Showing papers in "Obesity Research in 2004"

Parent‐Child Feeding Strategies and Their Relationships to Child Eating and Weight Status

Abstract: Parental feeding styles may promote overeating or overweight in children. A comprehensive literature review was undertaken to summarize the associations between parental feeding styles and child eating and weight status. Twenty-two studies were identified. We systematically coded study attributes and outcomes and tested for patterns of association. Nineteen studies (86%) reported at least one significant association between parental feeding style and child outcome, although study methodology and results varied considerably. Studies measuring parental feeding restriction, as opposed to general feeding control or another feeding domain, were more likely to report positive associations with child eating and weight status. Certain associations differed by gender and by outcome measurement (e.g., rate of eating as opposed to total energy intake). Parental feeding restriction, but no other feeding domain, was associated with increased child eating and weight status. Longitudinal studies are needed to test underlying causal pathways, including bidirectional causal models, and to substantiate findings in the presence of other obesity risk factors.

Sarcopenic obesity predicts instrumental activities of daily living disability in the elderly.

Abstract: Objective: To determine the association of sarcopenic obesity with the onset of Instrumental Activities of Daily Living (IADL) disability in a cohort of 451 elderly men and women followed for up to 8 years. Research Methods and Procedures: Sarcopenic obesity was defined at study baseline as appendicular skeletal muscle mass divided by stature squared <7.26 kg/m2 in men and 5.45 kg/m2 in women and percentage body fat greater than the 60th percentile of the study sample (28% body fat in men and 40% in women). Incident disability was defined as a loss of two or more points from baseline score on the IADL. Subjects with disability at baseline (scores < 8) were excluded. Cox proportional hazards analysis was used to determine the association of baseline sarcopenic obesity with onset of IADL disability, controlling for potential confounders. Results: Subjects with sarcopenic obesity at baseline were two to three times more likely to report onset of IADL disability during follow-up than lean sarcopenic or nonsarcopenic obese subjects and those with normal body composition. The relative risk for incident disability in sarcopenic obese subjects was 2.63 (95% confidence interval, 1.19 to 5.85), adjusting for age, sex, physical activity level, length of follow-up, and prevalent morbidity. Discussion: This is the first study, to our knowledge, to indicate that sarcopenic obesity is independently associated with and precedes the onset of IADL disability in the community-dwelling elderly. The etiology of sarcopenic obesity is unknown but may include a combination of decreases in anabolic signals and obesity-associated increases in catabolic signals in old age.

Exercise-Induced Reduction in Obesity and Insulin Resistance in Women: a Randomized Controlled Trial

Abstract: Objectives: To determine the effects of equivalent diet- or exercise-induced weight loss and exercise without weight loss on subcutaneous fat, visceral fat, and insulin sensitivity in obese women. Research Methods and Procedures: Fifty-four premenopausal women with abdominal obesity [waist circumference 110.1 ± 5.8 cm (mean ± SD)] (BMI 31.3 ± 2.0 kg/m2) were randomly assigned to one of four groups: diet weight loss (n = 15), exercise weight loss (n = 17), exercise without weight loss (n = 12), and a weight-stable control group (n = 10). All groups underwent a 14-week intervention. Results: Body weight decreased by ∼6.5% within both weight loss groups and was unchanged in the exercise without weight loss and control groups. In comparison with controls, cardiorespiratory fitness improved within the exercise groups only (p 0.05). Visceral fat decreased within all treatment groups (p < 0.008), and these changes were not different from each other. In comparison with the control group, insulin sensitivity improved within the exercise weight loss group alone (p < 0.001). Discussion: Daily exercise without caloric restriction was associated with substantial reductions in total fat, abdominal fat, visceral fat, and insulin resistance in women. Exercise without weight loss was also associated with a substantial reduction in total and abdominal obesity.

Calcium and dairy acceleration of weight and fat loss during energy restriction in obese adults.

Abstract: Objective: Increasing 1, 25-dihydroxyvitamin D in response to low-calcium diets stimulates adipocyte Ca2+ influx and, as a consequence, stimulates lipogenesis, suppresses lipolysis, and increases lipid accumulation, whereas increasing dietary calcium inhibits these effects and markedly accelerates fat loss in mice subjected to caloric restriction Our objective was to determine the effects of increasing dietary calcium in the face of caloric restriction in humans Research Methods and Procedures: We performed a randomized, placebo-controlled trial in 32 obese adults Patients were maintained for 24 weeks on balanced deficit diets (500 kcal/d deficit) and randomized to a standard diet (400 to 500 mg of dietary calcium/d supplemented with placebo), a high-calcium diet (standard diet supplemented with 800 mg of calcium/d), or high-dairy diet (1200 to 1300 mg of dietary calcium/d supplemented with placebo) Results: Patients assigned to the standard diet lost 64 ± 25% of their body weight, which was increased by 26% (to 86 ± 11%) on the high-calcium diet and 70% (to 109 ± 16% of body weight) on the high-dairy diet (p < 001) Fat loss was similarly augmented by the high-calcium and high-dairy diets, by 38% and 64%, respectively (p < 001) Moreover, fat loss from the trunk region represented 190 ± 79% of total fat loss on the low-calcium diet, and this fraction was increased to 501 ± 64% and 662 ± 30% on the high-calcium and high-dairy diets, respectively (p < 0001) Discussion: Increasing dietary calcium significantly augmented weight and fat loss secondary to caloric restriction and increased the percentage of fat lost from the trunk region, whereas dairy products exerted a substantially greater effect

Sugar-added beverages and adolescent weight change.

