If you eat a lot of salt, you might hold more water than necessary.
But it is normal to gain a few pound back after fasting. You are refilling your digestive system. The general rule of gaining is 5-8 lbs after the fast. Although, if you have a lot to loose and eat a very light diet with good fats after fasting, you should keep loosing slowly.
A healthy body lets go of weight, water and fat, easily, so focus on getting healthy. Healing the glands, liver, colon ... Most importanty to loose the weight is excellent digestion, like going more than twice a day and eliminating well. And for that of course a very healthy high fiber diet. Sugar
is a no, no and even honey and fruit can make some people puffy. Oh, another idea, is, you know how inflamed skin keeps oozing water. When the body is inflamed, it will hold water and look puffy. Like a person with an eating disorder, everything from bulimia to plain overeating, is often inflamed and therefore puffy. But I don't want to scare you, maybe it's just the salt.
hope this helps,