How many of you eat or used 2 eat very little during the day because u forgot or just really busy and stresed.

Because i am with school i m15 male. I cant be botherd 2 eat no more i just gotta keep studyin 2 do well. well basically i n the mornin i l hav a cereal bar at lunch i dnt like eating infront of my friends lol and have a bit of dinner later on. My mom keeps saying its bad; but i dnt relaly care. wats so wrong who care about eating, shes saying the my weight is reducing too much. so what though nothin i can do about it. thanks for helpin though.