Shouldn't it be acceptable to act natural instead of acting in a professional way?

In formal situation many people like to act in a professional way in order to keep their image even though they could’ve acted in a natural way as dictacted by their body and personal desire. For example, when you’re hungry you want to, and are supposed to eat, right? But people who are hungry in a meeting or working session wouldn’t eat because it’s regarded as unprofessional. I believe they should eat, or do whatever they naturally desire so long as it doesn’t hinder their performance, what others like or don’t like to see shouldn’t be the top priority. Other example would be, If you want to fix your make up or paint your nails you should be allowed to do it inside a meeting, right? You’re still technically listening to the people while doing that so it shouldn’t be seen as a problem. These are just some of the examples.

I believe our body’s needs and desire should take precedence over the ‘supposed image’ of our position. Why on earth should people judge others on something that is natural/mundane anyway? Since when mutual understanding has faded away and we’re enforced to act in a professional way? I will be more than happy to see a newscaster eating while she’s explaining the news, or a president chewing a bubble gum while giving a public speech, or other things that other people deem as unprofessional behavior. We’re still human being. The ideal view is to act in a natural way and for others to understand and accept natural behavior.