Why does my cat ALWAYS want food?

My cat is a large one. She's about 20 lbs, but she's healthy. She's just a large cat. We feed her about 2 half cups of food twice a day. In the morning, maybe a half cup or so, and the same at night. But she always seems to be hungry. She'll eat and maybe 30 minutes later she's meowing at me to feed her again. Sometimes she eats to the point of vomiting it all up. Why does she have this insatiable appetite?

[nancyjac]

1/2 cup of food is not a lot for a large cat.  If she is over hungry, she is probably eating too fast and not chewing well enough and that results in the vomiting.  We feed our adult cats canned food in the morning but they have a bowl of dry food available that they nibble at throughout the day.  Most cats (unlike dogs) will stop eating when they are no longer hungry, so having food available to them at all times is usually a good way to go.  If you are concerned about her becoming obese, then use a lower calorie food.  She may still overeat during the transition from not having food available upon demand until she realizes that there will be more for later, but eventually she should be regulating her own eating based on her nutritional needs.

[opus88]

good advice...I'd also like to know what brand of cat food are you feeding?
sometimes its all calories and not much for nutritional needs therefore the kitty is always hungry.
My big himmie was like that when he was on a substandard canned food, I have since transitioned him to a higher quality food with 'no grains'...(not completely transitioned yet, I mix 50/50)...and I have seen a huge improvement in his appetite demands.

[AppleBr]

Lucky does just like that :-)
She Meows as if she was dying of starvation
But my personal opinion is that mine asks for food cos have nothing better to to or just want attention.
They have no worns,are heavier than the mother and are quite strong, so Its hard to believe food is not being nutritive enough.
They also are crazy about eating Loreena's adult food - together with their own kittens food.Joy ate a whole cup of that another night,God knows how she could reach that,I just noticed the cup empty and a round creature around ( it was midnigth and mercifully she didnt throw up :-) )

Loreena, on the other hand, its eating less nowadays,hope it doesnnt mean shes having food outside home ( dog's one for instance- now we have 2 in the neighbourhood)

[teddybears4ever2]

Stardust would eat until she exploded if she could.  I have had many cats that have had that problem.

[scarednconfused13]

Every cat I have had throughout my life has had this eating problem. We went to the healthiest food out there, and the problem still persists. We thought the problem with vomiting was hairballs, and on occasion it is of course, so we also went to a hairball control food. It seems like she coughs a whole lot more lately too. She's still agile and everything, runs around and chases the dog, but she still seems overweight.

[nancyjac]

Have you ever tried feeding on demand with any of your cats? Most animals, including cats, will eat all they can get when they can get it because they instinctively know that they may not be able to eat whenever they are hungry.  By establishing a routine of small feedings twice a day on a regular basis, you are reinforcing this instinct.  By having food continuously available, you are countering that instinct and eventually your cat will recognize that she doesn't need to gobble up everything she can get because there will always be food available when she is hungry.  

2 of my 3 adult cats are over 20 pounds.  They are not overweight, they are just large breeds.  My 3rd adult cat only weighs about 6 pounds, because she is a small breed, The all have had food continuously available since we had them as kittens or very young adults and have maintained their current weight for all of their adult lives.  My oldest adult cat is 14 and my youngest adult cat is 10.