys choose ‘health’ as the primary reason for weight control, whereas the girls chose ‘good appearance’. The total score of food behaviors varied significantly according to BMI. Overweight and obese subjects had more desirable food behaviors than normal weight and underweight subjects (24.00, 24.06 vs. 21.92, 21.52). However, total scores of food behaviors showed no variation according to sex, weight control attempt and body image. In conclusion, the high school seniors had misconceptions about body image and weight control. They were exposed to a high risk of inappropriate weight control and food behaviors. Therefore, proper nutritional education programs need to be developed for high school seniors to prevent nutrition problems related to weight control and to maintain desirable food behaviors. (Korean J Nutr 2010; 43(6): 607 ~ 619)

Overestimation of own body weights in female university students: associations with lifestyles, weight control behaviors and depression

The study aimed to analyze the lifestyles, weight control behavior, dietary habits, and depression of female university students. The subjects were 532 students from 8 universities located in 4 provinces in Korea. According to percent ideal body weight, 33 (6.4%), 181 (34.0%), 283 (53.2%), 22 (4.1%) and 13 (2.5%) were severely underweight, underweight, normal, overweight and obese, respectively, based on self-reported height and weight. As much as 64.1% and only 2.4%, respectively, overestimated and underestimated their body weight status. Six overweight subjects were excluded from overestimation group for the purpose of this study, resulting in overestimation group consisting of only underweight and normal weight subjects. Compared to those from the normal perception group, significantly more subjects from the overestimation group were currently smoking (P = 0.017) and drank more often than once a week (P = 0.015), without any significant differences in dietary habits. Despite similar BMIs, subjects who overestimated their own weight statuses had significantly higher weight dissatisfaction (P = 0.000), obesity stress (P = 0.000), obsession to lose weight (P = 0.007) and depression (P = 0.018). Also, more of them wanted to lose weight (P = 0.000), checked their body weights more often than once a week (P = 0.025) and had dieting experiences using 'reducing meal size' (P = 0.012), 'reducing snacks' (P = 0.042) and 'taking prescribed pills' (P = 0.032), and presented 'for a wider range of clothes selection' as the reason for weight loss (P = 0.039), although none was actually overweight or obese. Unlike the case with overestimating one's own weight, being overweight was associated with less drinking (P = 0.035) and exercising more often (P = 0.001) and for longer (P = 0.001) and healthier reasons for weight control (P = 0.002), despite no differences in frequency of weighing and depression. The results showed that weight overestimation, independent of weight status, is associated with risky lifestyles, weight control behaviors, and mental conditions. Preventive interventions should focus not only on obesity, but also on body weight overestimation.

Study on the relationship between body mass index and health-related quality of life in middle-aged or older Chinese adults

To study the association between body mass index (BMI) and the health-related quality of life (HRQOL) in the middle-aged and older Chinese people. Data of 9539 middle-aged and older adults was collected from a cross-sectional survey performed in 9 provinces of China (Jiangsu, Anhui, Gansu, Qinghai, Fujian, Beijing, Jilin, Jiangxi and Henan province). MOS SF-36 was used to measure HRQOL. BMI classification was in accordance with the criteria recommended by the Ministry of Health of China. Rank sum test was used to compare HRQOL between subjects with normal weight and those with different BMI classification. Multiple logistic regression analysis was used to assess the association of HRQOL with BMI after adjusted for sex, age, marital, education, physical activity status and chronic diseases. When compared with middle-aged and older adults at normal weight range (18.5< or =BMI<24), data on physical domain (P<0.001), mental domain (P< 0.01) and 8 dimensions of HRQOL (physical functioning, mental health, P<0.05; role-physical, bodily pain, general health, vitality, social functioning, role-emotional, P<0.01) among subjects with underweight (BMI<18.5) were significantly lower while mental component summary (P<0.05) of overweight subjects (24< or =BMI<28) was significantly higher. Obese subjects (BMI> or =28) had worse physical function (physical functioning, P<0.01) but better mental health (mental health, P<0.01; mental component summary, P<0.05). After adjusting for other factors, and compared to middle aged and older adults with normal weight, data on odds ratios (ORs) of impaired HRQOL in physical domain (OR=1.67, 95% CI: 1.35-2.06), mental domain (OR=1.39, 95% CI: 1.13-1.70) and 8 dimensions increased among underweight subjects while ORs of impaired HRQOL in mental domain (OR=0.86, 95% CI: 0.78-0.95) and role-physical, vitality, social functioning, role-emotional and mental health dimensions decreased among overweight subjects. ORs increased (OR= 1.51, 95% CI: 1.27-1.80) in impaired HRQOL in physical functioning dimension but decreased in mental domain (OR=0.71, 95% CI: 0.60-0.85) as well as vitality, role-emotional and mental health dimensions among obese subjects. HRQOL of each domain were different among middle aged and older adults with different BMI classification. Underweight people had poor HRQOL in both physical domain and psychological domain, and obese people had poor physical function but good mental health condition.

