What is the Basal Metabolic Rate?

The basal metabolic rate (BMR) refers to the amount of calories a person burns over a 24-hour period to maintain his bodily functions only. This includes heartbeat, breathing, digestion and organ support, which all require energy, usually expressed in calories. The rate does not take into account exercise or daily calorie expenditure through normal activities such as shopping, working, gardening or household chores.

For individuals, knowing their basal metabolic rate can be a handy tool for budgeting calories to maintain, gain or to lose weight. Additional calories, based on a person's level of activity, are added to the rate to establish a baseline. All else being equal, falling below that baseline consistently will result in losing weight, maintaining the baseline will maintain weight, and consuming more calories will cause weight gain.

It is helpful to know that 3,500 calories equals 1 pound (0.45 kg) of fat. Falling below the baseline consistently creates an accumulative deficit, with each 3,500 calories resulting in the loss of 1 pound (0.45 kg). Many people find their weight slowly creeping up over time because they underestimate the amount of calories they consume in a day, regularly exceeding their baseline. A steady excess of even a handful of calories a day adds up over the long haul and results in accumulated weight gain.

There are many BMR calculators online that can give individuals a good idea of their rate by using their current weight, height, age, gender and activity level. The activity level considered here is not for the purpose of adding calories, but to identify athletes, as the BMR is adjusted for that body type.

Once a person knows his basal metabolic rate, he can add some calories to it to reflect his level of activity. If he has a desk job and gets little or no exercise, for example, his baseline might only be a few hundred calories above the base. For someone who exercises moderately, it will be a little higher.

As a person's body changes, his BMR also changes, so it’s good for individuals to get new readings as they lose or gain weight. A person might want to recalculate the rate with every 5 to 10 pound (2.2 to 4.5 kg) weight change. He should also adjust the baseline if his activity level significantly changes.

Once the rate and caloric budget has been calculated, it may not be necessary to count calories every day. If a person's weight isn’t a problem and remains steady, there’s no reason to do so, but calorie counting might be the only way to take back control for many people struggling with weight issues. Fortunately, this can be made much easier with fitness software.

Most fitness software includes a basal metabolic rate calculator and will tell the user what his daily caloric intake (DCI) should be for his weight and activity level. Users can also set goals and draft plans that will establish a daily regimen to achieve a set goal weight in a given amount of time. Fitness software tracks calories, nutrients, exercise, and, in some cases, medical conditions, making it very easy to keep track of calories and progress. These programs come with pre-loaded food lists covering the vast majority of brand name and common foods the average person might eat, and users can typically add their own foods.