Friday I wrote about the Fullbar, which when I remember to take 30 minutes before my two biggest meals of the day, really does fill me up. My friend Ronnie Fein commented that she was once told to drink a glass of tomato juice before a meal, and that, too, will make you eat less.

I’ve done a bit of poking around on the Web, and found a book – and lots of press – about “Volumetrics” by Barbara Rolls, PhD. Along with her colleagues at Pennsylvania State University, she discovered that if you eat as much as you want of foods that are high in fiber and water – aka fruits and vegetables – you will less at each meal. She also is in favor of a 30-minute before-meal snack.

In an article on Web MD, Rolls explained her diet’s key strategy: "Eat a salad or bowl of broth-based soup before the meal to reduce intake at the meal; or reduce calorie density by increasing water, air, or fiber and take out a little fat -- but not so much that the dish loses it taste."

How does it work? Foods containing water, air, or fiber have fewer calories than other foods and also cause the stomach to stretch and empty slowly.

Exactly was the Fullbar is all about.

In Volumetrics, at meal time, make sure there are at least one or more foods that are high in water and fiber, and add a lean protein -- meat, fish, poultry, soybeans, eggs -- to each meal. Protein is key for me. If a meal lacks protein, within a few hours I find myself ravenously hungry, which can translate into an eating binge.

What follows are foods, that according to Web MD, that will help curb your hunger. Eat more of these to eat less food and shed pounds:

• Fruits and vegetables
• Lean meats, fish, poultry, eggs
• Whole grains, like popcorn

In action:

• Add shredded or chopped vegetables to pasta and egg dishes, main-dish salads, and other mixed dishes, and use them to top pizzas.
• Eat whole fruits instead of fruit juices or dried fruits.
• Use a blender to whip air into fruit drinks, smoothies, or sauces.
• Choose whole-grain puffed cereals, popcorn, breads, cereals, and pasta.
• Enjoy vegetable salads or broth-based soups before meals.
• Top entree salads with lean meats, poultry, eggs, tofu, beans, nuts or fish.
• Add fruit to salads or enjoy as dessert.
• Add beans to stews, soups, egg dishes, and casseroles.
• Have lean protein or low-fat dairy at all meals and snacks.

It all makes sense and sounds so easy. Why then is it all so hard?