Effects of a Non-nutritive Sweetener Reduction Intervention in Pregnancy and Lactation on Maternal and Infant Outcomes

Inclusion Criteria:

• Pregnant

• ≤ 16 weeks' gestation

• Singleton pregnancy

• Report frequent NNS beverage consumption (≥ 7 servings/week)

• 18-45 years of age

• Able to read English at a 5th grade level; and

• Intend to breastfeed for at least the first 6 months of life.

• For infants: The mother must be enrolled and provide assent for the infant toparticipate.

Exclusion Criteria:

• Physical or mental concerns preventing study participation;

• Medication (e.g., metformin; GLP-1 agomists) use that may affect body weight, bodycomposition, insulin resistance, or lipid profiles;

• Tobacco or drug use during pregnancy;

• Alcohol consumption (>1 drink per week) during pregnancy;

• Pre-existing gastrointestinal, inflammatory, or malabsorptive disorders (e.g., -Crohn's disease, ulcerative colitis, inflammatory bowel disease) that may impactNNS absorption or gut microbiota;

• Known suspected/confirmed genetic fetal abnormalities or suspected or knowncongenital birth defects.