The most simple answer might be hormones. It could be that the person doesn't want to let the other individual down or think less of them.
Very open ended question here. It’s yes and no. There are autoimmune diseases that can manifest which you have no control over that can result in muscle wasting. So that being said no your behaviours will not always result in the avoidance of disease. When it comes to injuries, your behaviours can influence it. For example, by choosing to exercise you are increasing risk of injury acutely but also reducing risk of injury chronically. The aim is to get stronger for the long run while jeopardizing yourself through the process.
B) “Provides 22% of the DV of Vitamin A”
