Americans don’t give up easily. Those hoping to lose weight have put a whole new crop of diet books on the best-seller list. The science-laden “You on a Diet,” the wine lover’s “Sonoma Diet,“ the manly “Abs Diet,” and the kinder, gentler, Oprah Winfrey-endorsed “Best Life Diet” are just some of the recent titles.

We have rated those four and other popular diet books, based on our nutritional analysis and the critiques of a panel of diet experts. None of these books has yet been put to the acid test of a large clinical trial. Our analysis found that most provided good nutrition advice, but the panel perceived real differences in their quality of information. Some of the experts, for instance, thought that some nutritional theories in “UltraMetabolism” didn’t have solid science behind them.

We also have some new winners among diet plans that have been studied in clinical trials, reflecting data published since our 2005 diet Ratings. Our top-rated diet is “The Volumetrics Eating Plan” by Barbara Rolls, Ph.D., a professor in the department of nutritional sciences at The Pennsylvania State University.

Weight Watchers came in second, with Jenny Craig a very close third (see Diet plans, available to subscribers ).

We’ll also brief you on the real progress that scientists have made in identifying eating patterns and behavioral tricks that help at least some dieters cut calories without feeling too deprived. Most of those strategies appear in the diet books we evaluated. Whether those insights will translate into a widespread improvement in weight-loss success remains to be seen. But if you’re looking to shed pounds, there’s some solid science on which to base your choice of a diet plan or book, or create a do-it-yourself approach.