When we hear the words from our reading, "Do not be anxious about [...] what you will eat [or] what you will put on," we think the Lord is telling us not to spend so much time browsing the restaurant menu or standing in front of our shoe closet in the morning. But these are 'first-world problems' that come from a position of privilege almost 2000 years after these words were written.
Our Lord originally spoke these words to farmers and fishermen, people who might not get to eat dinner if they had a bad day at work, people who might not have anything to wear if something happened to their single spare change of clothes. Our Lord spoke to people who were just getting by, and He wasn't merely saying that there's more to life than appearance and luxury—He already said that in the Parable of the Rich Fool—now He was saying that there's more to life than even the bare necessities of health and survival! There's something more fundamental to life than even life & death.