Choose locally grown produce
Fruits and vegetables grown on nearby farms require less fuel to transport, hence a smaller carbon footprint. Look for "locally grown" signs in the produce aisle.
These foods use fertilizers that aren't petroleum based, so less carbon products are used to make them. They're also pesticide-free, which means no run-off of dangerous chemicals into your water supply. (Also see Your 12 Best Organic Bets for a list of the best choices for your health.)
Mix in vegetarian meals
Going vegetarian or even just opting to organize more meals around vegetables and fruit instead of meat can lessen your environmental impact. Besides saving on energy to raise the farm animals, cows breathe out methane, and is one of the biggest causes of greenhouse gasses. "I made the decision to find at least two non-meat entrees my family will love every week," says Dawn Bolgioni, mother of two. "It's been a great way to get more vegetable-rich meals into our diet, and it's nice to know that it's good for us and for the environment."
Green your protein
About ten times as much fossil fuel is burned on average to produce animal protein compared to plant protein, so try soy crumbles instead of ground beef, veggie burgers instead of hamburgers, and soy "chicken" nuggets. Meat-lovers can still help by talking with their grocers about the green pros and cons of options like pork, grass-fed livestock, and organic and local meat and poultry.
Think in bulk
Spices, nuts, and trail mix in the bulk bins are often cheaper and use less packaging, which is better for the environment, but look for those in air-tight containers as oxidized nuts don't have the same health benefits.
Pick seafood that's sustainable and healthy
Some fish are over-harvested or are in undersupply to the extent that catching them may harm an ocean's ecosystem. In addition, some species of seafood pose health risks due to heavy metals and toxins that have built up in their systems. (See Choosing Sustainable Seafood for tips on what to buy.)
Buy recycled aluminum foil
Yes, it's available and requires just 1/20th of the fossil fuels needed to manufacture it as regular foil.
Remember your cloth bags
Tote them to the store instead of using paper or plastic. Think of all the space you'll save in landfills.