Abstract: Objectives: The increase in consumption of sugar-added beverages over recent decades may be partly responsible for the obesity epidemic among U.S. adolescents. Our aim was to evaluate the relationship between BMI changes and intakes of sugar-added beverages, milk, fruit juices, and diet soda. Research Methods and Procedures: Our prospective cohort study included >10, 000 boys and girls participating in the U.S. Growing Up Today Study. The participants were 9 to 14 years old in 1996 and completed questionnaires in 1996, 1997, and 1998. We analyzed change in BMI (kilograms per meter squared) over two 1-year periods among children who completed annual food frequency questionnaires assessing typical past year intakes. We studied beverage intakes during the year corresponding to each BMI change, and in separate models, we studied 1-year changes in beverage intakes, adjusting for prior year intakes. Models included all beverages simultaneously; further models adjusted for total energy intake. Results: Consumption of sugar-added beverages was associated with small BMI gains during the corresponding year (boys: +0.03 kg/m2 per daily serving, p = 0.04; girls: +0.02 kg/m2, p = 0.096). In models not assuming a linear dose-response trend, girls who drank 1 serving/d of sugar-added beverages gained more weight (+0.068, p = 0.02) than girls drinking none, as did girls drinking 2 servings/d (+0.09, p = 0.06) or 3+ servings/d (+0.08, p = 0.06). Analyses of year-to-year change in beverage intakes provided generally similar findings; boys who increased consumption of sugar-added beverages from the prior year experienced weight gain (+0.04 kg/m2 per additional daily serving, p = 0.01). Children who increased intakes by 2 or more servings/d from the prior year gained weight (boys: +0.14, p = 0.01; girls +0.10, p = 0.046). Further adjusting our models for total energy intake substantially reduced the estimated effects, which were no longer significant. Discussion: Consumption of sugar-added beverages may contribute to weight gain among adolescents, probably due to their contribution to total energy intake, because adjustment for calories greatly attenuated the estimated associations.

Targeting parents exclusively in the treatment of childhood obesity: long-term results.

Abstract: Objective: To report the long-term change in children's overweight following a family-based health-centered approach where only parents were targeted compared with a control intervention where only children were targeted. Research Methods and Procedures: Fifty of the 60 children who participated in the original study were located 7 years later, and their weight and height were measured. At the point of the 7-year follow-up, the children were 14 to 19 years of age. Repeated measure ANOVA was used to test differences between the groups in percent overweight at different time-points. Results: Mean reduction in percent overweight was greater at all follow-up points in children of the parent-only group compared with those in the children-only group (p < 0.05). Seven years after the program terminated, mean reduction in children's overweight was 29% in the parent-only group vs. 20.2% in the children-only group (p < 0.05). Discussion: Over the long term, treatment of childhood obesity with the parents as the exclusive agents of change was superior to the conventional approach.

State-Level Estimates of Annual Medical Expenditures Attributable to Obesity*

Abstract: FINKELSTEIN, ERIC A., IAN C. FIEBELKORN, AND GUIJING WANG. State-level estimates of annual medical expenditures attributable to obesity. Obes Res. 2004;12:18 –24. Objective: To provide state-level estimates of total, Medicare, and Medicaid obesity-attributable medical expenditures. Research Methods and Procedures: We developed an econometric model that predicts medical expenditures. We used this model and state-representative data to quantify obesity-attributable medical expenditures. Results: Annual U.S. obesity-attributable medical expenditures are estimated at $75 billion in 2003 dollars, and approximately one-half of these expenditures are financed by Medicare and Medicaid. State-level estimates range from $87 million (Wyoming) to $7.7 billion (California). Obesity-attributable Medicare estimates range from $15 million (Wyoming) to $1.7 billion (California), and Medicaid estimates range from $23 million (Wyoming) to $3.5 billion (New York). Discussion: These estimates of obesity-attributable medical expenditures present the best available information concerning the economic impact of obesity at the state level. Policy makers should consider these estimates, along with other factors, in determining how best to allocate scarce public health resources. However, because they are associated with large SE, these estimates should not be used to make comparisons across states or among payers within states.

Resistin, Adiponectin, Ghrelin, Leptin, and Proinflammatory Cytokines: Relationships in Obesity

Abstract: Objective: To evaluate interactions among leptin, adiponectin, resistin, ghrelin, and proinflammatory cytokines [tumor necrosis factor receptors (TNFRs), interleukin-6 (IL-6)] in nonmorbid and morbid obesity. Research Methods and Procedures: We measured these hormones by immunoenzyme or radiometric assays in 117 nonmorbid and 57 morbidly obese patients, and in a subgroup of 34 morbidly obese patients before and 6 months after gastric bypass surgery. Insulin resistance by homeostasis model assessment, lipid profile, and anthropometrical measurements were also performed in all patients. Results: Average plasma lipids in morbidly obese patients were elevated. IL-6, leptin, adiponectin, and resistin were increased and ghrelin was decreased in morbidly obese compared with nonmorbidly obese subjects. After adjusting for age, gender, and BMI in nonmorbidly obese, adiponectin was positively associated with HDLc and gender and negatively with weight (β = −0.38, p < 0.001). Leptin and resistin correlated positively with soluble tumor necrosis factor receptor (sTNFR) 1 (β = 0.24, p = 0.01 and β = 0.28, p = 0.007). In the morbidly obese patients, resistin and ghrelin were positively associated with sTNFR2 (β = 0.39, p = 0.008 and β = 0.39, p = 0.01). In the surgically treated morbidly obese group, body weight decreased significantly and was best predicted by resistin concentrations before surgery (β = 0.45, p = 0.024). Plasma lipids, insulin resistance, leptin, sTNFR1, and IL-6 decreased and adiponectin and ghrelin increased significantly. Insulin resistance improved after weight loss and correlated with high adiponectin levels. Discussion: TNFα receptors were involved in the regulatory endocrine system of body adiposity independently of leptin and resistin axis in nonmorbidly obese patients. Our results suggest coordinated roles of adiponectin, resistin, and ghrelin in the modulation of the obesity proinflammatory environment and that resistin levels before surgery treatment are predictive of the extent of weight loss after bypass surgery.

