I need a flat stomach!!!!

Please help I am 5'6 weigh 170 pounds. I am 52 years old and do metabolic training 3 times a week and Zumba 3 times a week I can maintain my weight but can not lose weight or get my stomach flat. I keep my caloric intake to 1500 calories daily and wear a size 10 please advise or make suggestions. Thanks.

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