Interesting fact:

An average human has about 24.9 trillion small red blood cells, around 1.4 trillion platelets. Fat and muscle cells don’t even show up on that scale, yet combined, they are responsible for more than half of your weight. By the way the combined weight of all the bacteria in your body adds around 4 pounds to your weight. Red blood cells outnumber all other cells in your body by a ratio of 8:1.