It's no surprise that you need food to survive. Your body depends on food to keep your energy levels up so that your brain, muscles, organs, and more can function properly.
When you don't eat, you get hungry, which over a period of time, can lead to starvation. In the starvation phase, your body has to get its energy from somewhere else. In this case, it'll start breaking down your body fat, which is why you lose weight when you starve.
It's not very good for your brain to have to use your body fat to energize itself; it wants glucose from actual food sources, and the fatty acids that it gets from breaking down your body fat don't provide it with everything it needs, which means you'll experience an impaired thought process while you're starving.
Not only does food taste good, it helps your body do what it needs to do!