Studying the Effects of Phentermine on Eating Behavior

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)