PHILADELPHIA — For patients trying to lose weight, meal replacement products boost the odds of success, according to Dr. Robert F. Kushner, a professor in the department of medicine at Northwestern University, Chicago.
In a recent study, the most important predictors of successful weight reduction were found to be number of physician counseling sessions attended, use of meal replacement products, and minutes of weekly activity (Obesity 2009;17:713–22).
When used to replace one or two meals per day, meal replacement products—including bars, liquid shakes, and frozen dinners—have been shown to increase weight loss (Diabetes Care 2007;30:1374–83). “If you don't use [meal replacements], I would encourage you to start recommending [them] because it's evidence-based outcomes. It works,” said Dr. Kushner, president of the Obesity Society and author of two books on weight loss.
These products help patients cut caloric intake, and the key to managing obesity is “calories, calories, calories,” he said at the annual meeting of the American College of Physicians.
Any diet that restricts calories results in the same average amount of weight loss, regardless of the ratio of fat, carbohydrates, and protein (N. Engl. J. Med. 2009;360:859–73). “Any diet will work, as long as you follow the diet,” and it's important to get that message out to patients, he said.
Weight loss is especially important for patients with diabetes or prediabetes. In one study, a program of weight loss and exercise led to a 58% reduction in diabetes risk, compared with 31% with metformin alone (N. Engl. J. Med. 2002;346:393–403). Diabetes is improved even if patients regain weight, Dr. Kushner added, so “it's better to have lost weight and regained it than never have lost it at all.”
Exercise alone “is not a very effective modality for weight loss,” he noted. “The amount of calories that you'd actually have to burn off in exercise is huge—much more than people actually think.”
Although adding exercise to calorie restriction does not result in significantly greater short-term weight loss (Med. Sci. Sports Exerc. 1999;31[suppl]:S547–52), it can be effective over the long term to keep weight down, especially if the patient engages in at least 200 minutes of moderately vigorous activity a week (JAMA 1999;282:1554–60). “It is one of the most effective components to keep weight off,” perhaps because it allows some “wiggle room” in calorie intake, he said.
Pharmacotherapy alone is also not very effective, yielding an additional weight loss that's generally less than 5 kg at 1 year (Ann. Int. Med. 2005;142:525–31), and most patients will lose only 5% of their body weight on medication alone. However, that may rise to 8%-15% if they also make lifestyle changes. Patients should be counseled about the importance of combining medication with diet and exercise, Dr. Kushner said. Available drugs include phentermine, sibutramine, and orlistat.
“The last time a medication was approved in this country for obesity care was 10 years ago” when orlistat was approved, but several experimental agents have shown promise, he said. Newer-generation obesity drugs now in trials are taking “a whole new direction in obesity care” by harnessing natural peptides, including peptide YY and glucagonlike peptide-1 analogues.
Bariatric surgery is the last option to consider. “Internists clearly have a role in identifying and treating and referring patients and managing [bariatric surgery] patients, so it's imperative [to] have a familiarity with these procedures,” Dr. Kushner said.
For selected patients, especially those with comorbidities, “the outcomes are really quite spectacular,” he added. “Diabetes is gone in three out of four patients that have bariatric surgery.” Hyperlipidemia, hypertension, and sleep apnea often improve or resolve after surgery.