Showing papers in "Obesity Reviews in 2004"

Obesity in children and young people: a crisis in public health.

Abstract: Ten per cent of the world’s school-aged children are estimated to be carrying excess body fat (Fig. 1), with an increased risk for developing chronic disease. Of these overweight children, a quarter are obese, with a significant likelihood of some having multiple risk factors for type 2 diabetes, heart disease and a variety of other co-morbidities before or during early adulthood. The prevalence of overweight is dramatically higher in economically developed regions, but is rising significantly in most parts of the world. In many countries the problem of childhood obesity is worsening at a dramatic rate. Surveys during the 1990s show that in Brazil and the USA, an additional 0.5% of the entire child population became overweight each year. In Canada, Australia and parts of Europe the rates were higher, with an additional 1% of all children becoming overweight each year. The burden upon the health services cannot yet be estimated. Although childhood obesity brings a number of additional problems in its train – hyperinsulinaemia, poor glucose tolerance and a raised risk of type 2 diabetes, hypertension, sleep apnoea, social exclusion and depression – the greatest health problems will be seen in the next generation of adults as the present childhood obesity epidemic passes through to adulthood. Greatly increased rates of heart disease, diabetes, certain cancers, gall bladder disease, osteoarthritis, endocrine disorders and other obesityrelated conditions will be found in young adult populations, and their need for medical treatment may last for their remaining life-times. The costs to the health services, the losses to society and the burdens carried by the individuals involved will be great. The present report has been written to focus attention on the issue and to urge policy-makers to consider taking action before it is too late. Specifically, the report:

Smoking cessation and weight gain.

Abstract: Cigarette smoking is the single most important preventable cause of death and illness. Smoking cessation is associated with substantial health benefits. Weight gain is cited as a primary reason for not trying to quit smoking. There is a great variability in the amount of weight gain but younger ages, lower socio-economic status and heavier smoking are predictors of higher weight gain. Weight change after smoking cessation appears to be influenced by underlying genetic factors. Besides, weight gain after smoking cessation is largely because of increased body fat and some studies suggest that it mostly occurs in the subcutaneous region of the body. The mechanism of weight gain includes increased energy intake, decreased resting metabolic rate, decreased physical activity and increased lipoprotein lipase activity. Although there is convincing evidence for the association between smoking cessation and weight gain, the molecular mechanisms underlying this relationship are not well understood. This review summarizes current information of the effects of nicotine on peptides involved in feeding behaviour. Smoking was shown to impair glucose tolerance and insulin sensitivity and cross-sectional studies have demonstrated that smokers are insulin-resistant and hyperinsulinaemic, as compared with non-smokers. Smoking cessation seems to improve insulin sensitivity in spite of the weight gain. Nicotine replacement - in particular nicotine gum - appears to be effective in delaying post-cessation weight gain. In a group of women who failed to quit smoking because of weight gain, a dietary intervention (intermittent very-low-calorie diet) plus nicotine gum showed to both increase success rate in terms of smoking cessation and prevent weight gain. On the other hand, body weight gain at the end of treatment was significantly lower in the patients receiving bupropion or bupropion plus nicotine patch, compared with placebo. Studies with new drugs available for the treatment of obesity - sibutramine and orlistat - are warranted.

