Have you ever wondered why some people can eat chocolate all day and not put on weight, while others just have to look at a piece of mud cake and pile on the kilos. It’s all related to metabolism. Metabolism is the chemical and physiological processes that occurs in the body to convert food into energy that’s used to provide fuel to our cells. We all burn energy at different rates. Our metabolic rate is influenced by various factors including, age, gender, weight, physical activity and health issues. The higher your metabolism, the more cake you can eat. Although you can't control your metabolism, it can be stimulated during exercise and with certain supplements.
The energy (calories) we expend over a day in order to survive is called our basal or resting metabolic rate. The term basal metabolic rate (BMR) refers to the amount of energy the body needs to maintain itself. This accounts for 50 to 80 per cent of our total energy use. An average male may have a BMR of about 1695 calories per day, meaning they can consume that amount of calories before their weight will be affected, while an average female may have a BMR of about 1409 calories per day. Energy expenditure is continuous, but the rate varies throughout the day. The lowest rate is usually in the early morning, which is why starting the day with just 10 minutes of exercise can jump-start your metabolism. If you want to shed a few kilos, you want to keep a raised BMR and the key to this is increasing your lean muscle mass.
Knowing your BMR is important if you want to keep your weight in check. You need to know how many kilojoules you can eat a day to maintain your weight. Your BMR can be calculated by the following formula:
- Women: 655 + (9.6 x weight in kilograms) + (1.8 x height in centimetres) - (4.7 x age in years)
- Men: 66 + (13.7 x weight in kilograms) + (5 x height in centimetres) - (6.8 x age in years)
To calculate your daily calorie intake multiply your BMR by:
- If you are sedentary (little or no exercise) : Calorie-Calculation = BMR x 1.2
- If you are lightly active (light exercise/sports 1-3 days/week) : Calorie-Calculation = BMR x 1.375
- If you are moderatetely active (moderate exercise/sports 3-5 days/week) : Calorie-Calculation = BMR x 1.55
- If you are very active (hard exercise/sports 6-7 days a week) : Calorie-Calculation = BMR x 1.725
- If you are extra active (very hard exercise/sports & physical job or 2x training) : Calorie-Calculation = BMR x 1.9
- Example: If you are a lightly active 35 year old woman who weighs 65kg and are 165cms then your BMR is: 655+(9.6x65)+(1.8x165) - (4.7x35) = 1411.5.
- Daiy calorie intake to maintain your weight: 1411.5 x 1.375 = 1940 calories.
- For weight loss aim to reduce your calorie intake by 15-20%.
Your BMR can be affected by a variety of factors, including hormonal problems, muscle mass and the types of food you eat. Overeating when you are stressed slows your metabolism. Proteins raise your BMR by 30 per cent, while carbohydrates raise it by just six per cent, and fats a mere four per cent. Being physically fit increases your BMR because the more muscle and less fat we have, the higher our metabolic rate (muscle requires more energy to function than fat). Some supplements that increase your metabolism include Blackmores Metabolism Advantage, Nature’s Way Metabolift Fat Burner, Hydroxycut advanced, and Blooms Melt Weight Loss Formula.