Effect of iron ... zinc fortified milk on iron status and functional outcomes in underweight children

Background Iron and zinc are essential micronutrients duringschool-age period. Milk could be an alternative medium formineral fortification because it is consumed frequently bychildren.Objective To evaluate the effect of iron-zinc fortified milksupplementation on iron status and functional outcomes inunderweight children.Methods 44 2 underweight subjects aged 7-10 years attending 10primary schools in Jakarta and Solo were recruited in the study.Subjects who had chronic illnesses, severe anemia, thalassemiaor cow's milk allergy were excluded. Blood samples were analyzedto determine hemoglobin, serum ferritin and serum zinc. SerumCRP was measured in sub sampled subjects (n= 60). Subjectswere randomizedly allocated to receive iron-zinc fortified milk(n = 225) and standard milk (n = 217) for six months. The fortifiedmilk will provide additional6.3 mg iron and 1.5 mg zinc per day (2feeds). The main outcomes measured were iron status, cognitivefunction, growth, physical fitness and morbidity.Results Study groups were comparable at baseline. The fortifiedmilk group had better physical fitness score and exercise durationat baseline. Both milk supplementations reduced the prevalenceof anemia and iron deficiency. Fortified milk improved the speedprocessing score (P&lt; 0.0001), height (P&lt;0.0001) and sittingheight (P=O.Ol) significantly.Conclusion Supplementation of milk reduces the prevalence ofanemia and iron deficiency. Zinc-iron fortified milk gives positiveimpact on cognitive performance, growth, and physical fitness.

Vitamin and mineral supplement use by children and adolescents in the 1999-2004 National Health and Nutrition Examination Survey: relationship with nutrition, food security, physical activity, and health care access.

To determine if vitamin and mineral supplement use among children and adolescents in the United States is associated with nutrition, food security, physical activity, and health care access. Secondary analysis of nationally representative data from the 1999-2004 National Health and Nutrition Examination Survey. Questionnaires, household interviews, and medical examinations. Children and adolescents 2 to 17 years of age (N = 10 828). Vitamin and mineral supplement use in the past month. Demographics, nutrition, food security, physical activity, and health care access. Approximately 34% (SE 1.2) used vitamin and mineral supplements in the past month, with underweight subjects reporting greater intake. Younger age, non-Hispanic white race/ethnicity, being born in the United States, higher milk intake, lower total fat and cholesterol intake, higher dietary fiber intake, higher income, greater food security, lower media/computer use, greater physical activity, lower body mass index, health insurance coverage, better health care access, and better self-reported health were associated with greater use of vitamin and mineral supplements. Such supplements contributed significantly to total daily dietary intakes of vitamins and minerals. A large number of US children and adolescents use vitamin and mineral supplements, which for most may not be medically indicated. Such supplements contribute significantly to total dietary intakes of vitamins and minerals, and studies of nutrition should include their assessment. Since vitamin and mineral supplement users report greater health care access, health care providers may be in a position to provide screening and counseling regarding dietary adequacy and indications for supplement use.

