<human>: When I was around 18, I was not a very fit guy. While not necessarily overweight, I had some fat, didn't build any muscle mass so I just didn't have a defined shape. At 5'8 I was around 160. Once I met my girlfriend, I decided to put myself into shape. 

I ran, worked out and lost 20 pounds. Now I'm 5'8, at 140ish. I'm not bulky in muscle, but I'm certainly defined and no longer have a stomach. I feel my face is thinner and I feel great.

However a month ago something changed. I've never really ate much since I started working out. But I just started not eating. Like I would go from morning till night eating nothing but a Pop Tart. 

This went on for a few weeks, and I never thought it was a problem until I realized, that isn't healthy. So I started eating again. Not even fattening foods, just normal meats, cheese, dairy and wheats. Low fat foods. 

However just from eating, I feel bloated and fat. I look at myself now and I think I gain weight so I work out more. But just from eating I feel bad. 

This isn't normal for a guy, and I want to know what the hell to do. Help.

Give me the gist of the text in a nutshell
<bot>: Used to be chubby-ish. Worked out. Started just not eating out of habit. Forced myself to eat and now I feel terrible. Help.