If you want to buy food that may be better for you and the planet, you need to look at labels. But not all label claims are worth your dollars.

Walk down any supermarket aisle and you'll see a flood of labels. Food makers use them to grab your attention to make their product seem better than the competition. Some labels are helpful; you can trust them. Others are more marketing than meaningful.

Lisa Lee Freeman, the editor of Shop Smart Magazine, says the "organic" label is almost always worthwhile.

"Because it's backed by the U.S. government and there are very high standards for organic products," she said.

But Freeman says the one exception to organic labels is seafood.

"There's no organic certification standards for seafood, so it's just a waste or money on your part," she said.

Another label that's a waste of money -- "natural."

"There are really no standards for natural at all. It gets slapped on all kinds of products. Not worth it. So don't get organic and natural confused," she said.

When it comes to fish, "farm-raised" and "wild-caught" are meaningful because they tell you something about the fish. Take salmon, for instance.

"The 'farm-raised' salmon tend to have more toxins in their flesh, for example PCB's, than 'wild-caught' salmon," said Freeman.

On the other hand, when it comes to tilapia, Freeman says, it's better to buy 'farm-raised.' There's a Web site that can help you figure out which way to go -- blueocean.org.

Freeman says other labels such as "free-range," "free-roaming" and "cage-free" are basically meaningless unless accompanied by the organic seal.

"For caged-free, it may mean that the birds were not in a cage, but there were stuck in a dirty old barn.

"Free-roaming may mean that the birds were able to roam around in a barn, and maybe they had a few minutes with the door open, but whether they went out or not, it doesn't matter. The meat can still be labeled free-range or free-roaming," she said.

When it comes to beef, Shop Smart says you can trust these labels.

"'Hormone-free' is a good one to look for on beef as well as 'no-antibiotics.' That's meaningful. And 'certified humane' is also another good label because it means the cows actually had time out in the pasture eating grass, which we think is important," Freeman said.

It's important for you to know what the term "organic" means when it's used in different ways. For produce, you want to look for a label that says "organic or "USDA organic."

With packaged goods, the labels are different. If you see "100% organic," it means 95 percent of the ingredients are organic. And if it says "made with organic ingredients," it means 70 percent of the ingredients are organic.