--often due to the twin mechanisms of fluid retention and carbohydrate craving, is a fairly common and well-documented side effect of Gabapentin.

This effect is common with many of the anti-epileptic medications, with the interesting exception of Topomax, which is more often associated with weight loss.

The common side effects are listed in the insert given with Gabapentin/Neurontin prescriptions:

http://www.accessdata.fda.gov/drugsa...129s027lbl.pdf