Metabolism refers to the way the body burns calories to create energy and maintain life. The digestive system uses a variety of enzymes to break down the nutrients we ingest, converting them to fuel that keeps our bodily processes going and give us the supply of energy we need to function. Each body uses food slightly differently since the metabolism is at least partially influenced by hereditary factors. While some individuals have fast metabolisms and burn calories quickly, and other people have sluggish metabolisms and have a tendency to gain excess weight, individual metabolism can be affected by medical conditions and behavioral changes.

Factors That Influence Metabolism

Several factors influence a person's metabolic rate. In addition to hereditary factors, metabolism is influenced by age and by gender. Metabolism begins to slow in individuals older than 40 years of age, and women, generally speaking, have slower metabolisms than men. A slowing metabolism can be improved if an individual increases activity level and lean body mass. Research has shown that people with increased muscle tone have higher metabolic rates than their less muscled peers.


Although basal metabolism is, to a large degree, inherited, it can definitely be altered by activity level. The more an individual engages in physical activity, the more calories are burned. Aerobic exercise, during which heart rate and breathing rates increase noticeably, is the most efficient way to burn calories. Aerobic exercise may include fast walking, jogging, bicycling and swimming. In addition to being generally more drawn to physical activity, those with higher metabolisms have also been found to be generally more fidgety than others, using more energy even when they are at rest.

Some simple methods of increasing activity level can work well. These may include:

  • Parking at a distance from one's destination
  • Taking the stairs instead of the elevator
  • Engaging in everyday physical activities (cleaning, gardening, car washing)

By elongating periods of physical activity, patients are able to speed up their metabolisms, burn more calories, and, if desired, increase weight loss. Thirty minutes of daily exercise is recommended. Even if individuals break these activity periods into small chunks, exercising for 10 to 15 minutes at a time, they can reap benefits in terms of speeding up their metabolism. Strength-training exercises, such as weight-lifting, are also important because they help prevent the muscle loss that normally occurs during aging. Since muscle tissue burns a greater number of calories that fat tissue, building muscle mass results in greater weight loss.


Dietary changes can also help to increase metabolism. These may include:

  • Drinking plenty of water
  • Eating a diet rich in lowfat protein
  • Eating small meals and snacks frequently
  • Avoiding crash diets
  • Eating plenty of fruits and vegetables
Coffee, green tea, and energy drinks containing taurine (an amino acid), are known to accelerate metabolism, but these should be ingested in moderation and not by children or teenagers. Spices, for those who can tolerate them, are also known to increase metabolic rate.

The simple formula for increasing weight loss is to take in fewer calories than you expend in activity.

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