Why is it that animals that are herbivores have to eat practically every second of every day just to get the?!

Because, as you said, different species have different metabolisms. Different digestive systems have different requirements. For a carnivore, it takes a lot of energy to get one meal - the prey animal doesn't make it easy, and there's no guarantee the predator will succeed, therefor the end result has to be worth it. Meat tends to be quite dense, and carnivores usually have short digestive tracts, high stomach acid and so on to allow them to get the most nutrients out of it in the most efficient way.

In contrast, herbivores may have to roam over large areas to find enough food, but the food doesn't try to run away so they don't have to expend vast amounts of energy on catching it. Plants take longer to digest than meat and contain a lot of fibre, necessitating relatively weak stomach acid and a long digestive system to utilise it efficiently. Thus herbivores generally eat frequently, as a lot of their food is roughage and is passed out of their system.

Herbivores graze. Basically, they'll find an apple in the grass and nibble on that. Then, they run around for another hour or so looking for something else to eat. They basically run around all day looking for food, and the running is their exercise (which is why herbivores are extremely fat).
Carnivores eat a giant meal and then they're done. Obviously eating an entire deer would be more filling than eating half of a rotten apple.

Your adorable. Well try checking out some science Chanel's on animal life. Lions will spend a great deal of time finding, hunting, then eating their catch of the day without success sometimes. It doesn't happen as fast as you explain it to. So you have sat in front of a cow and watched in eat for every single second in a day? Oh you haven't? I watch them watch me sometimes, take care of their young, sleep, walk around. And in between those things, they will eat. I am an herbivore. And I live a wonderful active life while I only spend about 2 hours each day preparing and eating food.

Hello

We are all different, you only have to see bit fat obese meat eaters who eat all the time, anorexic or bulimic meat eaters, overweight vegetarians and underweight vegetarians. Overall, plant food is the best I feel.

not necessarily. rabbits have to eat constantly to keep their guts moving since they are unable to pass wind, which results in their stomachs basically turning into a huge balloon which will eventually burst!!

There are a lot more calories in meat than in grass.

Calories and much more. Ever notice how many different nuts and twigs and berries a vegetarian needs to supplement the lack of meat in their diet? vegetable matter only has trace quantities of the many vitamins and minerals most herbivores need in order to support their bodies. The body of a lion and an antelope for the most part need similar substances, albeit in different quantities, the difference is the lion eats the antelope and get not only the benefit of the antelope, but of all of the grass it's body has consumed, processed, and transformed into usable proteins, etc.