Answer all i will mark as brainliest

I haven’t seen the video so I can’t answer the first one

#2: Everyone’s body has different amounts of chemicals and nutrients and they’re different weights, so a customized prescription can be used to work best for that patient specifically.

#3: They might not want to because all those factors that are taken into account about the patient can change. Weight can go up or down, or they might not have eaten anything the day they measured the patient’s nutrition, and depending on how long the prescription lasts, taking something that’s for those specific numbers over a long period of time can be dangerous if the patient changes anything about their diet or exercise or weight or anything like that.