text: how would you gain weight if you are naturally born skinny? what exercise would fit you to gain weight?   i had the same problem, i'd always eat like a horse (no, not hay and oats - just massive amounts) and never put on weight. then i found i have a gluten intolerance. (gluten is a component of wheat, rye, barly and oats). i am now on a gluten free diet and my weight has gone from 61kg to 75kg. i dont have to run arround under the shower to get wet.  try a gluten free diet. may work.