Fitness

is described as the ability to distribute oxygen to the body during physical activity

Metabolism

are the chemical changes in living cells, the ability of cells to break down substances and convert them to energy. Commonly recognized as the ability of the body to burn and utilize fat.

Cholesterol

helps to make up the cell membrane, but is also linked strongly to heart disease. It builds up on the walls of arteries and restricts the blood flow. High levels of cholesterol are very unhealthy.

Obesity

is being very, very overweight and having a high accumulation of fat.

Protein

is found primarily in meat, fish and dairy products like milk. Proteins are vital to rebuilding and repairing living tissues so a high amount of protein in ones diet is very important.

Carbohydrates

are organic compounds such as sugar and starch that are the major energy sources for all animals.

Sources:
dictionary.com