Re: Lifting weights
If you train incredibly hard, have perfect nutrition, and fantastic genetics, you MIGHT be able to gain enough muscle to look masculine. My point is, it won't happen overnight or by accident.
If you lift weights you should gain some muscle. Muscle will increase your metabolism allowing you to eat more and maintain your weight. However, muscle weighs more than fat, so you could look slimer but actually have increased your mass. That's why scales are useless for determining health.
My advice is to get active and go ahead and enjoy your junk food. Eat healthy 6 days a week and whatever you want on the 7th. Or eat smaller portions of junk each day and get enough exercise to use the extra calories.