Hormonal Regulation of Postpartum Weight and Presence of Gut Peptides in Human Milk Studies suggest that childbearing is an important contributor to the development of obesity in many women and that breastfeeding may be protective.

Ghrelin and peptide YY (PYY) are gut hormones involved in appetite regulation and energy homeostasis and are biological neuroendocrine signals that potentially affect body weight and adiposity/

Role of Ghrelin and PYY in Postpartum Body Weight Regulation and Presence in Human Milk.

This study evaluated whether fasting or postprandial ghrelin or PYY is different between lactating and nonlactating postpartum women matched for age, body weight, and adiposity.

Eligibility Criteria: Healthy females, 18+ years old, non-smokers, no major food allergies, first-time mom, currently pregnant or within 1 month of giving birth.

Inclusion Criteria:

• Healthy women (non-smokers) at least 18 years old who did not have any pregnancy complications, and gave birth to their first child within one month.
• The study is open to women who are breastfeeding or formula feeding.

Exclusion Criteria:

• Smoker,
• had twins or triples,
• had any major complication of pregnancy(example,
• gestational diabetes);
• have kidney, liver, hormonal, stomach, intestine,lung, heart or blood disease. This also includes high blood pressure;
• use prescription or over-the-counter medicine or herbal drinks or pills.
• History of depression, anxiety, disordered eating, other psychological problems, alcoholism or other substance abuse.
• Severely claustrophobic.
• Having a strong fear of needles and/or do not feel you can have blood drawn every 30 minutes from a plastic catheter.
• Are not able to or willing to fully participate in the study, and are pregnant, anemic or have a thyroid problem.