Achieving weight and activity goals among diabetes prevention program lifestyle participants.

Abstract: Objective The Diabetes Prevention Program (DPP) showed that intensive lifestyle intervention reduced the risk of diabetes by 58%. This paper examines demographic, psychosocial, and behavioral factors related to achieving weight loss and physical activity goals in the DPP lifestyle participants. Research methods and procedures Lifestyle participants (n = 1079; mean age = 50.6, BMI = 33.9, 68% female, and 46% from minority groups) had goals of 7% weight loss and 150 min/wk of physical activity. Goal achievement was assessed at the end of the 16-session core curriculum (approximately week 24) and the final intervention visit (mean = 3.2 years) as a function of demographic, psychosocial, and behavioral variables. Results Forty-nine percent met the weight loss goal and 74% met the activity goal initially, while 37% and 67%, respectively, met these goals long-term. Men and those with lower initial BMI were more likely to meet activity but not weight loss goals. Hispanic, Asian, and Native Americans were more likely to meet the long-term activity goals, and whites were more likely to meet the initial weight loss goal. In multivariate analyses, meeting the long-term weight loss goal and both activity goals increased with age, while psychosocial and depression measures were unrelated to goal achievement. Dietary self-monitoring was positively related to meeting both weight loss and activity goals, and meeting the activity goal was positively related to meeting the weight loss goal. Participants who met initial goals were 1.5 to 3.0 times more likely to meet these goals long-term. Discussion Success at meeting the weight loss and activity goals increased with age. Initial success predicted long-term success. Self-monitoring and meeting activity goals were related to achieving and sustaining weight loss.

Increased portion size leads to increased energy intake in a restaurant meal.

Abstract: Objective: Eating frequently in restaurants is one of the behaviors associated with obesity. This study examined whether increasing the portion size of an entree affected energy intake at a restaurant meal. Research Methods and Procedures: In a cafeteria-style restaurant on different days, the size of a pasta entree was varied from a standard portion (248 g) to a large portion (377 g). The entree price was not changed. Intake of the entree was determined by covertly weighing each dish before and after the meal; intake of all other foods was determined by estimating the percent consumed. The 180 adult customers who purchased the entree also completed a survey in which they rated characteristics of the meal, including the appropriateness of the entree portion size and the amount that they ate compared with their usual meal. Results: Portion size had a significant effect on intake of the entree (p < 0.0001). Compared with customers who purchased the standard portion, those who purchased the larger portion increased their energy intake of the entree by 43% (719 kJ; 172 kcal) and of the entire meal by 25% (664 kJ; 159 kcal). There was no difference between the two groups of customers in ratings of the appropriateness of the portion size or of the amount that was eaten in relation to their usual meal. Discussion: In a restaurant setting, increasing the size of an entree results in increased energy intake. These results support the suggestion that large restaurant portions may be contributing to the obesity epidemic.

Efficacy of Lifestyle Modification for Long-Term Weight Control

Abstract: A comprehensive program of lifestyle modification induces loss of ∼10% of initial weight in 16 to 26 weeks, as revealed by a review of recent randomized controlled trials, including the Diabetes Prevention Program. Long-term weight control is facilitated by continued patient-therapist contact, whether provided in person or by telephone, mail, or e-mail. High levels of physical activity and the consumption of low-calorie, portion-controlled meals, including liquid meal replacements, can also help maintain weight loss. Additional studies are needed of the effects of macronutrient content (e.g., low-fat vs. low-carbohydrate diets) on long-term changes in weight and health. Research also is needed on effective methods of providing comprehensive weight loss control to the millions of Americans who need it.

Trends in the association between obesity and socioeconomic status in U.S. adults: 1971 to 2000.

Abstract: Objective: To study the secular trends in the disparity of obesity across socioeconomic status (SES) groups among U.S. adults. Research Methods and Procedures: We used national representative data collected in the National Health and Nutrition Examination Surveys conducted in 1971 to 1974, 1976 to 1980, 1988 to 1994, and 1999 to 2000 from 28, 543 adults 20 to 60 years old. Obesity was defined based on BMI calculated using measured weight and height. Trends in the relationship between obesity and education levels were analyzed controlling for age, gender, and ethnicity. Results: The disparity in obesity across SES (less than high school, high school, and college or above to indicate low, medium, and high SES, respectively) has decreased over the past 3 decades. In National Health and Nutrition Examination Surveys I (1971 to 1974), there was as much as a 50% relative difference in the obesity prevalence across the three groups, but by 1999 to 2000, it decreased to 14%. This trend was more pronounced in women. The trends of diminishing disparities in obesity were also revealed by our logistic and linear regression analyses. The odds ratio converged to 1 from the 1970s to 2000. In most sociodemographic groups, the relationship between BMI and SES (coefficients) has been weakened over time. Discussion: The association between SES and obesity has been weakened over the past 3 decades, when the prevalence of obesity increased dramatically. There are considerable variations in the changes in the associations across gender and ethnic groups. Our findings suggest that individual characteristics are not likely the main cause of the current obesity epidemic in the U.S., whereas social-environmental factors play an important role. Strategies for obesity prevention and management should target all SES groups from a societal perspective.

