From how much of the body is muscle to what causes colour-blindness

We explore some of the curious questions that science can answer

About 8 per cent of male western Europeans are colour-blind (Getty/iStock)

How much of my body is muscle?

About two-fifths of a normal adult’s body weight is muscle, but the actual figure depends on the individual. Most teenagers have slightly less muscle because more forms as our bodies mature. 

Which is the smallest muscle in the body? Which is the largest?