Role of lean body mass for estimation of glomerular filtration rate in patients with chronic kidney disease with various body mass indices

Glomerular filtration rate (GFR) is the main tool used to diagnose, treat and follow up renal diseases. Age, gender, ethnicity and obesity all affect the relationship between serum creatinine, muscle mass/body weight and GFR. This study aimed to investigate the role of lean body mass for GFR estimation in patients with chronic kidney disease (CKD) with various body mass indices. In total, 110 Caucasian adult subjects with CKD referred for GFR measurement by (99m)Tc-DTPA renography were enrolled in the study. The patients were categorized according to body mass index values: <18.5 kg/m(2) (underweight), 18.5-24.9 kg/m(2) (normal), 25-29.9 kg/m(2) (overweight) and >30 kg/m(2) (obese). Lean body mass (LBM) and fat mass were measured by leg-to-leg bioimpedance. Predictive factors were identified by linear regression analysis in each group. GFR measured by DTPA, creatinine clearance, Cockcroft and Gault, and Modification of Diet in Renal Disease (four-variable) equations was 37+/-27, 42+/-30, 42+/-27, and 49+/-35 ml/min/1.73 m(2), respectively. The predictive role of 1/SCr, age, serum albumin, amount of proteinuria, LBM and fat mass was investigated all groups. None of the factors was significant in underweight and healthy weight groups except for 1/serum creatinine (SCr). LBM/SCr was an independent predictive factor for both overweight and obese groups. 1/SCr accounted for 96.2% of the variability in measured GFR for underweight subjects but only 58.1% of the variability in GFR of obese subjects. The formulae derived from SCr should be used cautiously in overweight and obese subjects. LBM measured by bioimpedance was an independent predictive factor of GFR in obese/overweight subjects and added clinically important diagnostic value to 1/SCr. It needs to be investigated as a parameter in further studies attempting to develop formulae for estimating GFR in larger obese and overweight populations.

Ghrelin/obestatin ratio in two populations with low bodyweight: Constitutional thinness and anorexia nervosa

Constitutional thinness (CT) and anorexia nervosa (AN) are two categories of severely underweight subjects. Some appetite-regulating hormones display opposite levels in AN and CT. While levels of ghrelin, an orexigenic hormone, fit with the normal food intake in CT, the lack of efficacy of increased ghrelin levels in AN is not clear. Obestatin is a recently described peptide derived from the preproghrelin gene, reported to inhibit appetite in contrast to ghrelin. The aim of this study was to determine whether the circadian profile of obestatin, total and acylated ghrelin levels is different in CT subjects when compared with AN patients. Six-points circadian profiles of plasma obestatin, acylated ghrelin, total ghrelin and other hormonal and nutritional parameters were evaluated in four groups of young women: 10 CT, 15 restricting-type AN, 7 restored from AN and 9 control subjects. Obestatin circadian levels were significantly higher in AN (p<0.0001) while no difference was found between CT and control subjects. Acylated and total ghrelin were found increased in AN. Acylated ghrelin/obestatin and total ghrelin/obestatin were found decreased in AN compared to CT or C subjects (p<0.05). The percentage of acylated ghrelin was found decreased in CT group (p<0.05). The decreased ghrelin/obestatin ratio found in AN might participate in the restraint in nutriment intake of these patients. In contrast, in CT a lower percentage of acylated over total ghrelin might be considered in the aetiology of this condition.

Obesity, Inflammation and Metabolic Disorders

The incidence of obesity worldwide has increased drastically during recent decades. Currently, obesity is viewed as a pro-inflammatory state with a rise in inflammatory parameters such as C-reactive protein (CRP), nitric oxide (NO) along with the increase in the secretion of leptin. Evaluation of these parameters in lean and obese subjects might enable us to understand the link between obesity, BMI and inflammation. In this connection, we have estimated serum leptin, CRP, NO, serum triglycerides, cholesterol, and lipid profile in normal, underweight, overweight and obese subjects. Interestingly leptin level is found to be higher in obese and overweight subjects. A profound positive correlation has been observed between obesity, serum leptin and CRP suggesting a possible link between obesity, inflammation and metabolic syndrome.

