Assume the smoothies have the same nutrient profile as a regular diet. Like if you drank runny mashed potatoes and protein powder to simulate a normal food intake.
If you do poop because of the nutrients, is there a healthy diet at which waste products are no longer left in the intestine to turn into poop?
Drag has no intention of doing this, drag is just curious about the science.
I think breast milk might hold the secret to the answer here. When our baby was newborn and breastfeeding, she was healthy and strong and everything, but BARELY ate enough to sustain and grow. She would go 5+ days without pooping with no signs of constipation. The doctor told us “don’t worry about it. Breast milk has all she needs. Nothing more, nothing less”.