Great data, VIVUS (Nasdaq: VVUS) and Orexigen (Nasdaq: OREX). There's just one problem; I can't see how it's going to get your drugs approved.

Both companies presented data on their obesity drugs at the American College of Cardiology meeting yesterday. After two years on VIVUS's Qnexa, patients reduced their triglycerides, improved their good cholesterol levels, and a reduced the use of antihypertensive medications compared to placebo. Orexigen's Contrave similarly increased good cholesterol and decreased a marker for heart disease.

Sounds great. Both companies were up by double digits at some point yesterday. Unfortunately all the trials seem to do is reinforce the idea that losing weight is good for you and improves heart-related issues. There's no evidence that the drugs are having a direct effect on the cardiovascular system. Instead, the effect seems to be a side effect of losing weight. If you put patients onto a treadmill for four hours a day, you'd likely get the same effect.

And the weight loss from exercise would come without the side-effect worries that come with Qnexa and Contrave. The Food and Drug Administration has requested data from VIVUS about cleft lip seen in babies born to women taking one of the components of Qnexa. And the FDA wants an additional heart study -- oh, the irony -- for patients taking Contrave.

Personally, I think the risks justify the weight loss. I'd just approve them both along with Arena Pharmaceuticals' (Nasdaq: ARNA) loracaserin. Heck, bring back Abbott Labs' (NYSE: ABT) Merida, and let Pfizer (NYSE: PFE) relaunch Fen-Phen if it wants. Just tell patients the potential risks and let them decide for themselves whether they should take the drug.

Unfortunately, I neither work at the FDA nor does the agency share my Libertarian views of drug approvals. It's highly unlikely that the new data will do anything to change the FDA thinks about the risk-benefit analysis of the drugs.

Investors willing to risk putting their portfolios on a diet can go ahead and take a flyer on VIVUS or Orexigen. The rest of us should wait until the side-effect lady sings before jumping on board.

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Pfizer is a Motley Fool Inside Value recommendation. The Fool owns shares of Abbott Laboratories. Motley Fool Alpha LLC owns shares of Abbott Laboratories. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.

Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. The Motley Fool has a disclosure policy.