Wanted to post a link to a reply I just made in another thread where I show photos of myself and my husband, both solidly pooh-sized, on some rides (7DMT, Space Mountain, Test Track, EE).  I'm 5'8", 300-ish lbs.  He's the same height, weighed around 350-360 in these photos.  Sometimes seeing the photos is helpful for folks who may otherwise be having some anxiety or doubts about whether they can participate!  
5'1" 375 worried momma
I relied heavily on the comments here for the encouragement I needed to have a good time in WDW for my last few trips!  Wanted to pay it forward