Consider the difference between a fresh grape which has loads of water and dried raisin which has very little. One grape and one raisin have the same number of calories (about 5). So, if you ate 20 grapes or 20 raisins, you’d eat about 100 calories either way.
But 20 grapes would have about four times the volume of 20 raisins, and take up more room in your stomach than 100 calories of raisins. For the same number of calories, the watery grapes are going to be a lot more filling than the dried raisins.
Here’s another example… What happens if you put a stack of lettuce leaves or cucumber slices on a sandwich instead of cheese? An entire head of watery lettuce has only 25 calories, and an entire cucumber has only 10. But a single slice of Swiss cheese will cost you 100 calories. So, by piling up the veggies on your sandwich, you can pump up volume without adding very many calories. This is also why salads make such good meal starters: they take up plenty of room in your stomach at a relatively low calorie cost, as long as they’re not drenched in dressing.
Most soups are another great meal starter for the same reason. A small bowl of low-fat, brothy vegetable soup will take up a fair amount of room in your stomach. But because it’s full of water and high-fiber veggies, it will only set you back about 100 calories or so. By the time your entrée arrives, you’ve already started to fill up. That means you can probably cut back on your dinner portions and save some calories.
This is also why I often suggest that you double up on vegetables and skip starchy sides at meals if you’re trying to cut calories. For the 200 calories you’d spend on a serving of steamed white rice, you could eat ten times the volume of roasted cauliflower.
Actually, sneaking vegetables into anything is one of the best ways to add volume to a meal with very few calories. So, add chopped or grated vegetables (carrots and zucchini work especially well) to dishes like soups, stews, meat loaf, casseroles, grain dishes and pasta sauces. Try folding plenty of steamed spinach into an egg-white omelet, or adding cooked butternut squash to your protein shake.
If watery, high fiber foods are the ones you want to turn to when you want to eat more and spend fewer calories. You’ll want to turn away from fats and oils. Since they have no water or fiber in them at all, fats and oils contribute the most calories to your diet in smallest volume of food. Think about this: a teaspoon of oil has the same number of calories as a whole fresh tangerine—but which one would fill you up more?
Here’s another trick: Add a little “air” to your protein shake. Next time you make your shake in the blender, try whipping it up for a while to pump up the volume. Making your shake bigger won’t boost the calories one bit—but it just might fill you up a whole lot more.
Written by Susan Bowerman, M.S., RD, CSSD, CSOWM, FAND – Senior Director, Worldwide Nutrition Education and Training https://discovergoodnutrition.com/2014/05/eat-more-stay-slim/