So it is no surprise that some overweight people, the doctors who treat them, Wall Street and Pharma are heartened by the FDA’s approval this summer of two new diet drugs. Qsymia, made by Mountain View, CA-based Vivus and Belviq, made by San Diego-based Arena Pharmaceuticals were both turned down by the FDA in 2010 but reconsidered and approved this year when more safety data were presented. Both are expected to hit pharmacy shelves before the end of the year.

Qsymia combines the diet pill phentermine (also known as Fastin, Adipex and Ionamin) with topiramate, the active ingredient in the seizure drug Topamax known to suppress appetite. Even though both ingredients are already on the market and could be prescribed without Qsymia’s approval, the FDA rejected the combo pill two years ago over concerns about depression, memory-loss and birth defects risks. (Months after Qsymia’s 2010 rejection, the FDA added a birth-defect warning to topiramate.)

Belviq is lorcaserin, a never-before-approved antidepressant-like drug similar to two drugs withdrawn from the market for deadly heart valve problems in 1997. The FDA rejected Belviq in 2010 because of tumors in rats given the drug, causing Arena to lay off 66 employees and prompting a petition to the FDA charging that, “The dramatic elevation of concern over rat cancer,” could “result in irreparable damage to the bio-technology and pharmaceutical industry as a whole.”

Of course, dangerous diet drugs have also caused “irreparable damage to the bio-technology and pharmaceutical industry,” which is why the FDA has been so gun-shy about approving a new diet med. Fen-Phen, which combined phentermine (found in the just-approved drug Qsymia) and dexfenfluramine or fenfluramine (similar to the just-approved Belviq) was withdrawn as a combination drug in 1997 for causing primary pulmonary hypertension (PPT) and heart valve deaths. The drug’s lethal side effects were especially embarrassing to the FDA since its own reviewer had predicted them if the two drugs were combined but his veto was overridden and the drug was approved anyway. Oops.

The same year Fen-Phen was withdrawn, the FDA approved the diet drug sibutramine (Meridia) which was also withdrawn from the market in 2010 for cardiovascular problems! In fact, the appetite reducing action of diet drugs and heart problems can be so closely linked an FDA advisory committee voted earlier this year to require all obesity drugs to undergo more stringent clinical trials to assess cardiovascular risks.

Now, the FDA is taking no chances with the newly approved drugs. “Qsymia can increase heart rate; this drug’s effect on heart rate in patients at high risk for heart attack or stroke is not known. Therefore, the use of Qsymia in patients with recent (within the last six months) or unstable heart disease or stroke is not recommended. Regular monitoring of heart rate is recommended for all patients taking Qsymia, especially when starting Qsymia or increasing the dose,” said the FDA in approving the new diet pill. Similar warnings appear for Belviq.

Both drugs are strictly approved for adults with “initial body mass index (BMI) of 30 kg/m2” and other obesity-related risks factors–not for people who are a size 4 and want to be a size 2. They are also approved as “adjuncts to reduced-calorie diet and increased physical activity for chronic weight management,” meaning that patients have to do some of the heavy lifting too. And patients are cautioned to not stay on the drugs if they aren’t working and to have close doctor supervision even when they are.

To keep “pill mills” from sprouting up with the new drugs as they did in the 1990s to cash in on the popularity of Fen-Phen before it was withdrawn, the FDA has also tightened the new drugs’ availability. Doctors must prescribe Qsymia through a certified pharmacy and cannot stock it themselves reports NBC News and Belviq will likely be controlled by the Drug Enforcement Administration (DEA) like opiate painkillers.

How well will the new drugs actually work? In clinical trials, Qsymia users lost up to 10 percent of their total body weight. Besides the appetite suppressing phentermine, Qsymia contains topiramate which users actually complain makes them lose too much weight because it makes food and beverages taste bad. Of course the 10-percent weight loss comes at the price of a risk of birth defects, a warning that is clearly marked.

In clinical trials, Belviq users lost up to 5 percent of their total body weight, considerably less than with Qsymia. But some are predicting doctors or patients may add phentermine to Belviq and create a neo Fen-Phen since Belviq’s ingredient is similar to the withdrawn ingredient Fen-Phen. Few liked the drowsiness, memory loss and mood changes caused by the withdrawn “fen” drug but when phentermine (now in Qsymia) was added, it counteracted the effects and maximized the weight loss. Anticipating the desire on the part of patients or doctors to reconstitute a Fen-Phen, Belviq’s prescribing information warns against “coadministration” of other weight-loss drugs and even mentions phentermine by name. Certainly the warning covers topiramate (the other ingredient in Qsymia)–as well as taking all three active ingredients together.

It is not clear whether insurance will cover Qsymia and Belviq, which are projected to cost $100 to $200 a month (or more). Despite the well-documented expenses of treating obesity-related health problems, Medicare doesn’t cover diet drugs, reports the industry site FiercePharma. Few state Medicaid programs cover diet drugs either and private insurers often ask patients to share the cost.

Like alcoholics who can never drink normally again, many obese people will not return to “normal” eating even if their weight becomes normal through the use of diet pills, say eating behavior specialists. They need to change their whole relationship to food. Even those who learn “normal eating” are up against the so-called “thrifty gene” that confounds the body by keeping it at a plump “set point” regardless of how low calorie intake goes. Waiting for blockbuster diet drugs pills to solve such life-long struggles is unrealistic, most say.

In fact, testimony about Qsymia in 2010, when it was first considered, confirmed the problem. Erin Aycock, an obesity patient who spoke during the open-microphone portion of FDA hearings, told the advisory committee that Qsymia was “like instant willpower,” and that she “had the ability for the first time in my life to say ‘I don’t even care if I eat that cookie.'” But that was the good news. Aycock also added that 90 percent of the weight she had lost on Qsymia quickly returned when she quit the drug.