I limit my food intake to two thousand calories, try to eat as healthy as possible and exercise three to five days a week. however, i can not get below 160 pounds at 56. how, can i change my lifestyle to lose the extra weight?

You need to reduce your food intake to no more than 1200 calories. This will have to be a long term change otherwise you will lose weight and gain it back up as soon as you slacken on your food intake. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs.