Don't leave extra food on your plate as leftovers
You don't have to sample every dish the host serves, but you should nonetheless eat everything on your plate out of respect for the cuisine, which is revered in Hinduism. Take only as much food as you can consume because of this.
The likelihood that you'll run upon a host who insisted you have a little bit more may make this challenging. A little bit more still. A little bit more still.
Many people in India will continue to offer food despite your complaints that you are actually too full to eat it because this is an important aspect of being a gracious host. It's acceptable to turn down your host's offers again and time again because you don't want to take too much and waste it.