Reference values of handgrip dynamometry of healthy adults: A population-based study

Although maximal voluntary handgrip strength (HGS) is considered a reliable tool in nutritional assessment there are few reference data available. This paper presents reference values for handgrip strength of healthy adults (age > or = 20 years) from a household survey. Data were obtained from a representative sample of adults (1122 males and 1928 females) living in Niterói, Rio de Janeiro, Brazil. HGS was measured three times with a Jamar mechanical dynamometer in both hands and the highest value used in the analysis. The percentile distribution of HGS was calculated according to sex and age categories. Mean values of right and left HGS were 42.8 and 40.9 kg for males, and 25.3 and 24.0 kg for females, respectively. HGS increased with age and significantly decreased after 40 and 50 year-olds for women and men, respectively. Body mass index (BMI) was associated with HGS in both sexes but only underweight male subjects had significantly lower HGS values. The highest HGS values are observed at the 4th decade of life with significant declines thereafter. HGS is significantly associated with BMI. The reference values of HGS may be useful in assessing the nutritional status of similar adult urban population.

The Association of Body Mass Index with Health-Related Quality of Life: An Exploratory Study in a Multiethnic Asian Population

Objectives To evaluate the association between body mass index (BMI) and health-related quality of life (HRQoL) in a multiethnic Asian population in Singapore, and to explore if the World Health Organization (WHO) recommendation of alternative BMI cutoffs for Asians could be further strengthened by evidence of higher risk of impaired HRQoL using these criteria. Methods Consenting English, Chinese, Malay and Tamil-speaking primary care patients (age ≥ 21 years) were interviewed using English/their respective mother tongue versions of the EQ-5D/EQ-VAS, Health Utilities Index (HUI2 & HUI3) and the SF-6D. We first evaluated the relationship between BMI and HRQoL (overall and individual attributes for each instrument) using multiple linear/logistic regression (where appropriate) to adjust for factors known to affect HRQoL. We next reorganized BMI into five categories (reflecting the differences in cutoffs between International/Asian classifications) and evaluated if median HRQoL scores were significantly different across these categories. Results Among 411 participants [response rate: 87%; median age: 51 years; obese: 19% (International); 33% (Asian)], after adjusting for sociodemographic and other factors, a tendency for underweight and obese subjects to report lower overall HRQoL scores was observed for most instruments. At the individual attribute level, obese subjects reported significantly lower HUI2 pain scores (regression coefficient: −0.035, P = 0.029) and greater odds of reporting problems for SF-6D role-limitations (odds ratio: 2.9, P = 0.005). Median overall HRQoL scores were not significantly different across the five BMI categories. Conclusion Consistent with available studies, obese subjects reported worse HRQoL than normal-weight subjects. That underweight subjects also reported worse HRQoL is interesting and requires confirmation. HRQoL was similar in Asians using either WHO criteria.

Trends of Waist Circumference Distribution and Abdominal Adiposity among Chinese Adults, 1993‐2004

Waist circumference (WC) is a strong predictor of hypertension and other noncommunicable diseases in China. This study examines temporal trends in waist circumference and the prevalence of abdominal adiposity trends among Chinese adults aged 20–65 from 1993 to 2004. We use data of the China Health and Nutrition Survey collected in 1993, 1997, 2000 and 2004. Compared with 1993, the 2004 waist circumference distribution curves flattened and shifted rightwards in males and females. Mean waist circumference increased from 76.8cm to 82.8cm among males and from 75.1cm to 79.3cm among females. A gradient of increasing prevalence of abdominal obesity was also observed in males and females. Similar trends of increasing waist circumference and abdominal obesity were observed in underweight, normal weight, overweight and obesity subjects defined by WHO recommended cutoff points of body mass index (BMI). These results demonstrate the rapid increase in obesity, especially abdominal obesity, among Chinese adults. Primary prevention of abdominal obesity should be a major public health problem in China.

