The reason soup fills you up is that slowly simmered soups contain complex combinations of proteins from their ingredients. The stomach does not let the soup pass down to the small intestine until all of those novel proteins are broken down. The stomach fills up faster, and diners automatically eat less. Water-based soups, of course, are more effective for encouraging weight loss than cream-based soups.
The volumetrics diet isn't just about soup, however. There are many other foods that increase satisfaction with fewer calories.
· Salads with green leafy vegetables and tomatoes reduce appetite and increase satisfaction with the meal.
· Vegetables added to carbohydrate foods, such as spinach added to a risotto, or parsnip or mashed cauliflower added to mashed potatoes, or mirapoix added to noodles, add flavor and take up space in the stomach.
· Certain dry foods are easy to eat in excess. Chips, cheeses, pretzels, candies, jerky, and dried fruit pack calories but don't build satiety. Dr. Rolls doesn't tell her patients that they can never eat these foods, but that they need to eat them mindfully, in conjunction with moister foods that are higher in water content.
· Fiber increases satisfaction with a meal. If breakfast is a problem, consider eating oatmeal. The soluble fiber in oats not only is filling but also activates a hormone called cholecystokinin, which signals the brain that a "comfort food" has been eaten.
· Sugary beverages are particularly detrimental weight loss efforts. Juices aren't a lot better, although 1 cup (240 ml) of juice a day usually can be tolerated.
· Moist meats, such as pot roast, stews, and slowly cooked tender meats are preferable to fried meats, dried meats, and meats in mayonnaise, not just because of the calories, but because of the density of the calories. The fewer calories there are in a bite of food, the easier it is to eat all you want and lose weight.
· Fat-free desserts don't help you control your appetite. The knowledge that you are eating a fat-free food may even lull you into consuming more calories than you would if you knew you were eating a decadent dessert. If you are going to indulge in a fat-free dessert, opt for pudding or ice cream, not cookies or cake.