Few companies are placing all their bets on the obesity market, but several biotechs are working on diseases that can be caused by being overweight, such as diabetes and cancer. For instance, OSI Parmaceuticals ( OSIP), best known for marketing the cancer drug Tarceva with Genentech ( DNA), has a subsidiary focused on obesity and diabetes called Prosidion. The division is developing drugs that target the high blood-sugar levels that contribute to the diseases. Another company, Myriad Genetics ( MYGN), has discovered a gene linked to an overeating disorder called hyperphagia and early onset obesity. The latter dramatically increases one's risk of developing Type 2 diabetes, a condition that's growing in proportion with cases of obesity. Nastech Pharmaceutical ( NSTK) has jumped into the field with its recent acquisition of certain patents from Cedars-Sinai Medical Center to support an investigational nasal spray for obesity. The spray contains a hormone that regulates appetite control, and it's currently in three early-stage trials on its safety and tolerability. If it's ultimately successful, the drug will be marketed by Merck ( MRK). Meanwhile, Icoria ( ICOR), a company with a $10 million market capitalization that trades on the over-the-counter Bulletin Board, has also heard the calling of the obesity market. Originally focused on agriculture under the name Paradigm Genetics, Icoria sold off its plant research unit to focus on developing obesity and diabetes treatments. The company has agreed to be acquired by Clinical Data ( CLDA), a blood products and services company. Wittes says other companies may eventually broaden the field, perhaps makers of neurostimulation devices such as Cyberonics ( CYBX) and Boston Scientific's ( BSX) Advanced Bionics, though neither company has made any announcements to that effect. At any rate, as with ordinary weight-loss techniques, only time will tell if the new crop of obesity fighters can keep the weight off.