Jared Fogle is a lot of things ... but one thing he's not is fat.
Fogle has reportedly been on a downward dietary spiral at Englewood prison in Colorado ... supposedly heavier by 30 lbs and counting, courtesy of the prison commissary.
Fogle's attorney, Ronald Elberger, tells us it's all a lie ... his client hasn't gained a pound in prison ... to the contrary he exercises regularly on the prison track.
He's eating standard prison fare, including soups, burgers, beef stew, BBQ chicken and enchilada casserole. There are reports he's scarfing down Honey Buns ... Elberger says not true.
The lawyer says Fogle is actually doing quite well in the first few months of his 15 year sentence.