Not sure what's in the canned or bagged foods your eating? Then learn how to read the label. In an article in The Pueblo Chieftain we learn:

Thanks to the Nutrition Labeling and Education Act of 1990, we have the advantage of knowing exactly what's in those chips and how many of them we can scarf down without fear of a waist expansion (hint: not the whole bag). All of the information is right there on the bag, box or can.

However, make sure you understand what you're reading. The Chieftain goes on:

It sounds simple, but those little information boxes can be tricky, especially for those who aren't accustomed to monitoring their food intake. To help explain, we asked Mary K. Sanford, the lead clinical dietitian at Parkview Medical Center, to guide us through a typical nutrition label and share some of her insights. Additional information comes from the U.S. Food and Drug Administration.

Warning: Although reading the label can give you an idea of what's in the product, be warned that some of the information may not be accurate. An article on CBC News.com tells us about the research being done by Bruce Holub, a food sciences professor at the University of Guelph:

While federal regulations legally allow for 20 per cent variability on the food labels, Holub said that up to 15 per cent of products surveyed exceeded the legal limit. Holub identified two products, breaded fish sticks and frozen breakfast waffles, as two offenders but he declined to name the companies that produced the products.

But it's a good idea to read those labels anyway. At least you'll have an idea of just how good - or bad - the product is.