Where do you play at? I'm 18 in live in Pennsylvania, but I recently went to Turning Stone Casino in Oneida NY. Played the 1-2 no limit, 100 max. Very easy game to beat, left up around 300.
Chicken wings, cheesburgers, tacos, burritos, spaghetti, pizza, french fries, ice cream, basically all the bad stuff. I only eat one bad meal per weak now though.
Lifting is important if you want to lose bodyfat. Losing weight is easy, losing bodyfat is harder. If you don't eat hardly anything, and just run a lot, you'll be skinny/fat. Basically you'll weigh less but won't be defined.
Work your abs like every other muscle, 2-3 times a week with sets of 20-30. Doing 50,000 situps won't help you if you have high bodyfat. Eat 5-6 small meals a day filled with protein and low GI carbs, such as oats, brown rice, and yams. Running in the morning on an empty stomach is optimal for fat loss.