In the first update to national guidelines on treating obesity since 1998, the American Heart Association and the American College of Cardiology worked together to evaluate and synthesize 133 clinical research trials on how to best lose weight to achieve the healthiest outcomes. The guidelines, released earlier this week, serve as a roadmap addressed to primary care physicians on how to treat obesity, but contain valuable information for anyone seeking to lose weight.

The best approach: start treating obesity as a disease. The American Medical Association re-classified obesity as a disease earlier in July, but these guidelines published simultanously in Circulation, a journal of the American Heart Association; the Journal of the American College of Cardiology; and Obesity, the Journal of The Obesity Society are the first recommendations on how to treat it as a disease.

While obesity itself may not be the direct cause of death, the number of life-threatening diseases it indirectly causes is cause for alarm. Obesity raises the risk of hypertension, dyslipidemia (high cholesterol), type 2 diabetes, coronary heart disease, stroke, gallbladder disease, osteoarthritis, sleep apnea, respiratory problems, and a number of cancers. Extra weight isn’t just associated with a heightened risk for disease, but an increased risk of death too. Obesity is associated with an increased risk in all-cause and cardiovascular disease mortality.

The first step in applying the guidelines is to determine body mass index, which is roughly a ratio of your weight adjusted to your height. You can calculate your BMI using a BMI calculator. A BMI from 25-29.9 is considered overweight, while a BMI above 30 is considered obese.

The guidelines recommend that providers target patients who are obese or overweight patients with confounding risk factors, including comorbidities of type 2 diabetes, hypertension, hyperlipidemia, or large waist circumference.

Providers and patients should work together to find a plan that works best to lose weight. Health benefits could be seen after losing as little as a 3 percent weight loss, but more dramatic benefits could be observed by losing as much as 10 percent of body weight. For example a 5 foot 5 inch person at 180 pounds is obese, but could lower their risk of developing diabetes and some cancers, just by reducing their weight to 162 pounds.

Weight Loss Plans: Diet And Exercise Remain Key

Exactly what makes a weight-loss plan good is nothing surprising: changes in diet, exercise, plus behavioral weight-loss counseling.

Even after reviewing seventeen different diets, authors did not find a single diet that works for everyone. But authors did find, in general, the best weight loss results are achieved when people consume at least 500 calories less than their normal diet.

"There is no ideal diet for weight loss, and there is no superiority between the many diets we looked at," lead author Dr. Donna Ryan said in an interview with USA Today. "We examined about 17 different weight-loss diets. There are many dietary paths to weight loss, as long as you are creating a calorie deficit."

Ryan recommended that people select a diet that addresses other risk factors. For instance, someone with high blood pressure (hypertension) should follow the low-sodium DASH diet, while people with high cholesterol should try diets low in cholesterol and saturated fats. Even the controversial high-protein low-carb Atkins diet, evidently might help some achieve weight loss.

Weight Loss Interventions With Face-To-Face Counseling

Most interesting guideline is the recommendation that obese and high-risk overweight patients enroll in weight loss interventions that incorporate face-to-face meetings with trained interventionists to create new menus, set realistic fitness schedules, and change other unhealthy behaviors. The best interventions include two to three in person meetings over six months, with follow up over the course of a year. People looking to lose weight might also benefit from commercial weight-loss programs, such as Weight Watchers or the YMCA’s Weight Loss For Life, or other programs involving counseling over the phone or the Internet.

One of the most concrete benefits resulting from these guidelines is that insurers will now be more likely to reimburse for these interventions, now that the medical community can agree that they’re good for patients. Last year, Medicare began covering behavioral counseling for obese people, and most private insurance companies are expected to cover this and other obesity treatments by next year, thanks in part to the Affordable Care Act.

The guidelines also recognized that weight loss drugs and surgeries might prove helpful, but should only be used by very high-risk people once first-line measures of diet, exercise, and counseling fail. Bariatric surgery, for instance, is recommended for people with BMIs greater than 35, or those with BMIs greater than 30 that have comorbidities such as diabetes and hypertension.

While the content of the guidelines — weight loss is best achieved by diet, exercise, and behavior modification — is far from earth shattering, the advent of major medical organizations empowering doctors across the nation to be more aggressive in getting patients to lose weight is. With over one-third of adults and nearly one-fifth of children in the United States qualifying as obese, don’t be surprised if your doctor tells you to spend some extra time on a treadmill next time you’re in the office.

"It's an enormous shift," said Ryan in an interview with MedPage Today. "The current way [primary care clinicians] engage obese patients, if at all, is to tell them to lose weight. They recommend weight loss, but they don't own weight management."

Source: 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and The Obesity Society. Obesity (Silver Spring). 2013