Beach reading used to describe books that were light and entertaining. Now, perhaps as a reflection of our nation's growing girth, summer bestseller lists also include diet books that promise to make you lighter -- and presumably more entertaining -- on the beach.

Is their advice sound? Or will it fade faster than a summer tan? Here's a roundup of some of the books that have snagged spots on recent bestseller lists.

"Hungry Girl: Recipes and Survival Strategies for Guilt-Free Eating in the Real World," by Lisa Lillien (St. Martin's Griffin, $17.95). Blogger Lillien (www.hungry-girl.com) is quick to note that she's not a nutritionist. Nor is she a doctor, registered dietitian or professional chef. She's simply hungry and loves food.

Three years ago, this self-described "foodologist" began blogging about her cravings and food struggles to a couple hundred friends and relatives. Her blog grew into a daily e-mail newsletter, website and now, a bestselling book.

Lillien's philosophy is simple: no fad diets. In fact, no diet at all. Eat healthfully to reach a healthier weight -- a message that fits well with the Lean Plate Club approach. This isn't really a diet book, but rather a cookbook packed with dishes and meals that are reduced-calorie, low-fat and high in fiber.

Some of the recipes were developed in conjunction with Weight Watchers. All include nutrition information. Many are more healthful versions of tempting foods. Among them are favorites such as cheeseburgers, pizza and onion rings, as well as chocolate peanut butter fudge. There's even a chapter called "Chocolate 911," a nod to the food cravings that can often sabotage the best weight-loss plans.

Lillien knows from experience that portion control is key. So most of the recipes in this volume are for one serving. That takes the guesswork out of calculating how much to eat. (Double, triple or quadruple the recipes for larger crowds.) "Hungry Girl" also makes clever use of some healthful, but often overlooked, foods. Two to note: Portobello Skinny Skins and Bake-tastic Butternut Squash Fries.

One criticism is that many of the recipes are very high in salt -- a misguided strategy often used to compensate for taste in reduced-calorie foods. I'd love to see Lillien tackle flavor with herbs, spices and other seasonings that are lower in sodium. Based on this clever book, my bet is that she will be up to the task in upcoming volumes.

"Skinny Bitch" (Running Press, $13.95) and "Skinny Bitch in the Kitch" (Running Press, $14.95), by Rory Freedman and Kim Barnouin.

Freedman is a former agent for the Ford modeling agency. Barnouin has a master's degree in holistic nutrition. Both have a lot of attitude and lace their books with plenty of salty words.

Their message is this: Go vegan. That means giving up all animal products, something that will be too extreme for many.

Kudos to the duo for underscoring the importance of giving up smoking, but some of their other advice is questionable. They claim that organic red wine is more healthful than other wine, which is not the case. They call sugar the devil, then suggest substituting turbinado sugar, raw sugar, agave nectar or molasses for refined sugar. These are all added sugars and should be eaten in moderation. Read this book for fun and possible recipes, but be skeptical of its nutritional information.

"South Beach Diet Supercharged: Faster Weight Loss and Better Health for Life" by Arthur Agatston with Joseph Signorile (Rodale, $25.95). Often billed as "Atkins light," the South Beach Diet is a low-carbohydrate, high-protein diet that is less extreme than Atkins. The South Beach approach, created by Agatston, a Florida cardiologist and bestselling author, has spawned a line of food products made by Kraft.

Successful long-term weight loss means finding the right balance between calories eaten and calories burned. One valid criticism of South Beach is that it barely mentioned exercise. Agatston addresses that complaint with this book, co-written with a professor of exercise physiology at the University of Miami. It includes three phases of exercise that are a great way to ease into activity.

Other welcome additions include whole grains and more fiber-filled food. But fruit lovers, beware. The plan still eliminates all fruit from the first two weeks of the diet. What also still rankles is that the plan demonizes pineapple, watermelon, dates and figs -- healthy foods that are on the list of fare to eat rarely or avoid altogether.

The bottom line is this: No diet book works for everyone. The real secret is finding a healthful approach to food and activity that you can stick with for life.

You can subscribe to the free Lean Plate Club e-mail newsletter at www.leanplateclub.com. Sally Squires is a writer for the Washington Post.