Direct effects of sex steroid hormones on adipose tissues and obesity

Abstract: Summary Sex steroid hormones are involved in the metabolism, accumulation and distribution of adipose tissues. It is now known that oestrogen receptor, progesterone receptor and androgen receptor exist in adipose tissues, so their actions could be direct. Sex steroid hormones carry out their function in adipose tissues by both genomic and nongenomic mechanisms. In the genomic mechanism, the sex steroid hormone binds to its receptor and the steroid–receptor complex regulates the transcription of given genes. Leptin and lipoprotein lipase are two key proteins in adipose tissues that are regulated by transcriptional control with sex steroid hormones. In the nongenomic mechanism, the sex steroid hormone binds to its receptor in the plasma membrane, and second messengers are formed. This involves both the cAMP cascade and the phosphoinositide cascade. Activation of the cAMP cascade by sex steroid hormones would activate hormone-sensitive lipase leading to lipolysis in adipose tissues. In the phosphoinositide cascade, diacylglycerol and inositol 1,4,5-trisphosphate are formed as second messengers ultimately causing the activation of protein kinase C. Their activation appears to be involved in the control of preadipocyte proliferation and differentiation. In the presence of sex steroid hormones, a normal distribution of body fat exists, but with a decrease in sex steroid hormones, as occurs with ageing or gonadectomy, there is a tendency to increase central obesity, a major risk for cardiovascular disease, type 2 diabetes and certain cancers. Because sex steroid hormones regulate the amount and distribution of adipose tissues, they or adipose tissue-specific selective receptor modulators might be used to ameliorate obesity. In fact, hormone replacement therapy in postmenopausal women and testosterone replacement therapy in older men appear to reduce the degree of central obesity. However, these therapies have numerous side effects limiting their use, and selective receptor modulators of sex steroid hormones are needed that are more specific for adipose tissues with fewer side effects.

Obesity, adipocytokines, and insulin resistance in breast cancer.

Abstract: The adipocytokines are biologically active polypeptides that are produced either exclusively or substantially by the adipocytes, and act by endocrine, paracrine, and autocrine mechanisms Most have been associated with obesity, hyperinsulinaemia, type 2 diabetes, and chronic vascular disease; in addition, six adipocytokines--vascular endothelial growth factor, hepatocyte growth factor, leptin, tumour necrosis factor-alpha, heparin-binding epidermal growth factor-like growth factor, and interleukin-6--promote angiogenesis while one, adiponectin, is inhibitory Obesity and insulin resistance have both been identified as risk factors for breast cancer and are associated with late-stage disease and poor prognosis Angiogenesis is essential for breast cancer development and progression, and so it is plausible that obesity-related increases in adipocytokine production and a reduction in adiponectin may adversely affect breast cancer outcome by their angiogenesis-related activities There is also experimental evidence that some adipocytokines can act directly on breast cancer cells to stimulate their proliferation and invasive capacity Thus, adipocytokines may provide a biological mechanism by which obesity and insulin resistance are causally associated with breast cancer risk and poor prognosis Both experimental and clinical studies are needed to develop this concept, and particularly in oestrogen-independent breast cancers where preventive and therapeutic options are limited

Hepatic steatosis in obese patients: clinical aspects and prognostic significance

Abstract: Summary Non-alcoholic fatty liver disease is a new clinicopathological condition of emerging importance, now recognized as the most common cause of abnormal liver tests. It is characterized by a wide spectrum of liver damage: simple steatosis may progress to advanced fibrosis and to cryptogenic cirrhosis through steatohepatitis, and ultimately to hepatocellular carcinoma. Obesity is the most significant single risk factor for the development of fatty liver, both in children and in adults; obesity is also predictive of the presence of fibrosis, potentially progressing to advanced liver disease. From a pathogenic point of view, insulin resistance plays a central role in the accumulation of triglycerides within the hepatocytes and in the initiation of the inflammatory cascade. Chronic hepatocellular injury, necroinflammation, stellate cell activation, progressive fibrosis and ultimately, cirrhosis may be initiated by peroxidation of hepatic lipids and injury-related cytokine release. In the last few years, several pilot studies have shown that treatment with insulin-sensitizing agents, anti-oxidants or cytoprotective drugs may be useful, but there is no evidence-based support from randomized clinical trials. Modifications in lifestyle (e.g. diet and exercise) to reduce obesity remain the mainstay of prevention and treatment of a disease, which puts a large number of individuals at risk of advanced liver disease in the near future.

Effects of obesity on women's reproduction and complications during pregnancy.

Abstract: Obesity is increasing rapidly among women all over the world, and more women in fertile ages become overweight and obese. Among all other problems, women who are obese have higher rates of amenorrhoea and infertility. Obese women have a higher risk of complications during pregnancy such as hypertensive diagnoses and gestational diabetes, and delivery complications such as higher rates of caesarean sections and prolonged time of delivery. The aim of this article is to review the consequences of being obese during the reproductive life of a woman.

Childhood sexual abuse and obesity.

