Effects of Intravenous Infusions of Gut Hormones on Appetite and Metabolism.

INGEAR-1: Effects of INtravenous Infusions of PYY3-36 and GLP-1, as Monoinfusion and in Combination, on ad Libitum Energy Intake, Appetite Sensation, and Energy Expenditure in Healthy Obese Subjects.

The purpose of this study is to investigate the effects of intravenous infusion of two gastrointestinal hormones, PYY3-36 and GLP-1, alone and in combination, on appetite in healthy obese men. The investigators hypothesize that an intravenous infusion of each hormone alone will decrease food intake at a buffet meal and decrease appetite, and that in combination, there will be a greater decrease in food intake and appetite compared to each hormone alone.

Inclusion Criteria:

• Men age 18-50 years
• BMI ≥30
• healthy

Exclusion Criteria:

• Diabetes mellitus
• psychological illness
• on special diets (eg vegetarian, Atkins)
• weight change of >3kg within the 2 months prior to screening
• Hypothalamic or genetic aetiology of obesity
• diagnosed cancer
• chronic illness or disease
• Eating disorder (anorexia or bulimia)
• smoking
• substance abuse
• Use of any prescription or over the counter medication that can affect metabolism
• Excessive intake of alcohol (>7 drinks/week)
• Excessive intake of caffeine (>300 mg/day)
• High level of physical activity (>10 hours/week)
• Lack of desire or willingness to take part in and follow study protocol