Age-related muscle loss is called sarcopenia
Sarcopenia has been defined as an age related, involuntary loss of skeletal muscle mass and strength. Beginning as early as the 4th decade of life, evidence suggests that skeletal muscle mass and skeletal muscle strength decline in a linear fashion, with up to 50% of mass being lost by the 8th decade of life
much of this can be prevented through correct diet and exercise.
Less muscle means greater weakness and less mobility, both of which may increase your risk of falls and fractures. Research found that people with sarcopenia had 2.3 times the risk of having a low-trauma fracture from a fall, such as a broken hip, collarbone, leg, arm, or wrist.
Sarcopenia is also associated with acute and chronic disease states, increased insulin resistance, fatigue, falls, and mortality [
5–
7]. Of the chronic disease states, sarcopenia has been especially associated with rheumatologic conditions, especially rheumatoid arthritis (RA) in women
Sarcopenia in older adults
a longitudinal study of age-related changes in skeletal muscle and body composition in older adults, recently identified that increased fat mass was associated with lower muscle quality and an accelerated loss of lean body mass over 8 years.
Insulin resistance is increased through the loss of muscle, The body produces more insulin to compensate for the lack of sensitivity this becomes a problem as insulin is heavily involved with fat storage.
As we loose muscle our metabolism is reduced making it easier to over eat and combined with the increased ability to store fat from the increased insulin response it makes keeping body fat levels in a healthy range much much harder.
If we loose muscle it becomes much harder to regain it as we age and as muscle is built in calorie surplus if our metabolism is low and insulin resistance is increased the larger calorie intake needed to build muscle will mostly go towards laying down more fat stores.