Many readers are struggling with the same issues, and I frequently get asked similar versions of the same questions.The following question is from one of our readers, and I thought the response might be helpful to many of you.Q: I would love some advice on workouts and diet. I am 50 and, yep, that metabolism is starting to slow down. I am trying to do my 1250 calories and I keep track on my iPhone, but the scale stays exactly the same. I usually do my elliptical for 30 minutes a few times a week and/or a 30 minute walk. No gym membership at this time.Does this sound familiar to you? I get this question a lot from people in their 40s or older, when their metabolism starts naturally slowing down.QUIZ: Are You Getting the Right Nutrients?The reader has it right: Metabolism, metabolism, metabolism. In my last article, I outlined a simple plan to maintain metabolism and lose weight. Based on the information in that article, along with a few new specifics, here is my breakdown of the issue and my advice:Concern #1: Your calorie intake is too low.  If you truly are only consuming 1250 calories a day, you’ve got to consider the likelihood that you are losing calorie-burning lean tissue, such as muscle, especially given the fact that strength training isn’t currently part of your routine. A decrease in muscle mass brings with it a decreased metabolism. The unchanging scale, or weight loss plateau, tells you that you are now eating as many calories as you are burning. Given that fact, your typical options for additional weight loss would be to decrease calories further, or increase the number of calories you burn through exercise or the thermic effect of food. In your case, you do not want to cut your calorie intake more than you already have. It is already low, and maybe too low to promote a high metabolism. Gradually, we want to bring your calorie consumption back up a bit. But not right away.  For now, try a trick that has mainly anecdotal rather than empirical evidence of effectiveness. It’s called calorie cycling, and the goal is to get your metabolism off of steady-state calorie-sparing mode.COLUMN: The Deal on Calorie-Counting, by Dr. Oz & Dr. RoizenWith calorie cycling, you maintain the current weekly calorie consumption but vary the consumption from day to day. So instead of eating your 1250 calories every day, you might eat 1000 one day and 1500 the next, or even 900 one day and 1600 the next. Try this approach for a month or two, along with the other suggestions in this column. If you have successfully broken through your weight loss plateau, it will be time to increase your calorie intake by just 50 calories or so per day. This is assuming that you don’t want to be stuck with a 1250 calorie per day diet for the rest of your life.Concern #2: Your cardio workout is predictable.Your body becomes very efficient at what it does often and routinely. That means you burn fewer calories than you used to with the same activity. Throwing your body a surprise curve ball will charge it up to burn more calories.Switch up your cardio routine in at least one of the following ways, and preferably with more than one.1)     Vary the intensity of your workouts. On some days, keep your pace consistent for the entire duration of the workout. On other days, add more intense intervals by increasing the pace of your walk (even adding a little jogging if you can) or by increasing the rpms, the resistance, or the incline on your elliptical. You’ve got to throw some intensity in there—as much as you can tolerate without hating it or injuring yourself. Start modestly, with just 30-second to one-minute high intensity intervals. Then gradually increase the duration of those intervals.2)     Vary the duration of your workouts. Two or three days per week, increase the time of your cardio to 45 minutes. On another day, ramp up the intensity of the entire workout, but decrease the duration to 20 minutes.3)     Increase the frequency of your workouts. If you are working out three to four times per week, add another one or two days.4)     Vary the activities. If possible, add another activity or two to your cardio workouts. This doesn’t have to be cycling or swimming or attending a class. It can be as simple as running the stairs in your house or jumping rope for short bouts. Throw them in to your workouts.QUIZ: What’s Your Fitness Level?Concern #3: You are not building muscle.With your current routine, you are likely losing muscle mass. You want to maintain and preferably increase your lean body tissue. This will combat the decrease in metabolism that often accompanies both dieting and aging. You’ve got to begin some resistance training.Get yourself some dumbbells and use them, along with body-weight exercises such as squats and lunges, for 15-20 minutes, three times per week, not on consecutive days. To begin, you’ll need dumbbells that range from 5 to 10 pounds. Within two months or so, as you get stronger, you should be purchasing weights up to 15 or 20 pounds. Start with a basic, beginner weight training routine. You can get fancy if you want later on.I hope this helps. As you approach weight loss, don’t sabotage yourself by using techniques that lead to a slower metabolism (other than the slowing that comes from simply having a smaller body). Those would include dramatic calorie reduction and the absence of strength training from your workout routine. Keep your muscle mass up, keep your activity level up, keep your body guessing and adapting, and cut your calorie intake only modestly.WATCH VIDEO:MORE: Weight Loss Myth: The Dreaded Plateau