Which factor contributes to intolerance when using concentrated formulas?

• A. Higher osmotic load
• B. Higher protein content
• C. Greater palatability
• D. Lower viscosity

Answer: (A)

The factor being tested is osmotic load. Concentrated formulas contain more solutes (glucose, electrolytes, amino acids) per unit volume, increasing their osmolarity. When such a high-osmolarity formula enters the GI tract, water is drawn into the lumen to balance the osmotic gradient, which can lead to diarrhea, cramping, nausea, and overall intolerance. Palatability isn’t a driver of intolerance for tube feeding, and higher protein content or viscosity don’t directly cause the osmotic-related intolerance seen with concentrated formulas. Lower viscosity would mainly affect administration ease, not the osmotic effect.