Abstract: The causes of the current obesity epidemic are multifactorial and include genetic, environmental, and individual factors. One potential risk factor may be the experience of childhood sexual abuse. Childhood sexual abuse is remarkably common and is thought to affect up to one-third of women and one-eighth of men. A history of childhood sexual abuse is associated with numerous psychological sequelae including depression, anxiety, substance abuse, somatization, and eating disorders. Relatively few studies have examined the relationship between childhood sexual abuse and adult obesity. These studies suggest at least a modest relationship between the two. Potential explanations for the relationship have focused on the role of disordered eating, particularly binge eating, as well as the possible "adaptive function" of obesity in childhood sexual abuse survivors. Nevertheless, additional research on the relationship between childhood sexual abuse and obesity is clearly needed, not only to address the outstanding empirical issues but also to guide clinical care.

Effects of weight loss in overweight/obese individuals and long-term lipid outcomes: a systematic review

Abstract: This paper aims to review the evidence for long-term effectiveness of weight loss on cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglycerides in overweight/obese people. Current evidence is mostly based on short-term studies. A systematic review of long-term lipid outcomes of weight loss in studies published between 1966 and 2001, was conducted. Inclusion criteria included all cohort studies and trials carried out on participants with body mass index of greater than or equal to 28 kg m(-2). Studies had at least two weight change measurements and follow-up of more than 2 years. Thirteen long-term studies with a follow-up of more than 2 years were included. Cholesterol has a significant positive linear relationship with weight change (r = 0.89) where change in weight explains about 80% of the cholesterol difference variation (Adj R2 = 0.80). For every 10 kg weight loss a drop of 0.23 mmol L(-1) in cholesterol may be expected for a person suffering from obesity or are grossly overweight. Weight loss has long-term beneficial effects especially on LDL and cholesterol. Weight loss in obese patients should be encouraged and sustained.

Obesity as a disease: no lightweight matter.

Abstract: The epidemic rise in obesity has fuelled the current debate over its classification as a disease. Contrary to just being a medical condition or risk factor for other diseases, obesity is a complex disease of multifaceted aetiology, with its own disabling capacities, pathophysiologies and comorbidities. It meets the medical definition of disease in that it is a physiological dysfunction of the human organism with environmental, genetic and endocrinological aetiologies. It is a response to environmental stimuli, genetic predisposition and abnormalities, and has a characteristic set of signs and symptoms with consistent anatomical alterations. Excess adipose tissue increases the work of the heart and leads to anatomical changes in this organ. It alters pulmonary, endocrine and immunological functions, all with adverse effects on health. Some of the complications of obesity include cardiovascular disease, non-insulin-dependent diabetes mellitus, obstructive pulmonary disease, arthritis and cancer. Given the excess mortality, substantial morbidity and the economic toll of obesity, this is a disease that warrants serious attention by the medical community. Obesity's status and acceptance as a disease is pivotal in determining its treatment, reimbursement for treatment and the development of widespread interventions.

Fatty acid composition of fats is an early determinant of childhood obesity: a short review and an opinion

Abstract: The importance of dietary fat in human obesity remains a controversial issue as the prevalence of overweight and obesity has increased despite no dramatic change in the amount of ingested fats over the past few decades. However, qualitative changes (i.e. the fatty acid composition of fats) have been largely disregarded. In this review, we summarize experimental evidence which supports polyunsaturated fatty acids of the omega6 series as being potent promoters of both adipogenesis in vitro and adipose tissue development in vivo during the gestation/lactation period. This conclusion is also supported by epidemiological data from infant studies as well as by the assessment of the fatty acid composition of mature breast milk and formula milk. It is proposed that unnoticed changes in fatty acid composition of ingested fats over the last decades have been important determinants in the increasing prevalence of childhood overweight and obesity.

Psychiatric medication-induced obesity: a review.

Abstract: A majority of psychiatric medications are known to generate weight gain and ultimately obesity in some patients. There is much speculation about the prevalence of weight gain and the degree of weight gain during acute and longitudinal treatment with these agents. There is newer literature looking at the aetiology of this weight gain and the potential treatments being used to alleviate this side-effect. We found solid evidence that weight gain is often associated with the mood stabilizers, and antipsychotics and antidepressants. Only few weight neutral or weight loss producing psychotropics are available, and weight gain, outside of an immediate side-effect, may generate secondary side-effects and medical comorbidity. Weight gain may cause hypertension, diabetes, osteoarthritis, sedentary lifestyle, coronary artery disease, etc. Given the likelihood of inducing weight gain with psychotropic medications and the longitudinal impact on physical health, a thorough literature review is warranted to determine the epidemiology, aetiology and treatment options of psychotropic-induced weight gain.

