Studying Phenotypic Risks for Obesity and Underlying Traits in Young Infants

Studying Phenotypic Risks for Obesity and Underlying Traits in Young Infants: A Pilot Study

The purpose of this research study is to understand how infants metabolize different meals and to develop clinical tools which identify infants as having two different phenotypes. The phenotypes are the 1) metabolic "thriftiness" and 2) the metabolic flexibility.

The purpose of this research study is to understand how infants metabolize different meals and to develop clinical tools which identify infants as having two different phenotypes. This will be accomplished by providing two meal test stimuli to infant participants (human milk and infant formula). Energy expenditure and respiratory exchange ratio will be obtained before and after the meals to calculate the delta in both. From there, two phenotypes will be identified. The first phenotypes is metabolic "thriftiness", which will be defined by the energy expenditure after consuming two standard meals. The second phenotype is the degree of metabolic flexibility and will be defined by substrate oxidation (using respiratory exchange ratio) following two standard meals.

Inclusion Criteria:

• Aged 2 weeks to less than 17 weeks at screening
• Being fed human milk as a primary source of food
• Be willing to consume one meal of infant formula
• Be willing to complete a DXA measurement

Exclusion Criteria:

• Unable to complete the screening visit and two clinic visits within 14 days
• Born with health conditions that would render procedures unsafe
• Born earlier than 35 days and 0 weeks gestation
• Eating supplemental foods
• Physician diagnosed feeding difficulties that may require a special type of nipple for bottle feeding