Epidemiological evidence of altered cardiac autonomic function in overweight but not underweight subjects

Little is known about the altered cardiac autonomic function (CAF) across different levels of body mass index (BMI), including underweight, normal weight, overweight and obesity. This study provides a thorough analysis to clarify the CAF change in subjects with underweight, overweight and obesity. According to the World Health Organization (WHO) Asia-Pacific BMI cutoffs, a total of 1437 participants were classified as underweight (n=74), normal weight (n=588), overweight (n=313), obesity I (n=390) and obesity II (n=72). CAF was determined by standard deviation of normal-to-normal (SDNN) intervals or RR intervals, power spectrum in low (LF) and high frequency (HF) (LF, 0.04-0.15 Hz; HF, 0.15-0.40 Hz), and LF/HF ratio at supine for 5 min, the ratio between the 30th and the 15th RR interval after standing from the supine position (30/15 ratio) and the average heart-rate change while taking six deep breaths in 1 min (HR(DB)). There were significant differences in age, gender, socioeconomic status, blood pressure, HOMA insulin resistance index, fasting glucose, cholesterol, triglyceride and high-density lipoprotein (HDL)-C, and the prevalence of hypertension, ischemic/left bundle branch block (LBBB) electrocardiography (EKG) pattern, current smoking and alcohol use among subjects with underweight, normal weight, overweight, obesity I and II. Univariate analysis showed that SDNN, HR(DB), HF power and the square root of the LF/HF ratio differed among these five groups. Multivariate analysis showed that obesity I and II were inverse correlates of HR(DB) and HF power. Overweight, obesity I and II were positively associated with the square root of the LF/HF ratio. No BMI status was related to SDNN, 30/15 ratio or LF power. Underweight was not the independent correlate of any CAF indices. The risk for altered CAF is significant in overweight and obese subjects, independent of cardiovascular risk factors. Underweight is not apparently associated with CAF change.

Changes in energy expenditure associated with ingestion of high protein, high fat versus high protein, low fat meals among underweight, normal weight, and overweight females

BackgroundMetabolic rate is known to rise above basal levels after eating, especially following protein consumption. Yet, this postprandial rise in metabolism appears to vary among individuals. This study examined changes in energy expenditure in response to ingestion of a high protein, high fat (HPHF) meal versus an isocaloric high protein, low fat (HPLF) meal in underweight, normal weight, or overweight females (n = 21) aged 19–28 years.MethodsEnergy expenditure, measured using indirect calorimetry, was assessed before and every 30 minutes for 3.5 hours following consumption of the meals on two separate occasions. Height and weight were measured using standard techniques. Body composition was measured using bioelectrical impedance analysis.ResultsSignificant positive correlations were found between body mass index (BMI) and baseline metabolic rate (MR) (r = 0.539; p = 0.017), between body weight and baseline MR (r = 0.567; p = 0.011), between BMI and average total change in MR (r = 0.591; p = 0.008), and between body weight and average total change in MR (r = 0.464; p = 0.045). Metabolic rate (kcal/min) was significantly higher in the overweight group than the normal weight group, which was significantly higher than the underweight group across all times and treatments. However, when metabolic rate was expressed per kg fat free mass (ffm), no significant difference was found in postprandial energy expenditure between the overweight and normal groups. Changes in MR (kcal/min and kcal/min/kg ffm) from the baseline rate did not significantly differ in the underweight (n = 3) or in the overweight subjects (n = 5) following consumption of either meal at any time. Changes in MR (kcal/min and kcal/min/kg ffm) from baseline were significantly higher in normal weight subjects (n = 11) across all times following consumption of the HPHF meal versus the HPLF meal.ConclusionThere is no diet-induced thermogenic advantage between the HPHF and HPLF meals in overweight and underweight subjects. In contrast, in normal weight subjects, ingestion of a HPHF meal significantly increases MR (69.3 kcal/3.5 hr) versus consumption of a HPLF meal and provides a short-term metabolic advantage.

