As the cost of groceries keeps going up, people are looking for smart ways to save money. Understanding the often-misunderstood food labels is a good way to save money.

A lot of people are confused about food labels. Fewer than half of the people who answered a poll in 2007 knew what the “sell by” date meant, and many thought it meant the last safe date to eat the food.

The lack of federal rules and standard definitions for food labels is what Dana Gunders, executive head of ReFED, says is causing the confusion. Laws change from state to state, which makes the problem worse.