Childhood overweight and academic performance: national study of kindergartners and first-graders.

Abstract: DATAR, ASHLESHA, ROLAND STURM, AND JENNIFER L. MAGNABOSCO. Childhood overweight and academic performance: national study of kindergartners and first-graders. Obes Res. 2004;12:58‐68. Objective: To examine the association between children’s overweight status in kindergarten and their academic achievement in kindergarten and first grade. Research Methods and Procedures: The data analyzed consisted of 11,192 first time kindergartners from the Early Childhood Longitudinal Study, a nationally representative sample of kindergartners in the U.S. in 1998. Multivariate regression techniques were used to estimate the independent association of overweight status with children’s math and reading standardized test scores in kindergarten and grade 1. We controlled for socioeconomic status, parent-child interaction, birth weight, physical activity, and television watching. Results: Overweight children had significantly lower math and reading test scores compared with nonoverweight children in kindergarten. Both groups were gaining similarly on math and reading test scores, resulting in significantly lower test scores among overweight children at the end of grade 1. However, these differences, except for boys’ math scores at baseline (difference ! 1.22 points, p ! 0.001), became insignificant after including socioeconomic and behavioral variables, indicating that overweight is a marker but not a causal factor. Race/ethnicity and mother’s education were stronger predictors of test score gains or levels than overweight status. Discussion: Significant differences in test scores by overweight status at the beginning of kindergarten and the end of grade 1 can be explained by other individual characteristics, including parental education and the home environment. However, overweight is more easily observable by other students compared with socioeconomic characteristics, and its significant (unadjusted) association with worse academic performance can contribute to the stigma of overweight as early as the first years of elementary school.

Physical frailty and body composition in obese elderly men and women.

Abstract: Objective: To evaluate the prevalence of frailty and interrelationships among body composition, physical function, and quality of life in community-dwelling obese elderly (OE) persons. Research Methods and Procedures: Fifty-two OE, 52 nonobese frail, and 52 nonobese nonfrail subjects, matched for age and sex, were studied. Subjective and objective measures of functional status were evaluated by using the physical performance test, exercise stress test, lower extremity (LE) strength, gait speed, static and dynamic balance, functional status questionnaires, and health-related quality-of-life questionnaire (Medical Outcomes Short Form). Body composition was evaluated by using DXA, and muscle quality was evaluated by determining the ratio of LE strength to LE lean mass. Results: Among OE subjects, 96% met our standard criteria for mild to moderate frailty. Compared with the nonobese nonfrail group, the OE and nonobese frail groups had lower and similar scores in physical performance test, peak aerobic power, and functional status questionnaire, and exhibited similar impairments in strength, walking speed, balance, and health-related quality of life. Although absolute fat-free mass (FFM) was greater, the percentage body weight as FFM and muscle quality was lower in the OE group than in the other two groups. Discussion: Physical frailty, which predisposes to loss of independence, is common in community-living OE men and women. Physical frailty in OE subjects was associated with low percentage FFM, poor muscle quality, and decreased quality of life. These findings suggest that weight loss therapy may be particularly important in OE persons to improve physical function, in addition to improving the medical complications associated with obesity.

Sarcopenic obesity : the confluence of two epidemics

Abstract: The two greatest epidemiological trends of our times are the aging of the population and the obesity epidemic (1). Each of these trends has important effects on body composition, morbidity, and mortality. Aging causes a progressive loss of muscle mass and strength, independent of any disease process, called sarcopenia, from the Greek for “poverty of flesh” (2). Sarcopenia is an important cause of frailty, disability, and loss of independence in the elderly, and recent estimates suggest that it costs the United States over $18 billion per year, a sum on par with the economic consequences of osteoporosis (3–6). Weight loss is not necessary for the development of sarcopenia, but it accelerates it (4,7). In general, normal aging in the developed world means that most adults gain weight between the third and sixth decades, and then level off and lose a modest amount of weight through the ninth decade. Although decline in muscle mass can be documented as early as the fourth or fifth decade, especially in sedentary adults, overt sarcopenia is seen in 5–10% of adults in their sixties, rising to over 50% in healthy, ambulatory, community-dwelling adults over age eighty (8). Of course, the onset of acute or chronic illness accelerates muscle loss above and beyond the agerelated sarcopenia. Although the prevalence and time course of sarcopenia is reasonably well worked out, the impact of obesity on it is only now emerging as an important public health problem. Ironically, although weight gain causes an increase in lean mass as well as fat mass, obesity in the elderly acts synergistically with sarcopenia to maximize disability. The “fat frail” have the worst of both worlds as they age—increased weakness due to sarcopenia and a need to carry greater weight due to obesity (9). With the increase in obesity that has occurred in the past two decades, the prevalence of obese elderly is rising, and the impact of sarcopenic obesity is likely to be dramatic in the next decade. In this issue of the journal, Villareal et al. (10) provide one of the first systematic evaluations of sarcopenic obesity in contrast to both nonsarcopenic obese and lean adults of comparable age. The authors compared 52 obese elderly adults, 52 nonobese frail adults, and 52 nonobese, nonfrail persons, matched by age and sex. Despite a higher absolute amount of fat-free mass in the obese elders, these subjects had lower muscle quality (force per unit of cross-sectional muscle area) than the other two groups, and their functional performance, aerobic capacity, strength, balance, and walking speed were as severely reduced as the frail nonobese elders. Thus, these obese elderly adults had sarcopenia (low relative muscle mass, low muscle strength per muscle area) despite appearing the opposite of the stereotypical frail elderly adult. What is the biological connection between sarcopenia and obesity? Are we simply seeing the results of decades of little physical activity and positive energy balance? In fact, there is good reason to suspect that sarcopenia and obesity reinforce each other at several levels, both behavioral and biological (11). As people age, their physical activity level falls, reducing the most important trophic effect on muscle while at the same time predisposing people to positive energy balance and weight gain, most of which is fat. Beyond this, however, loss of muscle reduces the mass of available insulin-responsive target tissue, promoting insulin resistance, which, in turn, promotes the metabolic syndrome and obesity (12). Moreover, increasing fat mass promotes production of tumor necrosis factor, interleukin-6, and other adipokines that further promote insulin resistance as well as potentially a direct catabolic effect on muscle. Thus, a vicious cycle is created that leads to more gain in fat and more loss of muscle, until a threshold is crossed at which functional consequences such as disability and illnesses such as hypertension and diabetes occur. The results of the study by Villareal et al. suggest that sarcopenic obesity is a major public health problem in its own right. Until recently, the research communities studying each of these topics have had little contact with each other. Clearly, in the future more collaboration between those who study fat gain and those who study muscle loss Address correspondence to Ronenn Roubenoff, Molecular Medicine, Millennium Pharmaceuticals Cambridge, MA 02139. E-mail: roubenoff@mpi.com Copyright © 2004 NAASO

