Eligibility Criteria:
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 (ReglanĀ®) and cisapride (PropulsidĀ®); 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