One of the great myths I hear as a nutritionist is that healthful eating will leave you starving—that maintaining a normal weight means a life of skimpy portions, unappetizing foods and great sacrifice. Indeed, one of the most common reasons people give for abandoning diets is that they were simply hungry, or unsatisfied.
"Satiety is the missing element in weight management," says Barbara Rolls, professor of nutrition at Penn State. "Cut calories by simply eating less and you'll feel hungry and deprived." With this in mind, Rolls and colleagues at the university's Eating Laboratory have cleverly manipulated food ingredients to satisfy both body and mind. Strategies they have created can help people select satisfying foods with fewer calories to replace the fattening foods that two-thirds of North Americans now consume to excess.
For example, young men who were test subjects at the lab found strawberry smoothies that had been frothed up with air more satisfying than deflated versions with identical ingredients and calories. Because the men perceived the bigger volumes as more filling, they ate less food at subsequent meals. When the researchers varied the content of pasta salads served to women under test conditions, the subjects chose to eat the same amount of food daily, even when lower-calorie vegetables replaced some of the pasta.
Outside of a laboratory, most of us don't precisely measure the foods we eat, but from one day to the next we are more likely to consume consistent amounts of food, while calories vary dramatically. Rolls's research demonstrates that we eat fewer calories if we pump up foods with air or water to fill our bellies, and if we flavor them to satiate our senses.
Seeing vegetables and grains in a soup or salad, for example, gives us visual stimulation that the brain reads as "plenty." Stretch receptors found in the stomach's muscles signal the brain when "plenty" has arrived. But the volume indicator has its nuances. A glass of water quickly flowing past stretch receptors does not trigger the "full" signal, but that same water, when consumed as soup, becomes part of the food, upping the satisfaction level and signaling "enough."
Beyond volume considerations, satiety depends on the type of ingredients. High-protein foods produce long-lasting satisfaction because when protein breaks down, its amino acids trigger hormones and neurotransmitters that inform the brain that satiety has been reached. High-fiber, good-chewing foods boost satisfaction and slow down digestion to help prevent between-meal hunger.
For Jill O'Nan, a freelance business writer in California's Silicon Valley, the eating plan explained in Rolls's book The Volumetrics Weight Control Plan (HarperTorch, 2003) has worked. When O'Nan first came across the
book (co-authored by Robert A. Barnett), she had been eating meals centered on large servings of meat and potatoes, the staples of her Irish-American heritage. In previous diets, she had cut back on portion sizes to lose weight. Despite initial success, hunger always interfered, causing her to backslide. Using Rolls's strategies, O'Nan pumped up the volume of her meals and found the satisfaction she had missed.
For example, vegetable curry soup fills her up, while coarse bread and other whole grains add staying power. A dinner of salmon, wild rice and green beans gives O'Nan greater satisfaction than a small hamburger and fries—but with fewer calories. For dessert, 12/3 cups of sweet grapes looks and feels like more than a meager 1/4 cup of raisins (the same number of grapes without water) for equal calories.