Energy-dense Snack Food Intake in Adolescence: Longitudinal Relationship to Weight and Fatness

Abstract: Objective: The longitudinal relationship between the consumption of energy-dense snack (EDS) foods and relative weight change during adolescence is uncertain. Using data from the Massachusetts Institute of Technology Growth and Development Study, the current analysis was undertaken to examine the longitudinal relationship of EDS food intake with relative weight status and percentage body fat and to examine how EDS food consumption is related to television viewing. Research Methods and Procedures: One hundred ninety-six nonobese premenarcheal girls 8 to 12 years old were enrolled between 1990 and 1993 and followed until 4 years after menarche. At each annual follow-up visit, data were collected on percentage body fat (%BF), BMI z score, and dietary intake. Categories of EDS foods considered were baked goods, ice cream, chips, sugar-sweetened soda, and candy. Results: At study entry, girls had a mean ± SD BMI z score of −0.27 ± 0.89, consumed 2.3 ± 1.7 servings of EDS foods per day, and consumed 15.7 ± 8.1% of daily calories from EDS foods. Linear mixed effects modeling indicated no relationship between BMI z score or %BF and total EDS food consumption. Soda was the only EDS food that was significantly related to BMI z score over the 10-year study period, but it was not related to %BF. In addition, a significant, positive relationship was observed between EDS food consumption and television viewing. Discussion: In this cohort of initially nonobese girls, overall EDS food consumption does not seem to influence weight status or fatness change over the adolescent period.

The human obesity gene map: the 2003 update.

Abstract: This is the tenth update of the human obesity gene map, incorporating published results up to the end of October 2003 and continuing the previous format. Evidence from single-gene mutation obesity cases, Mendelian disorders exhibiting obesity as a clinical feature, quantitative trait loci (QTLs) from human genome-wide scans and animal crossbreeding experiments, and association and linkage studies with candidate genes and other markers is reviewed. Transgenic and knockout murine models relevant to obesity are also incorporated (N = 55). As of October 2003, 41 Mendelian syndromes relevant to human obesity have been mapped to a genomic region, and causal genes or strong candidates have been identified for most of these syndromes. QTLs reported from animal models currently number 183. There are 208 human QTLs for obesity phenotypes from genome-wide scans and candidate regions in targeted studies. A total of 35 genomic regions harbor QTLs replicated among two to five studies. Attempts to relate DNA sequence variation in specific genes to obesity phenotypes continue to grow, with 272 studies reporting positive associations with 90 candidate genes. Fifteen such candidate genes are supported by at least five positive studies. The obesity gene map shows putative loci on all chromosomes except Y. Overall, more than 430 genes, markers, and chromosomal regions have been associated or linked with human obesity phenotypes. The electronic version of the map with links to useful sites can be found at http:obesitygene.pbrc.edu.

Long-term weight development in women: a 15-year follow-up of the effects of pregnancy.

Abstract: Objective: The aim of this study was to evaluate how well prepregnancy BMI, gestational weight gain, and postpartum weight retention predict retention of weight 15 years later among parous women Research Methods and Procedures: The Stockholm Pregnancy and Women's Nutrition (SPAWN) study is a long-term follow-up study of women who delivered children in 1984 to 1985 (n = 2342) The participants initially filled out questionnaires about their eating and exercise habits, social circumstances, etc before, during, and at 1 year after pregnancy Anthropometric data were also sampled Fifteen years later, these women were invited to take part in the follow-up study Anthropometric measurements were collected, and similar questions were asked Five hundred sixty-three women participated in the SPAWN 15-year follow-up study The sample was divided into groups to examine three presumably critical time periods: 1) overweight and normal weight before pregnancy; 2) low, intermediate, and high weight gainers during pregnancy; and 3) low, intermediate, and high weight retainers at 1 year after pregnancy Results: The overweight women did not gain more weight during pregnancy or retain more weight at 1 year follow-up High weight gainers during pregnancy retained more weight at the 1-year and the 15-year follow-ups High weight retainers had gained more during pregnancy and retained it at the 15-year follow-up Fifty-six percent of the high weight gainers during pregnancy ended up in the high weight retainers group Discussion: Women who are overweight before pregnancy do not have a higher risk of postpartum weight retention than normal weight women Thus, it is not necessarily the initially overweight woman who should be the target or focus of weight control programs during or after pregnancy Both high weight gainers and high weight retainers had higher BMI at the 15-year follow-up, although only 56% of the high weight gainers during pregnancy were also classified as high weight retainers at the 1-year follow-up Weight retention at the end of the postpartum year predicts future overweight 15 years later

Do psychosocial variables predict weight loss or mental health after obesity surgery? A systematic review.

