That depends upon what you want to learn about this subject.
Study these sites for some ideas.
I would limit it. Why don't you document the food intake of a group of teens?
how can i do community service about this topic
Post a poster with the results in the school cafeteria, write a news article, etc.
what can be inclued in the senior project about it
Did you read through the web sites I posted???
yes just need a little more
How about following Bobpursley's advice about doing a poster for the school lunchroom. Research the amount of calories needed for a normal teenager.
I can envision a poster with two columns or sections.
In one section, have a picture of a slim, attractive person. Then show a reasonable day's food intake with quantities and calories for each.
In the other section, have a picture of an obese person. Show the food that an obese person might eat in a day. Again include quantities and calories for each.
I have an obese friend who eats two or three times the amount I do at each meal. When one piece of candy satisfies me, she eats three or four pieces of that candy. The same is true of everything else I've seen her eat.
ok that sounds good