Inclusion Criteria:

• Is <6’3” (190.5 cm) tall and weighs <300 lb (~136.3 kg)
• Is obese with a body mass index (BMI) >=30 kg/m^2 to <=45 kg/m^2 and with a history consistent with progressive weight gain and development of obesity not secondary to drastic or traumatic initiating events (e.g., excessive weight gain due to cessation of smoking)
• Is a nonsmoker (never smoked or has not smoked for at least 2 years)
• Does not have a clinical diagnosis of diabetes
• Has not had a major change in daily physical activity within 2 months prior to study start (e.g., initiation of an exercise program)
• Usually consumes three major meals (morning, midday, and evening) each day and rarely (less than once a week) wakes up to eat during the night

Exclusion Criteria:

• Is currently enrolled in a weight loss program or plans to enroll in a weight loss or exercise program within the next 3 months

• Is currently treated or expected to require or undergo treatment or has been treated within 2 months before screening with medications that are excluded:

  • Over the counter antiobesity agents including herbal supplements or prescription antiobesity agents approved for the long-term (including orlistat [Xenical] and sibutramine [Meridia]) and the short-term (including phentermine [Adipex-P, Celltech, Pro-Fast SA, Pro-Fast SR, Fastin, Oby trim, Zantryl, Teramine, Phentride, Phentercot, Obephen, Oby-cap], mazindol [Sanorex and Mazanor], methamphetamine [Desoxyn], diethylpropion [Tenuate and Tenuate Dospan], phendimetrazine [Bontril, Prelu-2, Melfiat 105, Unicelles, X-Trozine, Plegine, Adipost, Obezine, Phendiet-105, PT 105] and benzphetamine [Didrex]) treatment of obesity
  • Systemic steroids by oral, intravenous, or intramuscular route or potent topical steroids that are known to result in high systemic absorption
  • Alpha- or Beta-Blockers, centrally acting sympathicolytic or sympathicomimetic agents, reserpin, guanethidine, etc.
  • Psychotropic medications (e.g., tricyclic antidepressants, monoamine oxidase [MAO] inhibitors, selective serotonin reuptake inhibitors [SSRIs], neuroleptics, lithium, and benzodiazepines)
  • Hypnotic-sedative medications or medications that may affect sleeping behavior including medications containing caffeine
  • Drugs that directly affect gastrointestinal motility, including but not limited to: metoclopramide (Reglan®) and cisapride (Propulsid®); and macrolide antibiotics such as erythromycin and newer derivatives
• Has received any investigational drug within 3 months before study start
• Has participated previously in a study using pramlintide