Xavier Pi-Sunyer, the Columbia University obesity specialist who ran Sanofi's trials, sees the drug being used mostly for morbidly obese patients, not to help anyone fit into a swimsuit.

FORBES: French drug giant Sanofi prepares for fat city.

Medicare recently put forward a position statement saying that it would pay for gastric bypass in some obese patients.

FORBES: Magazine Article

He said it was unhelpful for doctors to be biased against obese patients.

BBC: NEWS | Health | Fat equals lazy, say doctors

Another strategy involves using less energy (100 kV instead of the standard 120 kV), which is effective but useful only for patients who are not obese.

CNN: Heart test can pack radioactive wallop

Obese patients create more physical work for a surgeon during any type of procedure.

WSJ: Book Excerpt: Confessions of a Surgeon

While obesity is a major risk factor for heart disease as well as other diseases like diabetes and even cancer, obese patients seem to have a survival benefit in certain situations.

FORBES: The 'Obesity Paradox' -- Is It Healthy To Be Overweight?

"People often wonder if obese patients have a worse outcome because they are more inherently at risk for complications, and we did not find that, " he says.

CNN: Obese may be less likely to survive pancreatic cancer

The safety and efficacy of Belviq were evaluated in three randomized, placebo-controlled trials that included nearly 8, 000 obese and overweight patients, with and without type 2 diabetes, treated for 52 to 104 weeks.

FORBES: Arena Obesity Drug Approval Looks Like Best-Case Scenario

The findings raise the alarm that diabetes isn't just a disease of the overweight or obese, says Carnethon, and that physicians should be looking for signs even among their leaner patients, particularly those who are elderly.

CNN: Obesity paradox: Why being thin with diabetes is dangerous

Patients who are obese or obese and diabetic appear to be at an increased risk for cancer, he says.

FORBES: Magazine Article