Abstract: HERPERTZ, S., R. KIELMANN, A.M. WOLF, J. HEBEBRAND, AND W. SENF. Do psychosocial variables predict weight loss or mental health after obesity surgery? A systematic review. Obes Res. 2004;12:1554–1569. Objective: The objective of this study was to present a systematic review of psychological and psychosocial predictors of weight loss and mental health after bariatric surgery. This systematic review included all controlled and noncontrolled trials of the last 2 decades with either a retrospective or prospective design and a follow-up period of at least 1 year. Research Methods and Procedures: The relevant literature was identified by a search of computerized databases. All articles published in English and German between 1980 and 2002 were reviewed. Results: Using the above inclusion/exclusion criteria, 29 articles were identified focusing on psychosocial predictors of weight loss and mental health after obesity surgery. Discussion: Personality traits have no predictive value for the postoperative course of weight or mental state. Apart from serious psychiatric disorders including personality disorders, psychiatric comorbidity seems to be of more predictive value for mental and physical well-being as two essential aspects of quality of life than for weight loss postsurgery. However, depressive and anxiety symptoms as correlates of psychological stress with regard to obesity seem to be positive predictors of weight loss postsurgery. The severity of the symptoms or the disorder is more relevant for the outcome of obesity surgery than the specificity of the symptoms. It is also not solely the consumption of distinct “forbidden” foods, such as sweets or soft drinks, but rather a general hypercaloric eating behavior, either as an expression of the patient’s inadequate compliance or a dysregulation in energy balance, which is associated with a poor weight loss postsurgery.

A survey of genes differentially expressed in subcutaneous and visceral adipose tissue in men

Abstract: Adipose tissue located within the abdominal cavity has been suggested to be functionally and metabolically distinct from that of the subcutaneous compartment. These differences could play a role in obesity-related complications. The aim of this study was to compare gene expression profiles of subcutaneous and visceral adipose tissues of 10 nondiabetic, normolipidemic obese men. Affymetrix human U133A arrays (10 arrays for subcutaneous fat samples and 10 arrays for visceral fat samples) were used. Differential gene expression was confirmed by real-time polymerase chain reaction in a subset of genes. A total of 5894 transcripts were detected in both depots in all 10 subjects, and 409 transcripts representing 347 encoded genes were differentially expressed. Of these, 131 genes were expressed at higher levels in subcutaneous adipose tissue, and 216 were expressed more abundantly in visceral fat. Differentially expressed profiles included genes of the Wnt signaling pathway, as well as CEPBA and HOX genes. In addition, genes involved in lipolytic stimuli and cytokine secretion were differentially expressed. The identification of a consistent and rather uniform pattern of differentially expressed genes between the two fat depots using multiple array replicates (10 arrays per fat compartment) generated new perspectives for future research on regional differences in adipose tissue biology.

Moderate and severe obesity have large differences in health care costs.

Abstract: Objective: To analyze health care use and expenditures associated with varying degrees of obesity for a nationally representative sample of individuals 54 to 69 years old. Research Methods and Procedures: Data from the Health and Retirement Study, a nationwide biennial longitudinal survey of Americans in their 50s, were used to estimate multivariate regression models of the effect of weight class on health care use and costs. The main outcomes were total health care expenditures, the number of outpatient visits, the probability of any inpatient stay, and the number of inpatient days. Results: The results indicated that there were large differences in obesity-related health care costs by degree of obesity. Overall, a BMI of 35 to 40 was associated with twice the increase in health care expenditures above normal weight (about a 50% increase) than a BMI of 30 to 35 (about a 25% increase); a BMI of over 40 doubled health care costs (∼100% higher costs above those of normal weight). There was a difference by gender in how health care use and costs changed with obesity class. The primary effect of increasing weight class on health care use appeared to be through elevated use of outpatient health care services. Discussion: Obesity imposes an increasing burden on the health care system, and that burden grows disproportionately large for the most obese segment of the U.S. population. Because the prevalence of severe obesity is increasing much faster than that of moderate obesity, average estimates of obesity effects obscure real consequences for individuals, physician practices, hospitals, and health plans.

Effect of Internet Support on the Long‐Term Maintenance of Weight Loss

Abstract: Objective: To investigate the efficacy of an Internet weight maintenance program. Research Methods and Procedures: Two hundred fifty-five healthy overweight and obese adults (mean ± SD BMI, 31.8 ± 4.1 kg/m2) men (18%; mean ± SD age, 45.8 ± 8.9 yrs) participated in a 6-month behavioral weight control program conducted over interactive television. Treatment was followed by a 12-month weight maintenance program with three conditions: frequent in-person support (F-IPS), minimal in-person support (M-IPS) and internet support (IS). Main outcome measures included body weight, program adherence, and social influence components. Results: There were no significant differences among the groups in weight loss (mean ± SD) from baseline to 18 months (7.6 ± 7.3 kg vs. 5.5 ± 8.9 kg vs. 5.1 ± 6.5 kg, p = 0.23 for the IS, M-IPS, and F-IPS, respectively). Discussion: Participants assigned to an internet-based weight maintenance program sustained comparable weight loss over 18 months compared with individuals who continued to meet face-to-face. Therefore, the internet appears to be a viable medium for promoting long-term weight maintenance.

