Getting to the heart of the matter: The new obesity and lifestyle guidelines
As clinicians, we are not as aggressive at counseling our overweight and obese patients about diet, exercise and weight loss during the upcoming holiday season. The newly released 2013 American College of Cardiology/American Heart Association/The Obesity Society Guideline for the Management of Overweight and Obesity in Adults and ACC/AHA Guideline on Lifestyle Management to Reduce Cardiovascular Risk address critical issues such as weight loss, cut-points for BMI and waist circumference, diets, comprehensive lifestyle intervention programs and bariatric surgery.
Focus on overweight and obesity
As in past guidelines, clinicians are advised to calculate body mass indices and measure waist circumference at annual visits. BMI of 25 to 29.9 is used to identify overweight individuals, and BMI ≥30 to identify obese adults. Overweight or obese patients should be counseled that their BMI level places them at increased risk for CVD, type 2 diabetes and mortality.
Clinicians should also emphasize that modest weight loss (3% to 5% of body weight) can result in clinically meaningful benefits for triglyceride and blood glucose levels. Greater weight loss (>5%) can further reduce BP, improve lipids (both LDL and HDL), and reduce the need for medications.
The obesity guideline also focuses on the benefits of participation in comprehensive lifestyle programs for weight loss. It recommends any program that helps participants adhere to reduced-calorie diets and increased physical activity (200 to 300 minutes/week). The ideal program would include on-site high-intensity sessions and individual/group sessions by a trained interventionist for at least 1 year.
Electronically delivered weight-loss programs such as telephone- and commercial-based programs are acceptable, provided there is peer-reviewed published evidence of safety and efficacy. However, these programs often result in smaller weight loss than face-to-face interventions.
The guideline suggests several possible methods to reduce food and calorie intake:
Bariatric surgery is an option for adults with a BMI ≥40 or BMI ≥35 with obesity-related conditions who have not responded to behavioral treatments with or without pharmacotherapy. There is insufficient evidence to recommend for or against undergoing bariatric surgical procedures for individuals with a BMI <35.
Regardless of the weight-loss method, maintenance should be a key component of patients’ overall plan. Long-term (≥1 year) comprehensive weight-loss maintenance programs are strongly recommended, including regular contact with trained personnel, face-to-face or telephone-delivered, to encourage high levels of physical activity (200 to 300 minutes/week), monitor body weight (at least weekly) and adhere to a reduced-calorie diet.
Emphasis on diet, physical activity
The new lifestyle guideline is consistent with the obesity guideline. Based on a systematic evidence review, it emphasizes the importance of heart-healthy dietary patterns and physical activity level even in the absence of weight change on CVD risk. It advises adults who would benefit from LDL and BP lowering to consume a healthy diet consisting of vegetables, fruits and whole grains, as well as low-fat dairy products, poultry, fish, legumes, non-tropical vegetable oils and nuts, with limited sweets, sugar-sweetened beverages and red meat.
The panel of experts did not consider any specific diet to be superior to others, but recommend choosing a diet composition based on the patient’s personal and cultural food preferences as well as health status. Patients who would benefit from LDL lowering should reduce saturated and trans fat intake and aim for a dietary pattern that achieves 5% to 6% of calories from saturated fat. Patients who need to lower their BP should decrease their sodium intake by at least 1,000 mg/day. Ideally, adults should consume no more than 2,400 mg sodium/day. If they can restrict their sodium intake to 1,500 mg/day, there is an even greater reduction in BP. Moderate-to-vigorous aerobic physical activity, three or four sessions a week for 40 minutes per session, can reduce LDL, non-HDL and BP.
‘Perfectly timed’ guidelines
The panel of experts did an excellent job with these guidelines. There were a few omitted topics that would have been interesting for them to review. The obesity committee acknowledged that they did not delve into the genetics of obesity, binge-eating disorders, pharmacotherapy and cost-effectiveness of obesity interventions. These subject areas are complicated, and there is no consensus opinion on many of them. Neither guideline went in depth about factors and interventions that make patients more or less likely to lose weight or maintain lifestyle changes. Most experts agree that health status affects a patient’s ability to be successful.
One of the most prominent omissions is the new, exciting developments in health technology such as the text-message programs, smartphone apps and online websites that make it easier for patients to track caloric intake and physical activity. Early data suggest that some of these interventions have a positive effect on weight loss. Those tools, if constructed and guided by evidence-based content, show promise in helping people sustain healthy behaviors. It would have been useful if the committee had discussed these topics as areas of future research to improve health outcomes.
Overall, the perfectly timed 2013 guidelines are reminders that clinicians should encourage overweight and obese patients to lose weight and modify their lifestyles to reduce their risk for atherosclerotic CV events.
Read more guideline commentary here