If you have to argue this position, you should focus on the impact that eating has on other students in the class and on the physical environment of the classroom.
You should talk about how a student who is eating in class can distract other students. The student's food might smell strongly and either bother other students or make them hungry too. A student might eat something noisy like potato chips and distract the class in that way.
Also, students who eat might spill their food. This could stain the carpets in the room. If there are no carpets, it would at least cause disruption because someone would need to clean up the spill, thus disrupting class.
The second post covers most of the issues. Eating in class creates trash, which many students fail to dispose of properly. It is distracting--to themselves and others--to the subject at hand: education. Around computer keyboards, it can be an expensive proposition. I have witnessed food being thrown at and stolen from others. I see know reason why students--and teachers--can't use their breaks between classes (not to mention lunch) to eat if they need to do so.
I find it hard enough at times to capture my students' undivided attention without them eating food. If they were to be noisily opening packets of chips, offering around candy, busying chewing large mouthfuls of sandwich, just think how much worse it would be! Distraction seems to be to be the strongest argument against eating in class.
I agree with poster 2. Students should not eat in class because it is a huge distraction. There are other ways it causes distractions. It is human nature that when one person has food, everyone wants it. So if one child has food, the others will be bugging him or her and begging to share.
I am a high school student, and yes I agree that students should not eat in class as they like. They might have a feeling of hunger, due to the fact that they had not eaten anything however it is wrong. This may cause distraction to both the student and his/her classmates. There is also a cafeteria provided so if they choose to eat, the cafeteria is available....
I know a rival school of mine when I was in high school, who was infested with roaches and rats because they allowed the students within the school to eat in class. So, if you don't want the school budget to be spent on fumigating rather than funding extracurricular activities or field trips, I suggest kids don't eat during school.