It's basically the percentage of body fat, muscle and bone. You can change it by exercising a lot (cardiovascular in particular), eating less calories (dieting) or just eating more healthy things/ more foods with protein.
Explanation:
I had a question like this on a health/pe test last week
Bullying occurs due to lack of respect and one person thinks they are supperior in ther relationship. So to effectively prevent it is through mutual respect from both sides.
