Pig acts like she is STARVING

Question
Hi Jules,
Our female guinea pig who is 2 years old, but we got her from the pet store 2
weeks ago, so we are getting to know her.  At first she was timid, huddled up
when we set her down and even seemed scared of the treats we offered.  We
started handfeeding her fresh veggies and giving her floor time each day.  
The last few days she has gotten all this energy and is all hyper.  She's almost
aggressive, the way she grabs treats now, runs around squeaking, and shoves
her toys around in the "floor time" pen.  But I can't tell now whether she is
getting enough food or what.  She eats like a starving hostage!  I give 1/4 cup
guinea pig mix in the morning and 1/2-1 cup veggies at night (some lost in
her dumping it out or throwing it around).  Now I give her an extra 1/8 cup
dry food in the evening.  Every time I come near the cage or she hears a
plastic bag she squeaks for food and she always attacks it when I put it in her
cage.  She hasn't lost weight.  Does this seem like enough food?  

Answer
Hi Miriam,

 Your Guinea Pig is acting in the normal behavior. She is getting enough food, you are giving her just the right amount. Guinea Pig are known for squeaking when the hear a plastic bag. My girls act the same way, it is completely normal and yes she is getting enough food.
 
   Her behavior is normal, and nothing for you to worry about. All Guinea Pigs act this way when it comes to food from the fact that they forage for food in the wild and must eat quick and aggressively when in the open for fear of predators. So this is natural behavior for her, and your doing a great job taking care of her.

  Take Care now,
         Jules