Age is not merely the period of time one has lived, or of the physiological changes the body goes through during the course life. It is also a product of the social norms and expectations that apply to each stage of life. Age represents the wealth of life experiences that shape whom we become.
- The aging process brings about many changes in body composition, often without concomitant changes in body weight.
- As individuals age, percent body fat increases while lean mass and bone mineral density decrease. The increase in fat mass is more specifically localized in the abdominal region, a body part more commonly associated with cardiovascular disease and diabetes.
- BMR (Basal Metabolic Rate)* is reduced in old age, reason being the reduction of muscle mass in the body.
- Mostly, age-related weight gain is due to a dramatic decrease in the calories burned. It is also due to the decrease in the BMR (Basal Metabolic Rate) - an older person tends to put on more weight when compared to the younger individual. This is because energy expenditure decreases with age resulting in decrease in body metabolism.
- BMR decreases with age; by 4 - 5% per decade. This happens after the person has reached 20 years of age.
- The decline is due to the increase in the fat mass. It becomes more rapid after the age of 40 in men and 50 in women.
- The number of calories burned per day decreases with age, thus, triggering easy weight gain.
*Basal Metabolic Rate is the rate at which the body uses energy while at rest to maintain vital functions such as breathing and keeping warm.