Studying the Effects of Phentermine on Eating Behavior

The Quantification of Ingestive Behavior

The goal of this study is to determine whether one week of phentermine compared to placebo administration results in changes in food intake during a laboratory meal.

This study aims to explore whether short-term measures of eating behavior can be related to later, longer-term weight loss. In a double-blind, randomized fashion, participants will be asked to take study medication for three weeks: one week of phentermine and two weeks of placebo. At the end of the first and third weeks, participants will be asked to participate in a range of eating behavior studies. Following this three-week, double-blind phase, participants will be offered 6 months of open treatment for weight loss.

Inclusion Criteria:

• BMI between 30-40kg/m2
• Stable weight (+5 lbs) for a minimum of 3 months
• Systolic Blood Pressure <140mm Hg
• Diastolic Blood Pressure <90 mm Hg
• Pulse <95 beats per minute
• English language proficiency

Exclusion Criteria:

• Previous unsuccessful trial of phentermine
• Prior adverse reaction to phentermine
• On any antidepressant medications,especially monoamine oxidase inhibitors(MAOI)
• History of neurological disorder (e.g. dementia)
• History of moderate or severe head injury
• Current or past history of coronary artery disease
• Current or past history of stroke or transient ischemic attack
• Current or past history of heart arrhythmias
• Current of past history of congestive heart failure
• Current or past history of peripheral artery disease
• Current or past history of liver disease
• Current or past history of kidney disease
• Uncontrolled diabetes mellitus (type I or II)
• Narrow-angle glaucoma
• Hypo- or hyper-thyroidism not adequately treated
• On medications (prescribed or OTC) known to affect appetite (e.g. diet pills), weight, or metabolism
• Current or past history (within the past 12 months) of major depression
• Current or past history (past 12 months) of alcohol or drug abuse or dependence
• Current or past history (lifetime) of amphetamine abuse or dependence
• Known history of learning disorder or developmental disability
• Current or past Attention Deficit Hyperactivity Disorder (ADHD)
• Pregnancy, planning to become pregnant, or lactation within the previous 6 months
• Waist circumference greater than 188cm
• Indwelling metallic object (e.g., pacemaker,pump), non-removable metal jewelry, medicinal patch or recent metallic ink tattoo
• Significant claustrophobia
• Current or past history of anorexia nervosa,bulimia nervosa (within the past 12 months) or binge eating disorder (within the previous 6 months)