Originally Posted by TheFlyingDutchman
... To wit: Ever seen starving children in Africa? Their stomachs are bloated, yet they are starving. The reason for this is that their blood has an a very low osmolarity (low concentration of particles) since they aren't eating. However, their tissues have high osmolarity compared to their blood. Since water travels in and out of cells infinitely more easily than proteins, water is drawn into the tissues to lower the osmolarity of the cells and raise osmolarity of the blood, thereby balancing the difference in osmotic pressure. This water retention causes the bloating you see.
Just to clarify, I don't believe the water goes into the tissues. I believe it goes into for example the peritoneal cavity, which is different -
It's not that they aren't eating - many of these children eat ample meals a day. The issue is they aren't eating any protein
; they're eating only starches. The protein is critical for maintaining the colloid osmotic pressure.