Basal Metabolism

Basal Metabolism.

The basal metabolic rate is the minimum caloric requirement needed to maintain the life of a person at complete rest. The basal metabolism of a person should be measured after a resting period in a place with a temperature around 20 º -25 º C and have been fasting for at least 12 hours.

Factors determining the basal metabolism.

The basal metabolic rate varies with each individual by a number of factors:

Genetics: Some people are born with faster metabolisms and others with slower metabolisms. Gender: In general, men have greater muscle mass and less body fat percentage than women. This results in a higher basal metabolic rate in men. Age: The basal metabolic rate declines with age. A possible approach is to say that after 25 years falls near 2 percent each decade. Weight: The more weight, increased basal metabolic rate. For example, the metabolic rate of an obese woman can be around 25 percent higher than that of a woman is obese. Body surface, is mainly determined by the height and weight. A greater body surface area increased metabolic rate. Taller people and large have a faster metabolism than smaller people and short. Body fat percentage: The lower body fat percentage and increased the muscle, the higher the basal metabolic rate. Diet: calorie-restrictive diets can lead to a loss of basal metabolic rate of between 15% and 30%. Glands: High levels of thyroxine or adrenaline increased basal metabolism.

Other factors that affect our energy needs:

Internal body temperature, metabolic rate is higher the greater the internal body temperature. Ambient temperature: A low temperature increases the metabolic rate as the body attempts to maintain internal temperature. Long exposure to high temperatures can also increase your metabolic rate. Calculation of Basal Metabolism.

Harris-Benedict

The known formula for calculation is the Harris-Benedict. This formula uses factors such as height, weight, age and sex to determine basal metabolic rate. It does not take into account a very important variable, body muscle mass. So the formula is not well approximated basal metabolism in very muscular or obese.

Men: BMR = 66.5 + (13.75 x weight kg) + (5 x height cm) - (6.6 x years old)

Women: BMR = 66.5 + (9.5 x weight kg) + (4.8 x height cm) - (4.7 x years old)

Katch McArdle

Katch McArdle formula: This formula uses only the amount of muscle mass and applies to both men and women.

Basal metabolic rate = 370 + (21.6 X lean mass in kg)

FAO, WHO and UNU

Experts from FAO, WHO and UNU also propose another set of calculations based on tables and formulas.

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