How do you write an essay in third person?
When you write an essay in third person, you do not refer to yourself in the essay, but instead use sources while writing.
For example, this is not the way you write a sentence in your essay with third person:
I feel as if school lunches are very bad because according to my research, children do not like how the food tastes anymore, and so they do not eat it.
This is not how you do it because you are using first person pronouns (I, my). Because of that, you can't list any sources in your essay.
Not to mention, "I feel" is not very assertive, and in writing an essay, it should be obvious that it came from your mind; thus, incorporating "I feel" or "I think" is unnecessary.
By putting it in third person, you are able to list sources, and you are encouraged to do so. That's why you're asked to write essays in third person.
This is the way your sentence should be:
School lunches are very bad because according to The New York Times, the 2012 Healthy Hunger-Free Kids Act causes children to not like how the food tastes, and so they do not eat it.
By writing in third-person, you are able to present evidence to your reader. So when you write in third person, show what you know, with evidence backing up your points.
It won't be as redundant as saying "I think/believe" or "I feel" when we know/hope you wrote the paper and you hopefully have sources to back up your claims.