Dr. Onyeka Nwokocha, a bariatric surgeon at Blount Memorial Hospital, appeared on the noon show. Here are his notes.
The disease of obesity:
•There is still incomplete appreciation for obesity as a disease entity
•In many respects, obesity is not completely preventable in some patient population.
•Nevertheless, the multifactorial contributions to the disease Increases the difficulty in understanding it causes
•The degrees of obesity are defined by body mass index, or BMI (calculated as weight in kilograms divided by height in meters squared), which correlates body weight with height.
•Patients are classified as normal weight( 20-25), overweight (26-29), obese (30-34), severely obese (sometimes referred to as morbidly obese >35 kg/m2), or superObese (BMI of >50 kg/m2)
Prevalence and contributing factors
•The number of Americans adult who are 100 or more pounds over a healthy weight has dramatically gone up over the last 2 decades.
•1980: 25% of Americans were overweight
•1990: that number had risen to 34%
•Current estimate suggests: > 2/3 (68.8% or 157.2 millions) of adults are considered to be overweight.> 1/3 (78.6 million) of adults and 17% of youth in the United States are obese.> 6.6% or 15 million adults are severely obese (BMI >35 kg/m2).
•Despite the expenditure of more than $30 billion annually on weight loss products, the prevalence of obesity is dramatically increasing.
•Obesity is most common in minorities, low-income groups, rural populations, and women, but is increasing in all socioeconomic groups.
The increase in obesity is multifactorial: Genetics plays an important role in the development of obesity. Although the children of parents of normal weight have a 10% chance of becoming obese, the children of two obese parents have an 80 to 90% chance of developing obesity by adulthood.The weight of adopted children correlates strongly with the weight of their birth parents.
Furthermore, concordance rates for obesity in monozygotic twins are double those in dizygotic twins.Diet and culture are important factors as well (the rapid increase in obesity during the past two decades cannot be explained by any genetic cause)
Other factors: Intermittent or consistent excessive caloric intake, lack of satiety, decreased energy expenditure, reduction in the thermogenic response to meals, an abnormally high set point for body weight, and a decrease in the loss of heat energy.
Another factor that may influence absorption of ingested food is the composition of the intraluminal bacteria of the intestinal tract. Recent studies have documented a difference in the composition of the intestinal flora of obese individuals compared with those of normal weight.Concurrent Medical and social problems.
The severely obese patient has chronic-weight related problem: degenerative joint disease, low back pain, hypertension, obstructive sleep apnea, gastroesophageal reflux disease (GERD), cholelithiasis, type 2 diabetes, hyperlipidemia, hypercholesterolemia, asthma, hypoventilation syndrome of obesity, fatal cardiac arrhythmias, right-sided heart failure, migraine headaches, pseudotumor cerebri, venous stasis ulcers, deep vein thrombosis, fungal skin rashes, skin abscesses, stress urinary incontinence, infertility, dysmenorrhea, depression, abdominal wall hernias, and an increased incidence of various cancers such as those of the uterus, breast, colon, and prostate.
However, the single most difficult aspect of the disease of severe obesity for those who have it is the discrimination they face from the rest of the population in terms of social stigmatization.
This prejudice against obesity remains the last type of discrimination without legislative remedyMedical and surgical managment
Lifestyle changes involving diet, exercise, and behavior modification constitute the first tier of therapy for obesity.
•Dietary, exercise, or behavior modification therapy is appropriate treatment for patients who are overweight (BMI <30 kg/m2) and is highly recommended for patients with a BMI between 30 and 35 kg/m2.
•Although success rates are limited with diet and exercise alone, all severely obese individuals are asked to attempt this route of weight loss before undertaking any surgical therapy.
•There are two main reasons for this. The first is to allow those who can achieve such weight loss through the safest possible means to do so. The second, and by far the more practical, is to have the severely obese individual begin to appreciate and practice the lifestyle changes that must ultimately become routine once weight loss is achieved, by whatever means. The adjustment of the patient's lifestyle to include these measures is valuable to long-term success with any bariatric operation.
•Dietary restriction and exercise can each independently create a caloric deficit. A daily energy deficit so created of 500 kcal/d, resulting in a weekly deficit of 3500 kcal, results in the loss of 1 lb of fat weekly. It has been shown that low-calorie diets (800 to 1500 kcal/d) are as effective as very-low-calorie diets at 1 year but result in a lower rate of nutritional deficiencies.
•Such diets may produce an average of 8% body weight loss over a 6-month period. Longer follow-up shows recidivism. Moderate daily physical activity can produce a 2 to 3% body weight loss.
•Pharmacologic therapy is also an option for patients attempting to lose weight. Unfortunately, the number of effective pharmacologic agents is small compared with the number of products sold with assertions that they will promote or support weight loss.
•Pharmacotherapy is normally used only after lifestyle changes and dietary therapies have failed. It is used either alone as the primary therapy or in conjunction with simultaneous diet and exercise therapy.
Currently there are only two drugs approved by the U.S. Food and Drug Administration for the treatment of obesity that promote weight loss. Sibutramine is a noradrenaline and 5-hydroxytryptamine reuptake inhibitor that works as an appetite suppressant. Orlistat inhibits gastric and pancreatic lipase enzymes that promote lipid absorption in the intestine
Either of these drugs may produce a weight loss of between 6 and 10% of body weight after 1 year, but cessation of the drug usually results in prompt regaining of lost weight.
Pharmacotherapy is recommended as an adjunctive or supplementary therapy to lifestyle changes, including diet and exercise or behavioral therapy, by the National Institutes of Health (NIH) consensus guidelines for treatment of obesity.Because medical therapies are almost uniformly ineffective for patients with severe obesity, the severely obese patient (BMI >35) tends to continue to gain weight and the only effective method is surgical