Harrison's Internal Medicine Chapter 75. Evaluation and Management of Obesity
Evaluation and Management of Obesity: Introduction Over 66% of U.S. adults are currently categorized as overweight or obese, and the prevalence of obesity is increasing rapidly throughout most of the industrialized world. Based on statistics from the World Health Organization, overweight and obesity may soon replace more traditional public health concerns such as undernutrition and infectious diseases as the most significant contributors to ill health.
Lifestyle Management Obesity care involves attention to three essential elements of lifestyle: dietary habits, physical activity, and behavior modification. Because obesity is fundamentally a disease of energy imbalance, all patients must learn how and when energy is consumed (diet), how and when energy is expended (physical activity), and how to incorporate this information into their daily life (behavior therapy). Lifestyle management has been shown to result in a modest (typically 3– 5 kg) weight loss compared to no treatment or usual care.
The three restrictive-malabsorptive bypass procedures combine the elements of gastric restriction and selective malabsorption. These procedures include Roux-en-Y gastric bypass (RYGB), biliopancreatic diversion (BPD), and biliopancreatic diversion with duodenal switch (BPDDS) (Fig. 75-2). RYGB is the most commonly performed and accepted bypass procedure. It may be performed with an open incision or laparoscopically.
Childhood obesity has been one of the major problems for children in the last century
and it still is a widespread condition all over the world. The metabolic effect of early-
onset obesity is more severe in children than in adults. This process may start in early
infancy or even in the uterus. Obesity in children is a very complex and difficult issue for
endocrinologists. This book aims to draw attention to the various aspects of this disease.
The Adipocyte and Adipose Tissue Adipose tissue is composed of the lipid-storing adipose cell and a stromal/vascular compartment in which cells including preadipocytes and macrophages reside. Adipose mass increases by enlargement of adipose cells through lipid deposition, as well as by an increase in the number of adipocytes. Obese adipose tissue is also characterized by increased numbers of infiltrating macrophages.
Physical Activity Therapy Although exercise alone is only moderately effective for weight loss, the combination of dietary modification and exercise is the most effective behavioral approach for the treatment of obesity. The most important role of exercise appears to be in the maintenance of the weight loss. Currently, the minimum public health recommendation for physical activity is 30 min of moderate intensity physical activity on most, and preferably all, days of the week.
Harrison's Internal Medicine Chapter 74. Biology of Obesity
Biology of Obesity: Introduction
In a world where food supplies are intermittent, the ability to store energy in excess of what is required for immediate use is essential for survival. Fat cells, residing within widely distributed adipose tissue depots, are adapted to store excess energy efficiently as triglyceride and, when needed, to release stored energy as free fatty acids for use at other sites.
For many years obesity in rodents has been known to be caused by a number of distinct mutations distributed through the genome. Most of these singlegene mutations cause both hyperphagia and diminished energy expenditure, suggesting a physiologic link between these two parameters of energy homeostasis. Identification of the ob gene mutation in genetically obese (ob/ob) mice represented a major breakthrough in the field. The ob/ob mouse develops severe obesity, insulin resistance, and hyperphagia, as well as efficient metabolism (e.g.
Although obese patients commonly have central obesity, hypertension, and glucose intolerance, they lack other specific stigmata of Cushing's syndrome (Chap. 336). Nonetheless, a potential diagnosis of Cushing's syndrome is often entertained. Cortisol production and urinary metabolites (17OH steroids) may be increased in simple obesity.
Prevalence Data from the National Health and Nutrition Examination Surveys (NHANES) show that the percent of the American adult population with obesity (BMI 30) has increased from 14.5% (between 1976 and 1980) to 30.5% (between 1999 and 2000). As many as 64% of U.S. adults ≥20 years of age were overweight (defined as BMI 25) between the years of 1999 and 2000. Extreme obesity (BMI ≥40) has also increased and affects 4.7% of the population. The increasing prevalence of medically significant obesity raises great concern.
A central pathway through which leptin acts to regulate appetite and body weight. Leptin signals through proopiomelanocortin (POMC) neurons in the hypothalamus to induce increased production of α-melanocyte-stimulating hormone (α-MSH), requiring the processing enzyme PC-1 (proenzyme convertase 1). α-MSH acts as an agonist on melanocortin-4 receptors to inhibit appetite, and
the neuropeptide AgRp (Agouti-related peptide) acts as an antagonist of this receptor. Mutations that cause obesity in humans are indicated by the solid green arrows.
The average total daily energy expenditure is higher in obese than lean individuals when measured at stable weight. However, energy expenditure falls as weight is lost, due in part to loss of lean body mass and to decreased sympathetic nerve activity. When reduced to near-normal weight and maintained there for a while, (some) obese individuals have lower energy expenditure than (some) lean individuals. There is also a tendency for those who will develop obesity as infants or children to have lower resting energy expenditure rates than those who remain lean.
Background: Dercum’s disease (DD) is characterised by obesity and chronic pain ( 3 months) in the adipose tissue. The pathogenesis of DD is unknown, but inflammatory components have been proposed. In previous reports and studies, an inconsistent picture of the histological appearance of the adipose tissue in DD has been described. The aim of this investigation was to examine the histological appearance of adipose tissue in patients with DD, with particular focus on inflammatory signs. Methods: Fat biopsies were sampled from painful regions from 53 patients with DD.
the human body needs nutrients to 3 as calcium, iron and zinc in the juvenile stage. In addition to providing nutrients, the split meals a day, eat slowly and chew very positive effects help this little group of obesity and diseases related to metabolism.
Regulation of energy homeostasis is mainly mediated by factors in the
hypothalamus and the brainstem. Understanding these regulatory mecha-nisms is of great clinical relevance in the treatment of obesity and related
Obesity and related metabolic diseases, such as type 2 diabetes, hyperten-sion and hyperlipidemia are an increasingly prevalent medical and social
problem in developed and developing countries. These conditions are asso-ciated with increased risk of cardiovascular disease, the leading cause of
Obesity and its associated disorders, including diabetes and cardiovascular
disease, have now reached epidemic proportions in the Western world,
resulting in dramatic increases in healthcare costs. Understanding the pro-cesses and metabolic perturbations that contribute to the expansion of adi-pose depots accompanying obesity is central to the development of
appropriate therapeutic strategies.
Previous studies have found that adverse effects of maternal employment on child obesity are limited to mothers with higher education and earnings. Explanations for this have centered on differences between the childhood nutritional and exercise environments provided by non-parental caregivers versus by the mothers.
(BQ) Childhood obesity has become a very common condition and can often lead to serious physical and emotional complications as the child grows up. If you are the parent, caregiver, or loved one of a child who is battling obesity, 100 Questions & Answers About Your Child’s Obesity can offer help. This book is an authoritative and user-friendly guide that will enhance your knowledge of this condition and answer your questions about causes, diagnosis, treatment options, and the prognosis for children with obesity.