The Bottle Optimization Testing Tiny Little Eaters Study

The study will enroll 220 mother-infant dyads.

Inclusion criteria

• Mother-infant dyad: The biological mother is the legal guardian of the infant and has custody for ≥5 days per week (in cases of joint custody).
• Maternal age: Mother is ≥18 years old.
• Language: Mother understands spoken and written English sufficiently to provide informed consent, answer questionnaires and follow study instructions.
• Gestational age: Infant was born at 37.0-42.0 weeks gestation.
• Birthweight: Infant's birthweight was appropriate for gestational age.
• Bottle feeding: Infant currently receives at least one bottle feeding of ≥2 ounces at least once per week.
• Residence: Family lives within approximately one hours driving distance of Ann Arbor, Michigan to participate in an at- home appointment or is willing to drive to the U-M North Campus research site.
• Infant age: Infant is 4.0-6.0 months old at enrollment.

Exclusion criteria

• Current maternal depression or anxiety, as assessed by screening questionnaires, or any cognitive impairment that would limit ability to follow study instructions.
• Infant developmental delay, genetic condition, or medical problems or diagnosis affecting current or future eating, growth, or development.
• History of significant sucking or feeding difficulties or breastfeeding difficulties requiring significant medical intervention or support.
• Current weight-for-age below the 10th percentile or significant history of poor weight gain.
• Infant already typically uses a slower-flow nipple (flow rate < 5 mL/min).