Can a Skinny person eat McDonald's to gain weight?

Update: I know it is unhealthy, and there are other choices out there... but first let me say.. I am 20, and 5'9 @ only 102lbs See my problem? I am trying to get to 140lbs, while working out just pecs and abs. I'll be eating McDonalds 2-3 times a day along with plenty whole foods... other than health issues,... show more I know it is unhealthy, and there are other choices out there... but first let me say.. I am 20, and 5'9 @ only 102lbs

See my problem? I am trying to get to 140lbs, while working out just pecs and abs.

I'll be eating McDonalds 2-3 times a day along with plenty whole foods... other than health issues, would the McDonalds cause any issues with muscle mass/tone?
21 answers 21