Caloric restriction, body fat and ageing in experimental models

Abstract: Caloric restriction in animal models delays many age-related pathological conditions. Ageing rats have characteristically increased body weight, fat mass and a specific body fat distribution. This report will focus on the potential cause-effect relationship between increased fat mass and accelerated ageing. In humans, increased fat mass (obesity), and in particular increases in abdominal obesity as a result of deposition of visceral fat, are associated with the metabolic syndrome of ageing. This syndrome is associated with hyperinsulinaemia, dyslipidaemia, type 2 diabetes mellitus, atherosclerosis, hypercoagulability and hypertension. Fat tissue, however, plays a major role by secreting multiple metabolically active factors, which are potentially responsible for the development of insulin resistance. This article will review various experimental models (in animals) used to prevent insulin resistance of ageing by decreasing fat mass, and in particular, decreasing visceral fat. We suggest that this decrease in fat mass and its beneficial repercussions observed in ageing animal models may apply also to human ageing and its related pathology.

Discrepancies between classification systems of childhood obesity.

Abstract: Despite growing concern about weight-related problems among children, no universally accepted classification system for childhood obesity exists. There is a number of proposed international body mass index (BMI)-based systems in use and national variants also exist in many countries. The absence of a universally accepted standard and confusion concerning which classification system to use on national levels complicate monitoring of the development of the obesity epidemic, stratification for selective interventions in public health, screening in clinical practice and comparisons between studies. Some proposed international classification systems have not only been recommended for global monitoring and comparisons between studies, but also for clinical and national epidemiological use in some countries. Possible discrepancies may thereby lead to inefficiencies in health care delivery and prevention programmes. The problems associated with misclassification of individuals at risk may lead to overconsumption of health care resources by lower-risk individuals and underconsumption by higher-risk individuals, which is costly both in terms of foregone health improvements and in terms of wasteful monetary usage. The aim of this paper was to review the specific problems associated with BMI as a measure of adiposity in childhood, the most commonly used classification systems for childhood obesity based on BMI, and how their performance can be evaluated.

A systematic review of the clinical effectiveness of orlistat used for the management of obesity

Abstract: The aim of this paper is to assess the clinical effectiveness of orlistat used for the management of obesity. Nineteen electronic databases were searched for randomized controlled trials evaluating the effectiveness of orlistat for weight loss or maintenance of weight loss in overweight or obese patients. Each included trial was assessed for methodological quality. Statistical pooling was performed when trials were considered to be sufficiently similar. Twenty-three trials were eligible for inclusion. Placebo-controlled trials recruiting patients with uncomplicated obesity reported statistically significant differences in favour of orlistat for weight loss and changes in obesity-related risk factors at all time points. Trials in obese patients with defined risk factors at baseline showed similar results, however, smaller effect sizes were observed in patients with type 2 diabetes. The effectiveness of orlistat relative to other anti-obesity drugs is currently unclear. When orlistat was added to simvastatin, this proved to be more effective for weight loss than either drug used individually. Orlistat use is associated with a higher incidence of gastrointestinal adverse events compared with placebo. In conclusion, orlistat is more effective than placebo in promoting weight loss, maintenance of weight loss, and improving cardiovascular risk factor profiles. Baseline parameters of patients seen in clinical practice should be taken into account when considering treatment.

Prevalence of obesity in Spain.

Abstract: Obesity is a health problem affecting an important proportion of the Spanish population. Overweight is more common among men than women whereas, obesity is more prevalent among women. The most recent data (2001) from self-reported weight and height measurements of a Spanish representative sample (21120 subjects) revealed that the overall obesity prevalence in Spain was about 13%, while direct anthropometric data obtained from pooled surveys concerning eight Spanish regions (9885 subjects), which were carried out between 1990-2000 the obesity prevalence averaged 14.5%.

