My stomach growls obnoxiously loud, often during class or other silent activities, even when i eat a full meal. what causes this?

Many possible causes: You might be eating foods that give off gas when digested, or that you are allergic to. Another possibility could be yeast in the digestive tract. Some solutions: beano or simethicone can reduce gassy foods. Fresh garlic inhibits yeast in the gut. Pay attention to which foods might be causing this more often and try eliminating them from your diet for awhile to see if it changes.