Current research shows that dairy protein accelerates infant weight gain, which is a risk factor for later on obesity and metabolic syndrome. However, dietary protein from other sources haven't been studied yet. This longitudinal study will compare two complementary feeding regimens with dietary protein mainly from 1) meat; 2) dairy on infant growth, body composition and gut microbiome from 5 to 12 months of age in formula fed infants. Healthy infants at approximately 5 months of age will be randomized to either a meat protein, or a dairy protein group with complementary protein mainly from meat or dairy. Infants will consume one of these diets for 7 months (6-12 months of age) and infant growth, body composition, growth biomarkers and gut microbiome will be measured to compare between groups and over time.

Two observational follow-up visits will be conducted at 18 and 24 months of age.

Inclusion Criteria:

• 1-5 months of age
• Formula fed
• On breast milk less than 1 month
• Healthy
• Term Birth (36-42 weeks)
• Appropriate for gestational age

Exclusion Criteria:

• Congenital anomalies that impact feeding, growth, or development
• Low birth weight
• Not able to consume milk-based formula
• Known chronic diseases or allergies affecting protein consumption/digestion