Lower Protein Intake and Long-term Risk of Obesity and Cardiovascular Disease

Obesity and its cardiovascular consequences are the most important causes of morbidity and mortality worldwide. Breastfed infants have been shown to have less cardiovascular risk factors in adulthood, which can be partially explained by their slower growth compared to formula fed infants. The primary objective of this study is to investigate if consumption of lower protein formula can slow the rate of weight gain of formula-fed infants between 3 and 12 months of age. Secondary objectives include investigation into whether infant nutrition and growth have an impact on later risk of obesity and atherosclerotic cardiovascular disease (CVD), the critical windows for these programming effects, and the mechanisms of action.

• Modified infant formula (Other): Test formula with lower protein content than standard formula
• Standard infant formula (Other): Standard infant formula

Primary outcomes

• Infant weight gain [Between ages 14 weeks (+/- 1 week) and 12 months (+/- 2 weeks)]: Rate of weight gain (g/d)

Secondary outcomes

• Body mass index (BMI)-for-age Z-score [Age 2 years (+/- 1 month)]: Based on World Health Organization (WHO) growth standards
• Height-for-age Z-score [Age 2 years (+/- 1 month)]: Based on WHO growth standards
• Adiposity [Age 2 years (+/- 1 month)]: Sum of 4 skinfolds (triceps, biceps, sub-scapular, supra-iliac)
• Fat mass [Age 2 years (+/- 1 month)]: Deuterium dilution (assessed in subset)

Other outcomes

• Infant weight gain [Between 6 and 12 months]: Rate of weight gain (g/d)
• Weight [Ages 4, 5, 6, 12 and 24 months]: Body weight (kg)
• Length or height [Ages 4, 5, 6, 12 and 24 months]: Length or height (cm)
• Head circumference [Ages 4, 5, 6, 12 and 24 months]: Head circumference (cm)
• Body mass index [Ages 6, 12 and 24 months]: Weight and length or height will be combined to report BMI in kg/m\^2
• Weight-for-age Z-score [Ages 14 weeks and 4, 5, 6, 12 and 24 months]: Based on WHO growth standards
• Weight-for-length Z-score [Ages 14 weeks and 4, 5, 6, 12 and 24 months]: Based on WHO growth standards
• Height-for-age Z-score [Ages 14 weeks and 4, 5, 6, and 12 months]: Based on WHO growth standards
• BMI-for-age Z-score [Ages 14 weeks and 4, 5, 6, and 12 months]: Based on WHO growth standards
• Adverse events [Ages 14 weeks and 4, 5, 6, 9, 12 and 24 months]: Safety
• Feeding intake [Ages 14 weeks and 4, 5, 6, and 12 months]: Infant feeding questionnaire
• Feeding tolerance [Ages 14 weeks and 4, 5, 6, and 12 months]: GI symptom and stool pattern questionnaire
• Metabolic markers of cardiovascular health [Ages 6 and 12 months]: Blood sample (in a subset)
• Blood pressure [At age 12 and 24 months]: Systolic and diastolic blood pressure (in a subset)
• Appetite and feeding / eating behavior [Ages 14 weeks and 4, 5, 6, and 24 months]: Baby and Children's Eating Behavior Questionnaire

Sex: All, ages: 13 Weeks to 15 Weeks, accepts healthy volunteers

Inclusion Criteria:

* Healthy term infant
* Infant is aged 14 weeks (+/- 1 week)
* Infant is exclusively formula feeding or predominantly breast-feeding at age 14 weeks

Exclusion Criteria:

* Any adverse maternal, fetal or infant medical history that may have effects on growth and/or development
* Infant born with congenital disease or malformation affecting growth and/or development
* Food allergy to any trial products (e.g. milk, soy)

• Results publication: Gonzalez-Garay AG, Serralde-Zuniga AE, Medina Vera I, Velasco Hidalgo L, Alonso Ocana MV. Higher versus lower protein intake in formula-fed term infants. Cochrane Database Syst Rev. 2023 Nov 6;11(11):CD013758. doi: 10.1002/14651858.CD013758.pub2. PMID 37929831

• Atul Singhal, MD, Principal investigator, Childhood Nutrition Research Centre, University College London, Institute of Child Health