People often say that a slim person's metabolism “must be fast” because they are able to burn calories faster; and that an overweight person's metabolism “must be slow” because they burn calories slower. This is not necessarily the case.
Three factors determine your weight: metabolism, diet, and exercise. Though largely genetically determined, your metabolism is directly impacted by the combination of your diet and physical activity. Therefore, we can say that diet and exercise are what ultimately determine your weight (unless you suffer from a medical condition, such as hypothyroid). And so, understanding your weight is a question of simple mathematics: if you eat more calories than you burn, you will gain weight. If you burn more calories than you eat, you will lose weight.
Your body needs energy (calories) for 3 reasons:
- Basic needs. Even when your body is at rest, it requires energy for the basics, such as fuel for organs, breathing, circulating blood, adjusting hormone levels, growing and repairing cells. The rate at which you burn calories for these functions is called your basal metabolic rate (BMR). About 3/4 of the calories you consume are used for this.
- Food processing. Your body uses about 1/10 of the calories you consume to digest, absorb, transport and store what you eat.
- Physical activity. The rest of the calories you consume are burned via physical activity.
Apart from physical activity, other factors affect how many calories your body will burn:
- Body size and composition. The larger you are, the more calories your body will burn. Muscle burns more calories than fat does, therefore if you are lean, you will burn more calories.
- Age. Older people tend to have less muscle and more fat. Metabolism also slows naturally with age. Together this means that the elderly burn fewer calories.
- Sex. Men usually have less body fat and more muscle than women of the same age and weight. This is why men generally burn more calories than women, and why they can generally eat more without gaining weight.
- Genetics. You were born with an approximate basal metabolic rate (BMR) that will, unless you make certain lifestyle choices, maintain itself.
Consciously, you can only alter your metabolism via diet and exercise. This is because diet and exercise alter your body composition, and therefore the rate at which you burn calories.
To boost your metabolism, follow these simple steps:
· Practice moderate aerobic/cardiovascular activity 3-5 times a week. This causes your body to use its fat (stored energy) for fuel, and prevent further fat accumulation.
· Seek to build muscle mass, because muscle burns more calories than fat. You can do this by lifting weights and consuming more protein (carbohydrates and fat are not muscle-builders).
· Eat foods with less fat and more nutrients: lean meats, whole grains, low-fat dairy, fresh fruits and vegetables.
· Eat 5-6 times a day, in small portions. This prevents your body from storing excess calories as fat. Do not skip meals as this trains your body to store whatever it is that you do eat, when you finally do.
· Avoid stimulants like coffee, tea and cigarettes which alter your appetite.
· Avoid processed/packaged foods that have hidden calories and chemicals. A good rule is to “avoid foods your grandmother wouldn’t recognize”, in other words try to eat food in its most basic form.
· Do not use dietary supplements that claim to “speed up your metabolism”. They may produce undesirable or even dangerous side effects such as heart failure or weight gain later in life – manufacturers do not have to prove that their products are safe or effective.
Nature has the best recipe for success: Celebrate food. Enjoy your body. Don't abuse either. Ain't that hard, people.
