The results from the National Health and Nutrition Survey (NHANES,1999) estimate that 61% of US adults are either overweight or obese; adult obesity nearly doubled, increasing to 27%, during the 14 years of study [National Center for Health Statistics. NHANES 1999 Prevalence of overweight and obesity among adults: US, 1999. Hyattsville (MD): US Department of Health and Human Services, Public Health Ser- vice, Centers for Disease Control and Prevention; 1999.]
Obesity is an independent risk factor for early mortality. Overall mortality begins to increase with BMI levels greater than 25 and increases most dramatically as BMI levels surpass 30 [Manson JE, Willett WC, Stampfer MJ, et al. N Engl J Med ; 333; 1995; 677-685] The longer the duration of obesity, the higher the risk [Obesity: preventing and managing the global epidemic. Report of a WHO consultation. World Health Organ Tech Rep Ser 2000;894:i-xii, 1–253]. Obesity predisposes a person to coronary artery disease by increasing your blood pressure [hypertension]; producing abnormal lipids; and increasing insulin resistance. In addition to heart disease obesity causes sleep apnea and degenerative joint disease. A modest weight loss of 10% of your body weight will reduce insulin resistance, blood pressure, and decreases abnormal lipid production [Reisin E, Abel R, Modan M, Silverberg DS, Eliahou HE, Modan B.; N Engl J Med ;298; 1978; 1– 6. ][ Wood PD, Stefanick ML, Dreon DM, et al. N Engl J Med ;319; 1173–9.]
I recommend diet and exercise together as the best treatment for obesity. In addition to diet and exercise; the other treatments include pharmacotherapy, behavior therapy and surgery. The surgical approach will discussed in another blog.
A low calorie diet of 500 to 1000 calories below than your maintenance will reduce total body weight by 8% over 3 to 12 months. A very low calorie diet totaling 800 calories per day will produce a very rapid loss of weight but cannot be maintained long term and after one year is not superior to the above low calorie approach. [ClinicalGuidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults–The Evidence Report. National Institutes of Health [published erratum appears in Obes Res 1998;6:464]. Obes Res 1998;6 Suppl 2:51S–209S. ]
Exercise at 60% to 85% of estimated maximum heart rate over 3 to 7 30- to 60-min sessions per week produce a modest amount of weight loss of 3 to 6 lb in one year [A. J. Orzano and J.C.Scott; JABFP 17(5); 2004; 359-369] The benefits of exercise cannot be measured in weight loss alone-as discussed in other sections of this book. The benefit of diet and exercise together provides greater weight loss than either one alone when followed for up to 2 years of study [Skender ML, Goodrick GK, Del Junco DJ, et al.; J Am Diet Assoc 96;1996; 342– 346]. Behavior therapy consists of behavior modification directed toward diet and exercise. This means counseling the patient regarding a healthy lifestyle, setting goals, self-monitoring toward these goals, and will power. It is difficult to evaluate behavior therapy alone since the goal is to get the patient on a diet and exercising.
The final subject is drug therapy. The role of drug therapy in obesity is controversial because most patients regain the weight they had lost when the drug is discontinued. The decision to initiate drug therapy requires in a careful evaluation of risks and benefits. Drugs can help a patient lose body-fat when used with both diet and exercise. Candidates for drug therapy include: those unable to diet and/or exercise; BMI greater than 30 kg/m2; a BMI of 27 to 29.9 kg/m2 with comorbidities such as diabetes and coronary artery disease; those in whom gastrointestinal bypass surgery is being considered.
There are 4 main drug options used in obesity treatment. Lorcaserin is a 5-HT2c receptor agonist that decreases appetite by acting directly on these receptors in the brain. Orlistat is a lipase inhibitor that prevents fat absorption from the gut. Orlistat prevents the absorption of 30% of ingested fat[Hauptman JB, Jeunet FS, Hartmann D., Am J Clin Nutr 55(1]; 1992; 309S–313S]. Orlistat is dispensed as Xenical ,120-mg dose 3 times per day daily. The side effects are substantial and include: stool incontinance, fecal urgency, flatus, and fecal spotting. This is usually the best initial treatment option.
The evidence from the systematic reviews for both Lorcaserin and Oristat is level 2. This is mainly because of the lack of long-term studies and the small changes in weight, approximately 3 lbs to 8lbs at 6 months to 1 year [Smith IG, Goulder MA.. J Fam Pract ;50; 2001;505–512].The third useful drug is Loraglutide-a glucagon like peptide that increases insulin production and decreases appetite. It is useful in patients with both diabetes and obesity. The fourth useful drug treatment is a combination of Phentermine and Topiramate. Phentermine is a stimulant [sympathomimetic amine] that suppresses appetite and Topiramate is an anticonvulsant. This combination may be the most effective in producing weight loss but also has the most complications and cannot be used in patients with hypertension or coronary artery disease. The older-generation noradrenergic appetite suppressants including mazindol, diethylpropion, and phentermine alone are FDA approved for obesity treatment but are not the treatments of choice [Glazer G.; Arch Intern Med 161;2001:1814–1824]. Herbal treatments such as garcinia cambogia, have not been found useful in the treatment of obesity [Heymsfield SB, Allison DB, Vasselli JR, Pietrobelli A, Greenfield D, Nunez C.; JAMA 280;1998:1596– 1600].
My criticism of my medical colleagues is very simple. The FDA approved use of every prescription drug for the treatment of obesity is preceded by the general statement “when diet and exercise do not work”. This statement is never objectively controlled or quantified: how much exercise was performed?; what was the calorie and macronutrient content of the diet?; was there a daily diary?; is the data a subjective verbal report by patient? My colleagues know that the benefits of prescription drug therapy occur only during drug therapy and weaning patients of the drugs leads to weight gain [S. Z. Yanovski and J.A. Yanovski; JAMA311(1);2014; 74-86]. This is the benefit of short-term gain and the frustration of long term loss. No one wishes to change their comfortable life style if they can achieve their goals by taking a pill. Physicians do not have the ability to control the environment in which a patient lives and thus unable to control objectively what a patient eats nor what exercises a patient performs. The successful treatment of obesity requires a long-term life style change and a cultural change –knowledge, diet, and exercise. This does not come inside a bottle of pills.