The role of overweight and obesity in calcium oxalate stone formation.

Abstract: Objective: The aim of the study was to assess the influence of overweight and obesity on the risk of calcium oxalate stone formation. Research Methods and Procedures: BMI, 24-hour urine, and serum parameters were evaluated in idiopathic calcium oxalate stone formers (363 men and 164 women) without medical or dietetic pretreatment. Results: Overweight and obesity were present in 59.2% of the men and in 43.9% of the women in the study population. Multiple linear regression analysis revealed a significant positive relationship between BMI and urinary uric acid, sodium, ammonium, and phosphate excretion and an inverse correlation between BMI and urinary pH in both men and women, whereas BMI was associated with urinary oxalate excretion only among women and with urinary calcium excretion only among men. Serum uric acid and creatinine concentrations were correlated with BMI in both genders. Because no association was established between BMI and urinary volume, magnesium, and citrate excretion, inhibitors of calcium oxalate stone formation, the risk of stone formation increased significantly with increasing BMI among both men and women with urolithiasis (p = 0.015). The risk of calcium oxalate stone formation, median number of stone episodes, and frequency of diet-related diseases were highest in overweight and obese men. Discussion: Overweight and obesity are strongly associated with an elevated risk of stone formation in both genders due to an increased urinary excretion of promoters but not inhibitors of calcium oxalate stone formation. Overweight and obese men are more prone to stone formation than overweight women.

A Novel Pathway to the Manifestations of Metabolic Syndrome

Abstract: Pathways leading from obesity to the manifestations of metabolic syndrome involve a number of metabolic risk factors, as well as adipokines, mediators of inflammatory response, thrombogenic and thrombolytic parameters, and vascular endothelial reactivity. Increased adipose tissue mass contributes to augmented secretion of proinflammatory adipokines, particularly tumor necrosis factor-alpha (TNF alpha), along with diminished secretion of the "protective" adiponectin. In our view, TNF alpha and adiponectin are antagonistic in stimulating nuclear transcription factor-kappa B (NF-kappa B) activation. Through this activation, TNF alpha induces oxidative stress, which exacerbates pathological processes leading to oxidized low-density lipoprotein and dyslipidemia, glucose intolerance, insulin resistance, hypertension, endothelial dysfunction, and atherogenesis. NF-kappa B activation further stimulates the formation of additional inflammatory cytokines, along with adhesion molecules which promote endothelial dysfunction. Elevated free fatty acid, glucose, and insulin levels enhance this NF-kappa B activation and further downstream modulate specific clinical manifestations of metabolic syndrome.

Body fat and fat-free mass and all-cause mortality.

Abstract: Objective: To investigate whether the association between BMI and all-cause mortality could be disentangled into opposite effects of body fat and fat-free mass (FFM). Research Methods and Procedures: All-cause mortality was studied in the Danish follow-up study “Diet, Cancer and Health” with 27, 178 men and 29, 875 women 50 to 64 years old recruited from 1993 to 1997. By the end of year 2001, the median follow-up was 5.8 years, and 1851 had died. Body composition was assessed by bioelectrical impedance. Cox regression models were used to estimate the relationships among body fat mass index (body fat mass divided by height squared), FFM index (FFM divided by height squared), and mortality. All analyses were adjusted for smoking habits. Results: Men and women showed similar associations. J-shaped associations were found between body fat mass index and mortality adjusted for FFM and smoking. The mortality rate ratios in the upper part of body fat mass were 1.12 per kg/m2 (95% confidence interval: 1.07, 1.18) in men and 1.06 per kg/m2 (95% confidence interval: 1.02, 1.10) in women. Reversed J-shaped associations were found between FFM index and mortality with a tendency to level off for high values of FFM. Discussion: Our findings suggest that BMI represents joint but opposite associations of body fat and FFM with mortality. Both high body fat and low FFM are independent predictors of all-cause mortality.

Evaluation of a quantitative magnetic resonance method for mouse whole body composition analysis.

Abstract: Objective: To evaluate applicability, precision, and accuracy of a new quantitative magnetic resonance (QMR) analysis for whole body composition of conscious live mice. Research Methods and Procedures: Repeated measures of body composition were made by QMR, DXA, and classic chemical analysis of carcass using live and dead mice with different body compositions. Caloric lean and dense diets were used to produce changes in body composition. In addition, different strains of mice representing widely diverse populations were analyzed. Results: Precision was found to be better for QMR than for DXA. The coefficient of variation for fat ranged from 0.34% to 0.71% compared with 3.06% to 12.60% for DXA. Changes in body composition in response to dietary manipulation were easily detected using QMR. An increase in fat mass of 0.6 gram after 1 week (p < 0.01) was demonstrated in the absence of hyperphagia or a change in mean body weight. Discussion: QMR and DXA detected similar fat content, but the improved precision afforded by QMR compared with DXA and chemical analysis allowed detection of a significant difference in body fat after 7 days of consuming a diet rich in fat even though average body weight did not significantly change. QMR provides a very precise, accurate, fast, and easy-to-use method for determining fat and lean tissue of mice without the need for anesthesia. Its ability to detect differences with great precision should be of value when characterizing phenotype and studying regulation of body composition brought about by pharmacological and dietary interventions in energy homeostasis.