Psychiatric medication induced obesity: an aetiologic review.

Abstract: A majority of psychiatric medications are known to generate weight gain and ultimately obesity in some patients. There is much speculation about the prevalence of weight gain and the degree of weight gain during acute and longitudinal treatment, but consensus shows that weight gain is prominent. The present review looked at the aetiology and cause of weight gain associated with psychotropic use and presents hypotheses as to why patients gain weight on antipsychotics, mood stabilizers and antidepressants. It is found that most psychotropic medications induce some weight gain, and clinicians are encouraged to utilize active interventions to alleviate the weight gain in order to prevent more serious obesity related comorbidities.

Current status of bariatric surgery in the treatment of type 2 diabetes

Abstract: Bariatric surgery (from the Greek words baros meaning 'weight' and iatrikos 'the art of healing') is a rapidly evolving branch of surgical science. The aim is to induce major weight loss in those whose obesity places them at high risk of serious health problems. In an attempt to balance the risks of surgery against the benefits of weight loss, bariatric operations are currently performed only in the morbidly obese, or those with a body mass index (BMI) > 35 kgm(-2) who already have developed comorbidity such as type 2 diabetes. Although weight loss is beneficial for obese patients with diabetes, current medical treatment for obesity is difficult. In contrast, observational studies show a major impact of bariatric surgery on diabetes, raising the question whether this approach should be used more widely to treat diabetes in obese patients? If bariatric surgery were shown to be the best way to treat diabetes in obese subjects the implications for health services would be wide-ranging. Bariatric surgery leads to withdrawal of diabetic treatment in about 60% or more of patients, and reductions of therapy for many others. Although data on bariatric surgery in subjects with diabetes are provocative, most studies have been uncontrolled or flawed in other ways. Most importantly, bariatric surgery has not yet been compared against standard medical treatment for diabetes in randomized controlled trials with diabetes-specific endpoints in all relevant patient groups. Potential indications for bariatric surgery are discussed, and the unanswered questions that need to be addressed by clinical trials are summarized. Although small numbers of patients may be interested in bariatric surgery for type 2 diabetes, current data are insufficient to endorse its wide scale use for this indication. Until essential studies are undertaken the role and economics of bariatric surgery in the diabetic clinic will remain uncertain.

Psychiatric medication-induced obesity: treatment options.

Abstract: A majority of psychiatric medications are known to generate weight gain and ultimately obesity in some patients. The authors undertook a comprehensive literature review in order to provide a better understanding of novel treatment options in regards to alleviating weight gained by use of antidepressants, antipsychotics, and mood stabilizers. There are no agents for management of this weight gain approved by the Food and Drug Administration (FDA), and existing studies on options are mainly uncontrolled, small-scale projects with limited power to produce coherent conclusions. There is a clear need for larger studies on existing options, and future psychotropics without these side-effects are currently in the pipeline.

Comment: the global epidemic of childhood obesity: is there a role for the paediatrician?

Abstract: Is there a role for the paediatrician in the global epidemic of childhood obesity? The answer should be obvious. When parents and the society are concerned about child health, they still turn to health professionals caring for children and adolescents, such as paediatricians, family practitioners , general practitioners or nurses. The report of the International Obesity TaskForce to the World Health Organization in this issue of Obesity Reviews (1) estimates that about 10% of young people aged 5–17 years are overweight , among which 2–3% are obese, corresponding for the year 2000 to 155 million overweight children including 30–45 million obese children worldwide. This report also describes how the burden of paediatric obesity is unequally distributed between regions of the world, and even between populations within countries. While paediatric obesity is still a relatively marginal problem in Sub-Saharan Africa and in large parts of the Asia-Pacific region, it is rapidly becoming the most frequent chronic paediatric condition in many countries of the Americas, Europe and the Near/ Middle East. Therefore, at least in these regions, the primary health care providers for children can no longer ignore such a frequent problem. Most paediatricians actually are very concerned about obesity in their young patients, and feel that they have to do something about it, anything! But most also feel unprepared, ill-equipped, and frankly ineffective to address the problem (2). One of the reasons for the paediatrician's awkwardness with the obesity epidemic is that the approach of obese children and adolescents has almost only focused on weight loss. Pediatricians often do not have the training and the skills for weight management using behaviour modification (2), and such programmes are difficult to implement in the office setting under the classic acute paediatric care model. Most approaches involve a team, including a dietitian, a psychologist, or/and a physical activity specialist, resources that are usually not available in the paediatric office or even in referral centres. Therefore primary care providers are faced with pressing requests to which they are unable to respond alone. Even if they could, in many countries where medicine is not socialized, these efforts are not financially compensated (3), discouraging involvement outside the traditional boundaries of the paediatric practice. Clearly, considering the size of the obesity epidemic, not all obese children will be able to be treated by a specialized team, and creative solutions need to be generated for weight management in the …

