Metabolism describes the ongoing chemical reactions in the body, such as the breakdown of food and its transformation into energy. This is controlled by hormones, which secrete enzymes to achieve this task. These chemical messengers, secreted by the glands of the endocrine and the nervous system, control your body's metabolism. Your metabolism can be upset by a variety of events, including genetic disorders and hormonal problems.
Metabolic typing is based on the belief that each person has a unique metabolism, and that diets should be tailored to reflect these differences. Balancing your body chemistry can result in a significant increase in energy production. One can therefore recommend a particular diet to bring the body into balance and harmony.
At rest your body burns an amount of calories per day to maintain basic functions such as breathing and circulating blood. One pound contains 3500 calories. This means losing a single pound requires 3500 more calories to be expended than your actual calorie intake. A healthy rate of expenditure occurs when someone exercises regularly at moderate levels of exertion, which will burn approximately 300 to 500 extra calories per day depending on height, weight and physical activity level. Metabolic rates vary from person to person; men generally have a higher metabolic rate than women.
Your metabolism slows down as you age unless you keep a healthy lifestyle with regular exercise and avoid caloric excesses. One of the reasons for this is to conserve and protect bodily tissues and internal organs as well as energy.
Studies have shown that there is a correlation between healthy levels of physical activity, proper nutrition and higher metabolic rates. Therefore, it's important to keep your metabolism at an optimum level through diet and exercise if you want to stay as healthy as possible as you age.
The body has three main sources of energy
- Carbohydrates are sugar compounds found in foods such as bread, cereal, potatoes, and fruits. These are broken down into glucose after digestion and stored in the liver and muscles.
- Lipids are fats (such as cholesterol) stored as body fat, which are broken down into fatty acids for energy.
- Proteins comprise nearly three quarters of all solid material in the body, and are therefore crucial structural components. They are made up of amino acids, which are the building blocks of proteins. Protein is present in the diet in foods such as meat, eggs, nuts and dairy products.
Basal metabolic rate (BMR) is the amount of energy burned at rest and contributes 50-80 percent of energy used by the body.
Source: TanitaRose.com
How do you measure your metabolism?
It is not easy to calculate how fast your body burns calories, but a good estimate can be made with the help of a formula based on your height, weight and activity level. To calculate yours accurately take these steps:
- Take a tape measure and place it around the largest part of your waist to measure the circumference of your waist in inches.
- Convert your height in inches to feet and inches.
- Multiply your weight in pounds by 0.4515, then multiply your height in inches by itself.
- Multiply that number by your weight, then divide this new number by 220 to get the approximate number of calories you burn per day.
This formula is meant as a rough estimate, but can be greatly changed based on various factors such as the following:
- Body size - larger people have a larger BMR
- Age - metabolism slows with age, due to a loss in muscle tissue but also due to hormonal changes
- Youth - infants and children have a higher energy demand per unit of body weight due to the demands of growth
- Gender - men tend to have faster metabolisms than women, as they are generally larger with less body fat
- Genetics - your metabolic rate may be partly decided by your genetic composition
- Muscle tissue – more muscle tissue will burn more energy
- Body fat - fat cells burns less energy than muscle tissue
- Hormones - hormonal imbalances can influence how quickly or slowly the body burns energy
- Illness - BMR will increase because the body has to work harder to fight the infection
- Exercise - exercise increases muscle mass and the body gets used to burning energy at a faster rate
- Drugs - caffeine or nicotine can increase the BMR
What are the dangers of a slow metabolism?
A slow or sluggish metabolism can lead to weight gain, which is an indicator of metabolic syndrome. It consists of five clustered conditions, including a large waist and high blood glucose levels, which increase the risk of heart disease, high blood pressure, diabetes, cardiovascular disease as well as mental health issues such as depression.
One study found that women who lose weight can see their risk of breast cancer increase; this is because the body's estrogen levels decrease, which may lead to a proliferation of ER+ (estrogen receptor positive) tumors. Estrogen is linked to cell division and growth and is associated with slower tumour progression and increased survival rate in breast cancer patients.
Other potential health risks linked to a slow metabolism include:
- Skin disorders
- Reduced fertility or pregnancy complications
- Chronic fatigue syndrome
- Delayed wound healing
- Osteoporosis
- Fractures
- Arthritis
- Gum disease (which increases your risk for tooth loss)
- Difficulty burning fat stores
Tips for boosting your metabolism
You might be trying to lose weight, trying to counter the effects of ageing on your metabolism or simply trying to feel better. Here are some tips which will help you optimise your metabolism:
- Exercise – this will help you boost your metabolism by ensuring you burn fat and build muscle tissue. This may be weight training, jogging, walking, swimming or cycling - at least three times a week.
- Diet – make sure you are getting enough calories in your diet, otherwise you may be inadvertently slowing your metabolism. Smaller, regular meals work best for your metabolism, with breakfast especially crucial. Eliminating or minimising sugar intake from your diet will prevent converting and storing this as fat. Consume complex carbohydrates, such as whole grain cereals, as these are low glycemic foods that are broken down gradually and will help maintain an even blood-sugar level too. However, reduce your carbohydrate intake after 6pm.
- Limit your intake of caffeine and stay well hydrated with plenty of water intake.
- Stress – avoid or minimise stress as it causes weight gain, by activating the release of cortisol, a steroid that slows metabolism.
- Sleep – get at least 7-8 hours sleep a night, so your body has a chance to recuperate.
If you are interested in boosting your metabolism see a personal trainer or dietitian soon.
Originally published on Apr 28, 2009
