The human body gets its required energy from the food it consumes through a process called metabolism. Metabolism is the complete set of chemical reactions that occur in living cells. It is a vital process for all life forms - not just humans. A living thing dies if metabolism stops. With metabolism, cells grow and reproduce, maintain their structures, and respond to their environments.
Resting Metabolism Rate (RMR), which is the number of calories spent to keep you alive, differs from person to person and is normally determined by genetics. Your metabolism is also determined by the amount of muscles you have. One pound of muscle burns 35 to 50 calories a day, while one pound of fat burns only five to 10.
Check your metabolism rate with the Metabolism Calculator
 How Metabolism Works
After the intake of food, enzymes, which are molecules in the digestive system, start the following process:
- Proteins are broken down into amino acids and fats are broken down into fatty acids.
- Carbohydrates are broken down into simple sugars (e.g., glucose). The body also uses amino acids and fatty acids as energy sources when needed.
- These compounds are absorbed into the blood, which transports them to the cells.
- After the simple sugars, amino acids and fatty acids enter the cells, other enzymes act to speed up or regulate the chemical reactions involved with "metabolizing" these compounds.
- During these processes, the body can release the energy from these compounds for use, or store them in body tissues, especially the liver, muscles, and body fat.
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 Balancing Act
The process of metabolism is in reality a balancing act involving two kinds of activities that go on simultaneously:
- Anabolism or constructive metabolism, helps new cell growth, maintains body tissues, and stores energy for use in the future. During anabolism, small molecules get converted into larger, more complex molecules of carbohydrate, protein and fat.
- Catabolism, or destructive metabolism, produces the requisite energy for all activities in the cells. The process involves breaking down the large molecules (mostly carbohydrates and fats) to release energy which heats the body and enables the muscles to contract and the body to move. With the breaking down of the complex chemical units into more simple substances, the waste products released in the process of catabolism are removed from the body through the skin, kidneys, lungs, and intestines.
The metabolism of an organism determines the substances which are beneficial or not beneficial to the system. The speed of metabolism, the metabolic rate, also influences how much food an organism will require.
 How to Increase Metabolism
By adding muscles to your body. Apart from daily exercise, try to find ways which keep you active throughout the day. Above all, eat a healthy diet.
Refer 10 Diet Don'ts That Do Us In
- Never skip breakfast because you haven't had food in 18+ hours. Food, especially complex carbohydrates, fuels your metabolism.
- Eat earlier in the day. Have a substantial breakfast and lunch, and a light dinner, Preferably taken four hours before bedtime.
- Eat a minimum of 1200 calories per day.
- Eating frequent snacks comprising carbohydrates (fruits, vegetables, and grains) fuels your metabolism.
- Eat more carbohydrates (food from plants), and less fat (food from many animals and other food with added fat)
- Daily aerobic exercise is essential (walking, jogging, swimming, stationary cycling, aerobic dancing, etc.)
- A brisk 10 to 15 minute walk at lunch or in the evening will boost your metabolism even more.
- Undertake weight training three days a week.
- Avoid alcohol as it depresses your metabolism and stimulates your appetite.
- Drink 60+ ounces of water a day.
Take this iVillage Quiz Are You Maximizing Your Metabolism? and get expert opinion based on your answers.
 Common Questions on Metabolism
- How can I increase my metabolism?
Exercise regularly and avoid dieting. Your metabolism is determined by gender, age, amount of muscle you have compared to body fat and the amount of exercise you do on a regular basis. Men have higher rates than women because of testosterone. Infants and growing children or teenagers have higher metabolic rates than adults because of growth hormones.
Exercise to maintain or increase muscles helps increase metabolic rate up to 15 hours after exercise. So do an exercise you like for 30 minutes, 5 times a week.
- What are the effects of dieting on metabolism?
While lowering your calorie and fat intake may be important parts of weight loss, both decrease your metabolism. It is, therefore, essential to stimulate the metabolic rate through other means such as routine physical activity. It is not a good idea to skip meals or to reduce calories by an extreme amount, since decreased metabolism causes the body to burn fewer calories and less fat. It may also cause your body to store excess fat in reserve.
- How do I know if I have slow metabolism?
A low metabolic rate is indicated by fatigue, feeling cold, a dry skin, constipation, a slow pulse and low blood pressure.
- Is there any way to lower metabolism?
Metabolism slows down if you eat a very low-calorie diet. Your body thinks it is starving.
- Does genetics play a role in metabolism?
Yes it does. Everyone has a different bone structure and body type. However, given your body type and genetic make-up, you can exercise (with weights and aerobically) to look the best that you can.
- What are the effects of smoking?
Nicotine tends to increase the metabolic rate, which is one of the reasons some people gain weight when they quit smoking. Quitting smoking is best for you, so look for other ways to increase your metabolism.
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