If the idea of eating unlimited amounts of food without counting calories or grams of anything sounds appealing, listen up. Carefully.

Weight Watchers, which prides itself on the use of "points" to help members make food choices, limit portion size and control calorie intake, has just launched a program called the Core Plan. It's designed to reach the overweight person who is tired of measuring, recording and otherwise tracking food.

Although it isn't a low-carb plan, Core takes a chapter from those popular regimens: It relies on lists of "core" foods that, if used as the center of an eating plan, will help people consume fewer calories without counting calories or measuring portions. To match the weekly one- to two-pound weight loss generally achieved with traditional Weight Watchers diets, adherents must stick entirely with foods on the lists and get plenty of so-called lifestyle exercise, such as taking the stairs or walking around the block.

Core doesn't replace Weight Watchers' flexible point system. It's simply an alternative to that well-established program, now offered at 46,000 weekly groups in 30 countries. The Flex Point system assigns a number to each food portion and has participants stay at or below a certain total daily to lose weight. For instance, a chicken breast without the skin counts for three of the 24 points allowed each day for a typical dieter weighing 175 to 200 pounds.

The new program is aimed at those who don't "place a high value on [being able to eat] anything and everything, but say that there are too many food choices," said Weight Watchers chief scientific officer Karen Miller-Kovach. "They would rather have a smaller universe of food. The idea of eating off of a list of foods and not having to measure portions or count calories appeals to them."

So what do behavioral experts think about this approach?

"On the positive side, there are decades of psychological research pointing to the value and effectiveness of choice," said John Norcross, professor of psychology at the University of Scranton and co-author of "Changing for Good" (Avon). "It's true whether it's a meal plan or a medical regimen. If you give people choice, they feel more involved, more empowered and have higher compliance rates."

But on the flip side, Norcross said, "What people desire is not always what's good for them. I am battling the temptation to cynically conclude that this is a marketing plan more designed to recruit new members of Weight Watchers than to educate people about permanent weight loss. I hope I am dreadfully wrong about that."

To craft the Core program, Weight Watchers conducted large surveys of members and nonmembers in early 2003, just as the low-carb frenzy began sweeping the nation.

"Many people following the low-carb approach said it had nothing to do with the food," Miller-Kovach said. What they reported attracting them was the notion "of eating off of a food list and not having to count calories and track portions," she said. "It was an aha moment for us."

Trouble is, eating unlimited amounts of food doesn't necessarily lead to lower calorie intake or a nutritionally balanced diet. So Weight Watchers put together a team to draft lists of nutrient-rich foods. About 27,000 foods were reviewed.

Not surprisingly, those highest in calories didn't make the cut. Also eliminated were foods known for "abuse potential." These "comfort" or "trigger" foods include such favorites as chocolate, potato chips and cookies. Even some low-calorie foods such as meringues were slashed "because people usually eat too many of them," Miller-Kovach said.

Weight Watchers then tested the program on 10,000 people at eight centers and found that more refinements were necessary for consistent weight loss. Among the foods that came off the list: nonfat, sugar-free yogurt -- a "light" food, but not calorie-free. "People were over-consuming it," Miller-Kovach said. "They would have an open container on their desk and just eat it all day long." Likewise, bread does not appear on the list of core foods, also because it's so easy to eat too much of it.

All but four whole grain cereals were cut, because too many people were snacking on many types of cereal throughout the day. Weight Watchers also added rules to reduce such mindless munching: Cereal can be eaten only with nonfat milk and no more than once a day.

Brakes were also added for such popular foods as ground meat (93 percent fat-free or leaner); potatoes; whole wheat pasta and brown rice: All are allowed just once per day and can be eaten until participants reach a "comfort zone" of fullness. Healthy oils, such as canola, olive and safflower oil, are okay, but no more than two teaspoons daily.

The bottom line "is that the new program responds to consumers' desires for simplicity and ease," University of Scranton's Norcross said. "Humans crave simpler and quicker solutions to complex problems. And the newest Weight Watchers program attempts to accommodate this natural human craving."

But he also worries because, he said, "we know that simple solutions for complex problems are not effective."

Here are some key aspects of the Core Plan:

Measure fullness, not calories. Endless eating of even low-calorie foods can add up. So the new program teaches participants to rate how full they feel on a scale of one to five throughout the day, especially just before and just after meals. "We want people to eat before they get too hungry and stop before they feel too full," Miller-Kovach said. The idea is "not how much can I get in my body, but how much do I need."

A lid on fat. Surveys found that many people who were drawn to the low-carb approach worried about eating too much fat. Food lists on the Core plan keep total fat intake at about 20 to 35 percent of total calories and are low in saturated fat, trans fat and cholesterol.

You gotta move. Burning more calories with increased daily activities is a key part of the program. "We try to focus on getting people to sit less," Miller-Kovach said. Structured exercises aren't introduced until the third week. That's because University of Pennsylvania researchers have found that when eating habits and rigorous exercise are started at the same time, they are more likely to be abandoned together during "slips."

Meetings matter. Weekly weigh-ins and group support are part of the Core diet, just as they are in other Weight Watchers plans. So are dues, which run about $14 per week. Weight Watchers also offers an online version at www.weightwatchers.com, which can be used alone or with the standard program. The cost is $46.90 for the first month online and $16.95 per month after that, or $65 for the first three months, plus $16.95 per month after that.

Limited indulgence. Restricting food too much rarely works long-term. So Weight Watchers added 35 extra points that participants can use weekly to splurge on that don't appear on the lists, including chocolate, wine and bread. For example, a slice of bread is two points; a half candy bar is three points; four ounces of wine is two points.

Flexibility. Participants can switch between the Core and Flex Points plans as desired. But Norcross warns that too much flexibility can have a downside: "You can keep people on a program by accommodating the inevitable vicissitudes of just living. But frequently, it leads to . . . a full-blown relapse" into overeating.

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