Posted: November 5, 2011
Basal Metabolic Rate is defined as the amount of daily energy expended by humans and animals when they are at rest. This would be equivalent to the number of calories one uses if he or she stays in bed all day with no activity at all. Our bodies use calories for basic functions such as breathing, blood circulation, adjusting hormone levels, and growing or repairing cells. Basal Metabolic Rate accounts for 60-75% of the calories we burn every day and can be affected by genetics, gender, age, weight, stress, and illness. It is the minimum number of calories that the body needs to sustain itself in its present state. Our BMR decreases naturally with age and with the loss of lean body mass.
Several factors such as body size and composition affect BMR. Larger people or those with more muscle mass burn more calories. Men also tend to have less body fat, thus burning more calories. Food processing (digesting, absorption, transporting, and storing) can account to 10% of the calories we use daily. Physical activity accounts for the rest of the calories used after normal body maintenance.
Since we don’t have much control over our Basal Metabolic Rate, in order to lose weight, we must control it through physical activity. A deficit must be created both by consuming less calories and burning more calories through exercise. Fad dieting which consists of starvation or deprivation of any kind is counter-productive. This actually puts the body into conservation or starvation mode and slows down the metabolic process considerably.