Role of candidate genes in the responses to long-term overfeeding: review of findings.

Abstract: Summary An overfeeding experiment conducted with 12 pairs of young male identical twins revealed that genetic factors were likely to play an important role in the response to caloric affluence. Significant intrapair resemblance was observed for the overfeeding-induced changes in body weight, fat mass, abdominal fat, fasting insulin, fasting cholesterol and triglycerides. In an attempt to define the molecular basis of these genotype–energy balance interaction effects, a panel of candidate genes has been investigated. Among the most significant findings, an adipsin polymorphism was associated with increases in body weight, total fat mass and subcutaneous fat in response to overfeeding. In addition, the beta2 adrenergic receptor gene Gln27Glu polymorphism showed a strong association with the gains in body weight and subcutaneous fat. Only a few markers were related to abdominal fat changes and, among them, the adipsin Hinc II polymorphism was associated with both computed tomography (CT)-measured abdominal visceral and total fat. The changes in insulin parameters brought about by long-term overfeeding were influenced most consistently by leptin receptor (LEPR) Gln223Arg and insulin-like growth factor-II Apa I polymorphisms. The LEPR Gln223Arg variant was also associated with the changes in plasma total triglycerides and high-density lipoprotein cholesterol concentrations. Further research with larger sample sizes should make it possible to identify the specific contributions of DNA sequence variations at multiple candidate gene loci in the complex response to chronic positive energy balance.

Aetiology of obesity: a striving after wind?

Abstract: Summary The current global epidemic of obesity is fuelled by a constant, unidirectional adverse effect on energy balance that exceeds the adaptive capacity of the system. The individual response to this environmental pressure is under the control of a variety of genes, which not only interacts with environmental factors but also with one another. Since the discovery that adipocytes may produce and secrete hormones, the adipose tissue has taken on increasing importance in the regulation of energy balance. Indeed, the pathogenesis of obesity, once regarded as so obvious and simple, is becoming one of the most complex in medical practice. From a clinical perspective, obesity is associated with a remarkably broad spectrum of health complications and, over the years, obesity-related mortality has consistently increased. From a theoretical viewpoint, the growing complexity of factors affecting the liability to obesity, the inconsistency of scientific results, the lack of consensus among scientists, and so forth, obstruct our efforts to unravel the aetiology of obesity. Is the field of obesity research merely a striving after wind, and nothing more?

Adipose tissue: new therapeutic targets from molecular and genetic studies – IASO Stock Conference 2003 report

Abstract: This review highlights the presentations and discussions held during the 2003 Stock Conference in Lisbon focussed on the identification of new therapeutic targets for the treatment of obesity and identified through molecular and genetic studies. Transcription factors and their cofactors, signalling pathways and new insights provided by cellular and genetic studies were discussed as potential new avenues to modulate adipocyte formation and function

The cause of obesity: are we barking up the wrong tree?

