What diet is best for me, if im trying to get six pack ?

Im 5'7 151 lbs. I just got the bottom to work on. My diet now is watch what I eat. Im not big on reading the labels, but I did eat chicken mostly for dinner with some veggies and salad. (i did avoid carbs during dinnner tho )My Breakfast was a bowl of special K cereal, or eggs, lunch also some chicken. But i did eat out like once a week and usually didnt mind of eating candy or grabbing a burger. I have for the last three days switched to the low carb which uses fat as fuel instead of carbs but i dont want to gain weight back if i happen to eat out or stuff like that cuz i do like somethings and dont want to cut them out. Should I just keep working out and watch what i eat or do the low carb diet(atkins kind of diet but not extreme) I work out 6 days