Globalized food production has been a boon to many, but its cost on the environment, society, and cultures remains too high. Buy local to support farmers near your home, to reduce the energy use in shipping your food, and to get the freshest food available. Buy organics to fight against harmful pesticides, hormones, and antibiotics in agriculture. Buy fair trade to promote good pay for the people who harvest your food. Buy the produce itself, without any packaging, to reduce your consumption of resources.
Even better, though, is not buying your produce! Grow your food from your own backyard. Look to your garden for fresh veggies and fruit, to starting up a beehive for honey, or to raising chickens.
If eating sustainably had to be summed up, it would be: Know where your food came from and where it is going. All with you, waste can begin and end.