Abstract: Obesity may be more complex than most other societal problems we have faced so far. Viewed from an energy balance viewpoint, obesity can be thought of as a failure of our biological regulatory system for balancing the energy we take in from the food we eat and drinks with the energy we expend as metabolism and to perform physical activity. While some have approached obesity as resulting primarily from a ‘defect’ in the biological system itself, the problem may also be viewed as an evolving environment that is overwhelming the biological regulation of energy balance and leads to obesity. There are strong arguments for the latter point of view. First, the increase in the prevalence of obesity globally is too rapid to be associated with major genetic changes. Second, while more than 400 genes have been identified to play a role in body weight regulation, only a handful of humans worldwide have been shown to have a true ‘genetic obesity’. In the face of unidirectional environmental pressures to eat more and move less, our biological systems cannot maintain energy balance. Historically, resisting weight gain has not had great evolutional value. Put simply, for most of our history we have had no need to defend against positive energy balance. In this way, it is not our physiology that is abnormal, it is our environment. There is increasing recognition that obesity is not just a personal responsibility, but a societal issue and that dealing with it will not be simple. The factors in our environment that contribute to positive energy balance represent aspirations to which our ancestor aspired, such as having a constant supply of food and not having to work hard to secure food, shelter and safety. Obesity may be a by-product of our success as a society and it is unlikely we are willing to give up our food security and our labour-saving devices. Our challenge is not to go backwards in time to an environment that was conducive to a healthy body weight, but to learn how to modify our current environment in ways to achieve both healthy weights for our population and a high quality of life.

Evaluating commercial weight loss programmes: an evolution in outcomes research.

Abstract: Summary The increasing prevalence of obesity has been mirrored by a parallel increase in the number of commercial weight loss programmes. Research evaluating these programmes is meagre, however, compared to the numbers treated. Reluctance of commercial weight loss programmes to meaningfully evaluate their weight loss efficacy may arise from fear that competitors will use the results against them. Evaluation of commercial weight loss programmes usually progresses from testimonials, often by famous people who were successful, to uncontrolled studies of past participants evaluated either by the programme itself or by an outside entity. The gold standard, however, is a scientifically rigorous, controlled study of the programme conducted by an independent entity. Such a study, published in a peer-reviewed journal, can gain credibility for a programme, as it did with Slim Fast, if the results are positive, or herald the end of the programme, as it was with Simeons human chorionic gonadotropin injection clinics. This review of the evolution of the evaluation process of commercial weight loss programmes leads us to conclude that consumers are likely to demand greater scientific rigour in the future, a change that will favour informed choice and discourage the practice of unrealistic advertising that raises false hopes.

The Quebec Overfeeding Study: a catalyst for new hypothesis generation.

Abstract: Submitted by admin on Mon, 09/08/2014 4:02pm Title The Quebec Overfeeding Study: a catalyst for new hypothesis generation. Publication Type Journal Article Year of Publication 2004 Authors Redden, DT, Allison, DB Journal Obes Rev Volume 5 Issue 1 Pagination 1-2 Date Published 2004 Feb ISSN 1467-7881

Substrate metabolism, nutrient balance and obesity development in children and adolescents: a target for intervention?

Abstract: Obesity results from the organism's inability to maintain energy balance over a long term. Childhood obesity and its related factors and pathological consequences tend to persist into adulthood. A cluster of factors, including high energy density in the diet (high fat intake), low energy expenditure, and disturbed substrate oxidation, favour the increase in fat mass. Oxidation of three major macronutrients and their roles in the regulation of energy balance, particularly in children and adolescents, are discussed. Total glucose oxidation is not different between obese and lean children; exogenous glucose utilization is higher whereas endogenous glucose utilization is lower in obese compared with lean children. Carbohydrate composition of the diet determines carbohydrate oxidation regardless of fat content of the diet. Both exogenous and endogenous fat oxidation are higher in obese than in lean subjects. The influence of high fat intake on accumulation of fat mass is operative rather over a long term. Several future directions are addressed, such that a combination of increased physical activity and modification in diet composition, in terms of energy density and glycemic index, is recommended for children and adolescents.

Increasing the impact of European obesity research in preparation for the European research area: a report on the 2003 European Commission Obesity Workshop.

Abstract: Summary Leading obesity researchers from across Europe assembled in Aberdeen, Scotland, in January 2003 to consider how to increase the impact of European obesity research. The workshop was funded by the European Commission and hosted by the Rowett Research Institute, Aberdeen. The delegates identified the need to (i) develop a portfolio of studies that integrate genetics and mechanisms through parallel study of humans and animal models and (ii) establish major intervention studies in weight management and early life nutrition. It was recommended that these goals would be best achieved under the umbrella of a virtual European Obesity Research Institute, or Network of Excellence in Obesity Research under Framework Programme 6, that would facilitate harmonization of methodology, manage centralized standardized resources, coordinate training initiatives, workshops and working groups, and increase focus.

