Fat but fit: Can I still be healthy?

You can be overweight and still be relatively fit. But it depends if the extra weight you carry is muscle or fat. If the extra pounds are muscle, your risk of disease is lower than if this weight was fat. If your extra weight is fat, you are at increased risk of diabetes, cancer and stroke — even if you exercise.

However, this doesn’t mean you’re not benefiting from exercise if you’re overweight or obese. You are. Regular exercise can help reduce the risk of certain diseases. However, your weight is also important to your health. For example, if you’re overweight or obese, you can reduce your risk of heart disease if you exercise — but you’re still at increased risk of diabetes if you don’t lose weight. Also, carrying extra pounds into your 40s and 50s may put you at increased risk of developing diabetes and heart disease later in life — even if you have no other risk factors for these diseases.

Regular physical activity is an essential component to maintaining muscle and a healthy weight. Health experts recommend at least 30 to 60 minutes of moderate-intensity activity five or more days a week. To lose weight, increase the duration and intensity of your exercise, eat a healthy diet and cut back on your portions.

source: http://www.mayoclinic.com/health/weight-loss/AN01033