dietician marissa moore says as we age, men and women tend to see a slowdown in their metabolism. >> the primary cause for the slowdown of metabolism is the fact that the body tends to start to replace lean body mass with fat mass. and muscle burns more calories than fat does. >> reporter: and that means it's easier to gain weight. she offers these tips to maintain a healthy metabolism. >> make sure that you are physically active. as much as can you every day. make sure that you do maintain a healthy and balanced diet. stay away from fad diets and products that promise to help rev up the metabolism. they generally don't work. >> reporter: she is accepting this fact of life. >> i just want to be healthy. but end of the day if my definition and of healthy and my feeling my best isn't me in my 20s, that's okay. it's just okay. >> reporter: i'm elizabeth cohen. >>> and are you part of the so-called sandwich generation? if you are caring for your aging parents as well as your teenagers, then you are. some tips on how to get the most care for your money next. [ woman ] the blue bomber. [ m