When I started hiking every week, I dropped 10 lbs in 6 months.

When I stopped drinking soda every day I dropped nearly 10 more.

Eat better food - real food. Eat every day. Have something for breakfast. Get moderate exercise. Get a physical to make sure you are not hypo/hyperthyroid, or any other medical issue that can radically influence weight.

I can and do eat junk food, when I am backpacking and in a calorie deficit. Unless something happens to upset my system - stomach flu last October radically screwed up things and I lost too much weight! - my weight remains consistent. It takes time to find your balance. Write everything down each meal and be more aware of caloric intake, and balance it to your level of activity.

I don't do much exercising during the week, tho I have taken to parking farther from stores so that I am walking more. But I started with a baseline - I know that I have no medical condition that complicates my metabolic performance. And I have over time become much more aware of my body's needs much quicker. Staying hydrated at home as well as on the trail is important. Getting enough sleep is also important - there was a study that linked sleep deprivation to weight gain, not so long ago.