So this book, which has a ship on its cover if I recall correctly, begins with a boy who could use a sort of magic that was uncommon but not exactly rare wherein you could see energy flow and manipulate it with the right discipline, moving objects and X ray vision and the like. So this boy reveals his power to his mother who immediately rejects it and so he stops using it for years and years until some royal fiasco involving power stones with really weird names (blood stone, snow stone, typical fantasy elements) and assorted perks forces a wizard to visit him and curse him with decreased metabolism. that is, he would keep getting hungrier and fatter until he learned enough magic to break the curse, because he is the reluctant protagonist and whatnot. Spoiler alert, he eventually breaks the curse by learning to shapeshift into a seal creature (because apparently the curse only applies to his human body?)...although it really doesnt have much to do with the main plot. His name was Earl Jhord or something like that and the name of the book starts with 'S' like Saskrillion or something. The author had a strange taste in names.
I don't know if that's enough information for anyone to help me but I read it back in 2007 or so. Hopefully it rings a bell and someone can point me to it, I enjoyed it the first time I read it and it would be nice to locate another copy.