One way to avoid gaining weight is knowing the right foods to buy when youre in the supermarket. But enticing packaging and nutrition labels with words you cant even pronounce make it hard to select healthy choices. Janis Jibrin, a registered dietician and the author of Good Housekeepings new book, The Supermarket Diet has a few good tips on how to buy the right foods.

Fiber is very important for people trying to lose weight because it makes you feel fuller longer," says Janis Jibrin, R.D., Author, "The Supermarket Diet." "Cereals vary greatly in the amount of fiber they contain. So the rule of thumb is, per 100 calories, you want at least 5 grams of fiber and 5 grams of sugar or less.

Janis also recommends whole-grain foods but says its not always easy to tell whether youre buying the real thing. A lot of packages look earthy, crunchy, and wonderful with stalks of wheat on them," says Jibrin. "For instance, the words multi-grain do not always mean they are whole grain. Unbleached wheat flour, that sounds great, but it is not a whole grain. And in some instances light means a product is light in flavor and light in color. No difference in calories, no difference in fat. So, once again you have to go to the nutrition facts panel. Check the calories. Check the serving size. Check the fat to make sure youre really getting a light product.

And Janis recommends buying whole fruits rather than fruit juices. You get fuller on fewer calories with the actual fruit. For example, Good Housekeeping says that a cup of apple juice has less than one gram of fiber and more than 100 calories. But a cup of sliced apple has more than 3 grams of fiber and just 74 calories.

For more smart shopping tips, check out the February issue of Good Housekeeping or visit www.goodhousekeeping.com.