[timwiseman]

Groceries make up a smaller percentage partially because they are so much cheaper than eating out.

As for it being healthier, it all depends on your choices. If I am eating in, but having noodles and microwave pizza it will be much less healthy than getting a salad out. I have been on business trips where I ate every meal at a restauraunt for more than two weeks, but it was a relatively healthy diet.