Prevalence of obesity in Uruguay.

Abstract: Uruguay is a small South American country with a mild climate. The population is a little more than 3 million, predominantly Caucasian, mostly descendants of Spanish, Italian and central European immigrants. There are very few inhabitants of Indian and African–American descent. There is a predominant middle class, and 40% of the inhabitants live in the capital, Montevideo. About 50% of the population receive medical assistance at the public hospitals, 40% from the insurance organizations, and 10% at private physicians. As in most parts of the civilized world, the problems of excess weight are also very important in Uruguay. This paper presents recent epidemiological investigations made at the turn of the century, and tries to compare them with investigations made 10 years earlier.

Are we getting fat from the foods we do not eat

Abstract: Obesity is increasing at an alarming rate in most countries, not least in the UK and USA. It is now well recognized that this development dramatically increases the incidence of type 2 diabetes, and to some extent cardiovascular disease and cancers, and reduces life expectancy by several years (1). The general decrease in the level of physical activity is well accepted to play an important role, but societal changes such as the increase in physically passive occupations centred around computers and leisure activities dominated by television and videos cannot alone account for the rapid increase in obesity. It is time to refocus our attention on the dietary factors that may underpin weight gain. Despite reported decreases in dietary fat, the proportion of obese individuals in the population continues to rise (2). This may be resulting from under-reporting of fat consumption, or decreases in fat alone may be insufficient to curb the rise in obesity. There is good experimental evidence that a reduction in the proportion of energy from dietary fat, for example, from 40% to 30%, automatically leads to a reduction in energy intake and produces a slight weight loss of approximately 3–5 kg, at least in the short term (3). Likewise a substantial reduction in the consumption of soft drinks and yogurts with added sugars may produce another 2 kg weight loss (4). Such losses are small in the clinical treatment of people with an excess body weight of 20–30 kg, but in a public health context, these small losses may offset the upward year-on-year drift in body weight. But we need to do more. Recent research suggests we have perhaps concentrated too much on the foods we should reduce and forgotten to encourage people to eat more of the obesity-protective, high-satiety foods. Consider for a moment all the foods that we have dropped in exchange for fish and chips, pizza, burgers, white bread and sugary drinks? In the latter half of the 20th century the rate of obesity has increased 5–10fold and at the same time the consumption of vegetables in the UK has fallen by 28%, bread and cereals by 37% and legumes has fallen by 30–80% (5). Recent studies which have analysed dietary patterns rather than specific nutrients suggest that the low intake of grains and cereals together with fresh foods is associated with obesity (6–7). It is therefore pertinent to consider whether increases in these foods might reverse the current upward trend in obesity. A recent study focussed exclusively on increases in fruits and vegetables were able to reduce blood pressure (8), confirming the impact reported by the DASH trial (9), but had no impact on body weight. However, a long-term, randomized dietary intervention trial in patients with cardiovascular disease has shown that a modest 6% point reduction in dietary fat, combined with increases in fish, fruit, vegetables, pulses and nuts, is associated with a weight loss of 4 kg over 1 year and a reduction in cardiac events and mortality by approximately 40% (10). In a recent trial Singh et al. randomized 1000 patients (11). The control group was instructed to follow the National Cholesterol Education Program Step 1 Prudent Diet, which recommends <30% of energy from fat, and less than 10% from saturated fat. The intervention group was instructed to follow the same diet and in addition to consume at least 250–300 g of fruit, 125–150 g of vegetables, 25–30 g of walnuts or almonds, and 400–500 g of whole grains, legumes, rice, maize or wheat. Together this achieved a 3% point reduction in total fat content, together with a significant increase in alpha-linolenic acid. The cardio-protective effect previously reported was confirmed, and the intervention group spontaneously reduced their energy intake, resulting in a weight loss of 3 kg over 2 years. The overall dietary package of reductions in fat intake and an increase in consumption of fish, fruit, vegetables and grains may be critical for the prevention of weight gain and reductions in cardiovascular disease. We conclude that future research and dietary advice to prevent weight gain and obesity should put more emphasis on the foods we do not eat.