Diet, Weight Loss, and Lifestyle: Change Requires Some Heavy Lifting
Bove Corner | My usual office litany starts with a comment on weight, an explanation of body mass index (BMI) and the national standards on what is a normal BMI, a brief lesson on the thermodynamics of energy flow through the body, and comments on lifestyle and diet to achieve target BMI goals. The BMI target is usually not 23 or 24; that may be optimal but it is, frankly, a discouraging, extreme, out-of-reach goal for most patients. Rather, I talk about getting below a BMI of 30, where they are no longer considered "obese"; that's usually a good place to start. Besides, being "overweight" isn't nearly as negative a condition as being "obese," and we have data that a BMI in the 26-28 range might be healthy for some patients with chronic disease and the elderly.
Recent literature suggests that the real issue in obesity is not energy balance but the inability to regulate food intake. While I understand the problem with appetite control, leptins, etc., the energy balance defined by the physics and thermodynamics of weight doesn't change: if a patient can significantly reduce food (energy) intake relative to energy utilization, weight will go down. It's more complicated than that, however, as evidence accumulates that voluntary behavior is not the whole story; there are hormones and other regulatory proteins that counter the need to reduce energy intake to reach a negative energy balance and metabolize the energy stored in the form of adipose tissue. We see strong evidence, for example, that once one reaches a BMI >40 (extreme obesity), the combination of hormonal and behavioral factors make it nearly impossible to achieve an ideal weight by diet alone. We see and read about individual successes, but the great majority of obese patients are often unable to reach their goal without substantial help.
The number of bariatric surgical procedures aimed at reducing food intake or food absorption has increased significantly (and was the topic of the June 2013 CSWN cover story: "Bypassing Obesity"). The procedures are successful, but all bariatric programs start with efforts to motivate the patient to achieve weight reduction before the surgery because it remains quite possible to continue to consume too much food even after the surgery, thus losing the value of the bariatric procedure. Organized weight reduction programs that rely on exercise and food coaches, group motivation, prepared meals, and frequent surveillance of weight status do work. For many patients the cost is prohibitive, but with proper motivation, these programs can succeed in initial weight reduction and sustained weight control.
An important step in getting patients motivated to lose weight is to recognize the overweight or obese patient in the office and comment on the benefits of weight reduction. Many of these patients develop diabetes and there is good evidence that weight loss improves glucose intolerance, lowers A1c, and reduces the risk for atherosclerosis and its complications. All available risk calculators suggest that the presence of diabetes increases cardiovascular disease risk substantially. Explaining BMI, metabolic syndrome, and diabetes and its complications is an important part of patient motivation. If the overweight or obese patient gets through an office visit for hypertension, atrial fibrillation, coronary disease, etc. without a comment from their cardiologist, most will interpret the lack of interest as tacit acceptance of their current weight status.
Should we take an active role in developing a weight reduction strategy for our patients? I find that I am not very convincing with just an office visit and some advice. We all advise more exercise and less food, but that alone is not adequate to accomplish sustained weight reduction. Should we prescribe diet pills? You'll see in this month's cover story that new drugs are available but their sales are missing expectations. That may be a result of well-publicized failures of previous weight loss drugs as well as the fact that many of our patients have chronic cardiac conditions that complicate their use. Also, without an organized weight reduction program, these drugs are not very effective.
There are no simple solutions and, usually, it requires more than an individual practice can offer. A team approach that involves continuous surveillance and communication, group motivation, exercise, even meal preparation coaching begs for an organized, integrated program in which a patient can participate long term to sustain reduced weight. As numerous commercial programs exist that accomplish these goals, our role in patient care is best achieved by developing a liaison with such efforts and with bariatric surgery programs to give patients specific instruction on recommended programs and to provide continuous motivation.
We continue to see more patients with cardiovascular complications of obesity. To reduce these complications, improve overall health, and increase longevity, we need to first recognize the problem in our patients and motivate them to take action, but not expect the brief advice we provide in the office to solve the problem. Hopefully, our healthcare system will recognize the value of these organized programs in reducing long-term healthcare costs, and provide more financial support to allow our patients to achieve their weight goals and improve their health.
Alfred A. Bove, MD, PhD, is professor emeritus of medicine at Temple University School of Medicine in Philadelphia, and former president of the ACC.
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