Glen "Big Baby" Davis' pursuit of his dream body in prison might be a little tougher than he imagined ... 'cause TMZ Sports has obtained the menus from his first couple weeks in the slammer -- and they featured a whole lot of carbs.
Davis entered into FPC Duluth in Minnesota back in October ... after he was sentenced to 40 months behind bars for his role in a scheme that defrauded the NBA's Players' Health and Benefit Welfare Plan.
Just a few months before he began his sentence, he told us he was going to use his time in isolation to get jacked ... but check out the options for some of his first meals in the pen -- some weren't exactly the most bodybuilder-friendly.
His first week's dinner choices included pizza, alfredo, lasagna and tacos. His second was a little more healthy, with turkey, steak and roast beef variants on the list.
There were, of course, other nutritious dishes earlier in the day Davis could fuel his workouts with ... fruit, oatmeal and protein-laced sandwiches were staples on the breakfast and lunch catalog.
It's unclear if Davis has already gotten to work on chiseling his frame -- but given the way he stayed positive about the sentence even in the hours leading up to his check-in, it seems likely he's remaining optimistic about his future nonetheless.