What is a common cause of failure to thrive in infancy?

• A. Inadequate caloric intake or malabsorption; underlying medical problems
• B. Overfeeding
• C. Excess activity
• D. Genetic mutations only

Answer: (A)

In infancy, failure to thrive most often comes from not getting enough calories or from problems that prevent nutrients from being absorbed. Infants depend on adequate intake to fuel rapid growth, so when feeding is inadequate—due to difficulties with feeding, improper formula preparation, or illness reducing appetite—weight gain slows and growth falters. Malabsorption from gastrointestinal or metabolic issues can also lead to poor nutrient uptake even if intake seems adequate. Other scenarios, like overfeeding or excessive activity, don’t typically cause FTT; genetic mutations can contribute but are less commonly the sole cause in typical cases. So the best answer points to inadequate caloric intake or malabsorption, with possible underlying medical problems contributing to the growth issue.