I noticed I’ve gained some weight around my stomach area and it really upsets me. What are some ways to lose the weight quickly without a strict diet? Any good exercises?

About 2 years ago I went from 165 to 195 and my 34" waist disappered. I went on a diet consisting of 3 meals a day and only water, while doing crunches every morning and in just a couple of months I was down to 175 and my waist was back to normal. My waist and body still look the same, but I have now reached back to 185 and my belly fat just won’t go away no matter what I do. I have always wanted abs and being 6’2 and 185, I am by no means overweight yet the only fat I have is my stomach. How do I burn that fat easiest and quickest? I am on the go a lot with college so I don’t have a lot of time to focus on a strict diet or intense weight training.