Depends on your contract. When I worked at a Kroger in the Dallas area, you were on the clock for 8 hours, and were entitled to one 10 minute break, and 30 minute lunch. You didn't clock out for any of them.
Out here in Portland at FredMeyer our contract says 10 minute break, then if you work beyond 6 hours you are entitled to 1 hour for lunch, and another 10 minute break. You clock out for the lunch. Lots of us tend to skip the final break, and instead take mabye 15-20 minutes for a morning break, and only do half hour for lunch, and leave half hour early. They dont care as long as it doesnt make overtime. I can't imagine why anyone would want an hour lunch, what are you going to do take a nap?
7 or less hrs you get one 15 min.break 8 hrs you get either one 30 min or two 15min. Lunches are optional and you have to ake them up at the end of your shift.