As the body continues to age, less food will be required in order to maintain body weight or conversely, require less food in order to gain weight. Many individuals find that their basal metabolic rate changes drastically when they hit the age of 30, again at 40 and once again at 60. Basal metabolic rate or BMR is the number of calories required to keep the body alive if one is lying in bed all day. It is the number of calories burned by digestion, muscle and breathing. This number can be estimated using current height, weight, age and gender. There are other factors as well, but these four are the most commonly used in BMR calculators. The older the person, the less calories needed to maintain body weight.