Height and body mass index in young adulthood and risk of schizophrenia: a longitudinal study of 1 347 520 Swedish men

Measures of body size reflect genetic and environmental influences on growth and energy balance. Associations between such measures and risk of schizophrenia have been inconsistent. This is a population-based cohort study of 1 347 520 men born in Sweden from 1952 to 1982, with height and body mass index (BMI) data available from conscription records. The Swedish National Hospital Discharge Register was used to identify subjects diagnosed with schizophrenia from 1970 to 2000. Subjects with lower BMI and shorter height had an increased risk of developing schizophrenia. Underweight subjects had an approximately 30% increase in risk compared with normal BMI subjects (adjusted HR = 1.30, 95% CI: 1.20-1.42). Tall subjects had an approximately 15% reduction in risk compared with short subjects (adjusted HR = 0.85, 95% CI: 0.80-0.92). Both height and BMI in early adulthood are strongly and inversely associated with risk of schizophrenia. We discuss these findings in relation to possible genetic and nutritional causal mechanisms.

Possible correlation of leptin with body fat distribution and adiposity: Evaluation of serum leptin in South Indian population.

Background: Leptin, an adipocyte-derived hormone, is known to play an important role in body fat. Gender, age, degree of obesity and sex steroids are expressed differentially in men and women. Methods: We measured serum leptin, testosterone and β-estradiol concentration by radioimmunoassay in 300 subjects (60 normal weight, 60 underweight, 60 overweight, 60 obese and 60 morbidly obese) by age group (18-40years and 41-62years), using full-length recombinant human leptin as a standard. Results: The present study found that morbidly obese and obese men and women older than 50years had 50-70% higher body mass index (BMI)-adjusted leptin levels than younger subjects. In addition, obese and underweight subjects showed a tendency towards lower BMI-adjusted leptin levels in younger than older, in both men and women subjects. Multiple regression analysis showed that age was positively correlated with leptin in both genders, even if the slope of rise was twice as high in women than in men. Together, these results indicate that in both genders, most prominently in females, aging is associated with increased leptin production that is independent from the amount of fat and/or the role of sex hormones. Conclusion: In conclusion, our data show that serum leptin concentrations in men and women gradually increase during aging, being higher in women than in men, but they are independent from BMI and other hormones. The inclusion of several hormones in our regression model showed that only testosterone in men, and estradiol and androstenedione in women were independent contributions to serum leptin levels, possibly accounting for part of the leptin sexual dimorphism in a south Indian population.

Association Between Body Mass Index and Mortality in an 80‐Year‐Old Population

To evaluate the association between body mass index (BMI) and all-cause mortality and cardiovascular disease (CVD) in an 80-year-old population. Cohort study. Community-based. Six hundred ninety-seven of 1,282 (54.4%) 80-year-old candidate individuals. The dates and causes of all deaths were followed up for 4 years. The relative hazard ratios (HRs) for all-cause mortality were lower in overweight subjects (BMI > or= 25.0) than in underweight (BMI<18.5) or normal-weight (BMI 18.5-24.9) subjects. Similarly, the HRs for mortality due to CVD in overweight subjects were 78% less (HR=0.22, 95% confidence interval (CI)=0.06-0.77) than those in underweight subjects, and those in normal weight subjects were 78% less (HR=0.22, 95% CI=0.08-0.60) than those in underweight subjects. Mortality due to CVD was 4.6 times (HR 4.64, 95% CI=1.68-12.80) as high in underweight subjects as in normal-weight subjects, and mortality due to cancers was 88% lower (HR=0.12, 95% CI=0.02-0.78) in the overweight group than in the underweight group. There were no differences in mortality due to pneumonia. Overweight status was associated with longevity and underweight with short life, due to lower and higher mortality, respectively, from CVD and cancer.