Eco-friendly food is food grown, gathered, or harvested near the point of use.
Not only is eco-friendly food healthier, by virtue of being fresher the food looks, tastes, and lasts better than food procured by traditional methods and transported over long distances. If food looks and tastes better you'll have a reputation for serving fantastic food. And when restaurants have that kind of reputation they are busier than others. You will also save money and waste by not throwing as much food away. So you are making more money and spending less, making for a stronger bottom line.
By buying eco-friendly food you are supporting the local economy. Small farmers and ranchers are good for your community because their activities keep open space around your community. That's good for ecological diversity and creating fresh air. Buy from them to keep them viable and your community diverse and strong.
Another benefit of buying your food locally is that you are saving energy from transporting your food great distances. That lessens our dependence on oil, reduces air pollution, and decreases wear and tear on the roads. That's a subtle benefit, but one that benefits you in many ways.
And finally, locally grown and shipped food has reduced packaging, reducing your landfill donations and associated trash fees. Perhaps you have a rotation system whereby they take your empty crates or boxes when they bring in new supplies. Imagine having your food products brought in by someone who's selected the items for you and not added to your collection of boxes and plastic wrap to throw away. It sounds heavenly to me.
Serve healthy foods, organic foods, foods low on the food chain, and support your local food network. Eco-friendly food has great benefits to you and your guests.