The association between weight perception and BMI among high school students.

Abstract: Objective: To assess the association between weight perception and BMI among a large, diverse sample of adolescents. This study used both measured and self-reported height and weight to calculate BMI. Research Methods and Procedures: A convenience sample of students (n = 2032) in grades 9 through 12 completed a questionnaire assessing demographic characteristics, self-reported height and weight, and body weight perception. These students were then weighed and had their height measured using a standard protocol. Results: Using BMI calculated from measured height and weight, 1.5% of students were classified as underweight or at risk for underweight, 51.2% of students were normal weight, and 47.4% were overweight or at risk for overweight. Among this same sample of students, however, 34.8% perceived themselves as underweight, 42.9% perceived themselves as about the right weight, and 22.3% perceived themselves as overweight. Even when using BMI calculated from self-reported height and weight, >20% of students who were overweight or at risk for overweight perceived themselves as underweight. Discussion: Because perception of overweight is a key determinant of adolescent nutritional habits and weight management, many students who are overweight or at risk for overweight but who do not perceive themselves as such are unlikely to engage in weight control practices. Increasing awareness of medical definitions of overweight might improve accuracy of weight perceptions and lead to healthier eating and increased physical activity.

High local concentrations and effects on differentiation implicate interleukin-6 as a paracrine regulator.

Abstract: Objective: To examine the possibility that interleukin-6 (IL-6) can act as a paracrine regulator in adipose tissue by examining effects on adipogenic genes and measuring interstitial IL-6 concentrations in situ. Research Methods and Procedures: Circulating and interstitial IL-6 concentrations in abdominal and femoral adipose tissue were measured using the calibrated microdialysis technique in 20 healthy male subjects. The effects of adipose cell enlargement on gene expression and IL-6 secretion were examined, as well as the effect of IL-6 in vitro on gene expression of adiponectin and other markers of adipocyte differentiation. Results: The IL-6 concentration in the interstitial fluid was ∼100-fold higher than that in plasma, suggesting that IL-6 may be a paracrine regulator of adipose tissue. This was further supported by the finding that adding IL-6 in vitro at similar concentrations down-regulated the expression of adiponectin, aP2, and PPARγ-2 in cultured human adipose tissue. In addition, gene expression and release of IL-6, both in vivo and in vitro, correlated with adipose cell size. Discussion: These data suggest that IL-6 may be a paracrine regulator of adipose tissue. Furthermore, increased adipose tissue production of IL-6 after hypertrophic enlargement of the adipose cells may detrimentally affect systemic insulin action by inducing adipose tissue dysfunction with impaired differentiation of the pre-adipocytes and/or adipocytes and lower adiponectin.

The obesity pandemic: where have we been and where are we going?

Abstract: Obesity, a new pandemic, is associated with an increased risk of death, morbidity, and accelerated aging. The multiple therapeutic modalities used to promote weight loss are outlined with caution, especially for patients who are very young or old. Except for very rare single gene defects, the inheritance of obesity is complex and still poorly understood, despite active investigations. Recent advances that have shed light on the pathophysiology of obesity are the recognition that 1) excess fat is deposited in liver, muscle, and pancreatic islets; 2) fat tissue secretes a large number of active signaling molecules including leptin, adiponectin, and resistin, as well as free fatty acids; and 3) activated macrophages colonize the adipose tissue. Other candidates for key roles in the causes and consequences of obesity include 1) metabolic programming, where food acts as a developmental regulator; 2) the constellation of defects known as the "metabolic syndrome;" 3) cortisol overproduction in the adipose tissue; and especially, 4) insulin resistance. The possible etiologies of insulin resistance include cytokine excess, elevated free fatty acids, and hyperinsulinemia itself, as with transgenic overproduction of insulin in mice.

A Randomized Controlled Trial of a Commercial Internet Weight Loss Program

Abstract: WOMBLE, LESLIE G., THOMAS A. WADDEN, BRIAN G. MCGUCKIN, STEPHANIE L. SARGENT, REBECCA A. ROTHMAN, AND E. STEPHANIE KRAUTHAMEREWING. A randomized controlled trial of a commercial Internet weight loss program. Obes Res. 2004;12: 1011–1018. Objective: To assess, in a 1-year randomized controlled trial, the efficacy of eDiets.com (a commercial Internet weight loss program) in improving weight, cardiovascular health, and quality of life. Research Methods and Procedures: Participants were 47 women with a mean age of 43.7 10.2 (SD) years and a mean BMI of 33.5 3.1 kg/m 2 . They were randomly assigned to either: 1) eDiets.com, a commercial Internetbased program available to the public; or 2) a weight loss manual (i.e., LEARN Program for Weight Control 2000 ). At baseline, participants in both groups met briefly with a psychologist who instructed them to follow the components of their program as closely as possible. Additional brief visits were provided at weeks 8, 16, 26, and 52 to review their progress. Change in weight was the main outcome measure. Results: At week 16, participants in eDiets.com lost 0.9 3.2% of initial weight compared with 3.6 4.0% for women assigned to the weight loss manual. At week 52, losses increased to 1.1 4.0% and 4.0 5.1%, respectively. Results of a last-observation-carried-forward analysis found that women in the manual group lost significantly (p 0.05) more weight (at both times) than those treated by eDiets.com. (Results, however, of baseline-carried-forward and completers analyses did not reach statistical significance.) There were no significant differences between groups in changes in cardiovascular risk factors or quality of life. Discussion: This study provides consumers with important information about the probable benefits they can expect from participating in a popular Internet-based weight loss program.