The following excerpt is from The Volumetrics Weight-Control Plan.¹

I live on good soup, not fine words. - Molière

It's mostly water. Yet our bodies perceive it as food, not drink. Soup based on broth, rather than cream or a starchy puree, is at the low end of the energy-density spectrum.

The satiety difference between water consumed on its own as a beverage and as an ingredient in soup is remarkable. We demonstrated this when we gave women a 270-calorie first course before lunch. On some days, the women got a chicken-rice casserole. On others, they got the same casserole plus a 10-ounce glass of water. On another occasion, they got the casserole with an extra 10 ounces of water cooked into it to make soup. It was only the soup that reduced the calories they ate at the lunch that followed — see this diagram for details.

Not only did the women consume about 100 calories less at lunch after the soup, they didn't feel hungrier later, and didn't eat more at dinner to make up the difference. In Paris, experimenters recently reported the same thing: Water as a beverage with a meal didn't enhance satiety, but the same ingredients made into soup did. Chunky soup, they found, was more satiating than strained soup.

"The stomach empties liquids differently from solids, and lighter, more dilute liquids differently from heavier ones," says Penn State professor Kenneth Koch. "The water you drink is long gone by the time a water-containing food like soup empties from the stomach." Soup may contain some fat that slows its release from the stomach, and it also contains pieces of solid food, either tiny or in big chunks, that the stomach needs to break down further before sending it on to the intestines. "When you cook a noodle, it absorbs water, but our stomach no longer recognizes that as water-it now identifies it as a noodle," he says.

So the next time you feel hungry, try a large soothing bowl of broth-based soup. If you have it as a first course before lunch, it will be easier to eat fewer calories for your lunch, and you probably won't eat more at dinner. If you have it as a first course before dinner, you'll likely eat less at that meal, too.

TO DROP WEIGHT, PICK UP YOUR SOUP SPOON

In the early 1980s, Henry Jordan, M.D., then at the University of Pennsylvania, asked 500 people in a weight loss program to record every meal they ate for 10 weeks. Some were instructed to eat soup at least four times a week. The more soup they ate, the fewer calories they took in and the more weight they lost. On average, they consumed 100 fewer calories a day compared to people who had soup less frequently.

Eating more soup also helps you keep weight off. At Baylor College of Medicine in Houston, overweight men and women on a low-calorie diet who were instructed to eat soup every day liked the strategy better than those just reducing calories, and they maintained their weight loss better over the following year. "Soup works," says Baylor's John Foreyt. "It helps people to eat less."

SOUP AND SATIETY

"Beautiful soup, so rich and green, waiting in a hot tureen!" wrote Lewis Carroll in Alice's Adventures in Wonderland (1865). "Who for such dainties would not stoop?" If it's a good soup, hearty but not heavy, it will fill you up, give pleasure to your tongue and mouth and nose, deliver a visual message to your brain that a large satisfying food is about to be eaten, and activate a series of biological signals that tell you that you've had enough to eat.

The main reason is soup's low energy density. At the Eating Lab, we found that when we gave people a broth-based soup before lunch, they ate less than if we gave the same number of calories in an appetizer of cheese and crackers. It's not surprising, once you realize that a 200-calorie pre-lunch snack of cheese and crackers weighs only 11/2 ounces while our soup weighed 20 ounces (21/2 cups). We know it is not soup's temperature that is responsible for its satiating power---cold soup worked just as well as hot soup.

Soup evokes satiety in just about every way we know a food can. When you start a meal with a cup or more of soup, you see a reasonable portion in front of you. This visual cue leads you to expect that it will be filling. The same phenomenon happens when we eat a big portion of any food of low energy density, whether it's a salad or a bowl of cereal with fruit. Now you have your first sip. If you like it, you'll experience pleasurable sensory stimulation: the aromas that waft into your nose, the tastes of sweet and sour and bitter and salty on your tongue, the warmth as you swallow. With a big portion of low density soup, you get a lot of sensory stimulation. We know from our studies that the more sensory stimulation you get from a food, the more satisfying it is. We need a certain amount of chewing, savoring, smelling, tasting, and swallowing to feel that we've eaten enough of a particular food.

As you swallow spoonful after spoonful of the delicious soup, it moves down your throat into your stomach, where its big volume fills up your stomach. It activates the stomach's "stretch receptors," sending satiety messages to the brain. The more food, the more of these messages get conveyed. "Even if the calories are low, if you consume a big weight of food, your stomach still has to do the same amount of work, and it takes the same amount of time," says Koch.

As the soup empties from your stomach, satiety hormones are released into the blood, which help us feel full. If you eat soup with high-fiber whole grains and vegetables, as well as meat, it will leave the stomach slowly. As the soup is digested, some of its calories are converted into blood sugar (glucose), which causes insulin levels to rise, and these also provide the body with signals about how much food has been eaten. This exquisite sequence of events, which follows eating, is critical for satiety.

Soup is an ideal food for activating these mechanisms. Is it unique? Of course not. Any food that's low in energy density will allow you to consume a satisfying portion and reduce hunger with relatively few calories. If you don't like soup, start your meal with a salad, a piece of fruit, a glass of vegetable juice, or any first course that's low in energy density.

SOUP STRATEGIES

Don't even think of living on just soup. When I (Barbara) appeared on the ABC program 20/20 In 1998, explaining the principles that would form the basis of this book, the segment began with a profile of a woman on the "cabbage soup" diet. Whenever she was hungry, she explained, she was supposed to eat cabbage soup, morning, noon, or night. She looked miserable! Several months later, when she was re-interviewed, she had regained the weight lost on that diet. If you follow such a highly restrictive diet, you may eat less for a while out of sheer boredom, but you will not be able to sustain such a strategy.

If you like soup, on the other hand, you may find it enjoyable to eat it frequently. Have it as a first course, or as a main meal. Open a can, pop a paper container in a microwave, order it when you're eating Out, or make your own, perhaps freezing it in single servings you can microwave when you want a bowl. Soup is only part of the answer to eating fewer calories while enjoying one of life's pleasures: food. Soup-only diets don't work. But soup does.

SUMMARY

• Eating soup as a first course will help you to eat less and lose weight.
• Broth-based soup is very low in energy density so you can eat a satisfying portion with few calories.
• Water, which lowers the energy density of a food, must be incorporated into the food to enhance satiety.
• Eat broth-based soup, as a first course or as the basis for a meal, as often as you feel is practical for you, or start your meals with other low-energy-dense foods, like salad, vegetable juice, or a piece of fruit.

200 Calories of Soup

If you're watching calories, soup is almost always a good choice. It depends on the kind: If it's broth-based, it will be low in energy density, but if it's cream-based, all bets are off. For each soup we'll list the energy density and show you how much you can eat for 200 calories.