I find that too much of anything is a bad thing when it comes to candida… rice has starches, even though its brown rice too much cant be good. The best way to gain weight is to focus on getting your candida better.
If you are able to exercise that might help you gain weight by eating that much rice, but i find that weight lifting is very hard on the adrenal glands when you have candida.. but maybe i just have weak adrenals. I found i was able to put on weight, but i couldnt keep it on without making my candida worse. http://www.bodybuilding.com has some good workouts.