In the answer to "How do you feed a starving person in a way that won't kill them?", it is mentioned that refeeding syndrome can cause peripheral edema. How does this occur?
During refeeding syndrome (RFS), intake of carbohydrates causes a massive surge in insulin levels, leading to electrolyte abnormalities. Increased insulin also caused sodium and water retention independent to changes of renal GFR and RPF . Water retention increases capillary hydrostatic pressure, leading to peripheral edema.
Another possible contributor to peripheral edema during RFS is hypoalbuminemia, which decreases capillary oncotic pressure .