The shape of your body changes naturally with age. One cannot avoid some of these changes, but your lifestyle choices can slow down or accelerate the process.The human body is composed of fat, lean tissue (muscles and organs), bones and water. After 30 years of age, people tend to lose lean tissue. Muscles, liver, kidneys and other organs can lose some of their cells. This process of muscle mass loss is called atrophy. Bones can lose some of their minerals and become less dense (a condition called osteopenia in early stages and osteoporosis in later stages). The loss of tissue reduces the amount of water in your body.The amount of body fat increases steadily after 30 years. Older people can have almost a third more fat, compared to what they had when they were younger. The fatty tissue accumulates towards the center of the body, even around the internal organs. However, the layer of fat under the skin becomes smaller.