A guinea pig should be fed 3 times a day, but on different vegetables. Feed them fruits only once per week. Do not get used to feeding your guinea pigs with sugary fruits like bananas. Ensure that your pig has enough water all the time. For more details, go to http://www.mgpr.org/newsite/GP_Info/Guinea%20Pig%20Diet.htm.
When you fill a guineapigs food bowl don't fill it all the way. They don't usually eat it all right away. Fill it halfway and refill when necessary. they need 24/7 access to food and fresh water. Guineapigs need to eat a lot to keep digesting food. Their body doesn't work like ours or like cats or dogs. Example: they cannot throw up.