The purpose of this study is to evaluate the effect of lorcaserin on energy metabolism and food intake in obese and overweight patients.

Inclusion Criteria:

1. Males or females aged between 18 and 65 years (inclusive)
2. Body Mass Index (BMI) is 27.0 to 45.0 kg/m2, inclusive
3. Able to give signed informed consent
4. Ambulatory and able to perform exercise program (Arena Healthy Lifestyle Program, see Appendix 1)
5. Eligible male and female patients must agree not to participate in a conception process
6. Considered to be in stable health in the opinion of the Investigator

Exclusion Criteria:

1. Prior participation in any study of lorcaserin.

2. Participants who are current smokers or have smoked within the previous 6 months. No smoking will be allowed during the study.

3. Clinically significant new illness in the 1 month before screening

4. Not suitable to participate in the study in the opinion of the Investigator including an existing physical or mental condition that prevents compliance with the protocol

5. Recent history (within 6 months before entering the study) of major depression, anxiety, or other psychiatric disease requiring treatment with prescription medication. SSRI's, SNRI's, and other medications must meet washout requirements.

6. Significant dislike or allergy to foods used during the food intake tests

7. History of any of the following cardiovascular conditions:

   • Myocardial infarction (diagnosed by cardiac enzyme[s] and/or diagnostic ECG), CVA, TIA or RIND within 3 months of screening; cardiac arrhythmia requiring medical or surgical treatment within 3 months of screening
   • Unstable angina
   • History of congestive heart failure caused by insufficiency, damage, or stenosis of any heart valve
   • History of pulmonary artery hypertension

8. Positive result of HIV, hepatitis B or hepatitis C screens

9. Recent treatment (i.e., within 1 month of the screening visit) with over-the-counter weight loss products or appetite suppressants (including herbal weight loss agents), or within 3 months with a prescription anti-obesity drug (e.g., phentermine, sibutramine, orlistat)

10. Participated in any clinical study with an investigational drug, biologic, or device within 1 month prior to screening