The calorie, fat, and nutritional content of a smoothie depends on what you put in it and how much you drink. Smoothies made with only fresh fruit are fat-free and very low in calories. For example, a smoothie made with 1 /2 cup of fresh pineapple, half a banana, blueberries, and ice fills a 10-ounce glass for only 183 calories, yet is chock-full of B vitamins, vitamin C, fiber, and minerals.
On the other hand, a smoothie made with ice cream, whole milk, peanut butter, or other high-fat items, can supply more than 500 calories per 10-ounce serving. For example, a popular power smoothie for athletes contains milk, cottage cheese, peanut butter, a banana, and honey for a whopping 613 calories and 41% fat calories. You save yourself 83 calories and 11 grams of fat by switching from one cup of whole milk to nonfat milk and from creamed cottage cheese to nonfat cottage cheese! Other calorie crunchers include switching from ice cream to nonfat plain yogurt, fat-free vanilla frozen yogurt, or tofu, and limiting the size of your smoothie to 10-ounces or less.
You are right that smoothies are filling. That’s because they combine the two best filler-uppers – water and fiber. Researchers at Pennsylvania State University identified an important reason why we feel full after a meal. It’s a weight thing. No, not body weight, food weight. People stop eating when they have consumed a given weight or volume of food, regardless of its calories. Give people different sized servings of beverages that all contain the same calories and the people who drink the greatest volume eat less later in the day. In short, you’ll fill up on say a pound of food; you’re overeating if it’s 2,000 calories in a pound of chocolate, but munching for health if it’s 195 calories in a tall glass of carrot juice.
That brings us back to smoothies. Foods weigh the most when they’re packed with water and fiber, which could be the reason why low-calorie, fiber-rich smoothies made with fruit, nonfat milk, and other low-calorie items fill us up quicker than a bag of rice cakes. Another study from the University of Sydney in Australia, where researchers fed people 38 common foods and measured the hunger/food intake for the next two hours after the meal, found that people consumed fewer calories, yet felt more satisfied after eating fiber-rich foods, such as fruit, than when they ate croissants, cake, doughnuts, and candy.
A smoothie is a great quick-fix nutritious breakfast or snack, just make sure you use low-fat ingredients and keep your serving to the size of a glass, not a pitcher. The basics to whipping up a nutritious, low-calorie smoothie are:
Use juice or frozen fruit juice, nonfat milk, or fat-free frozen yogurt as your base.
Add fruit, fresh, frozen, or canned in its own juice. Frozen fruit gives a thick consistency. Choices include bananas, berries, mango, papaya, or oranges.
Add flavorings for variety, such as vanilla, coffee (instant or brewed), nutmeg, cinnamon, malt powder, or cocoa.
Sweeteners are optional, and include honey, maple syrup, fruit spreads, and sugar substitutes.
For a protein and calcium boost, add powdered nonfat milk, fat-free cottage cheese, or nonfat evaporated milk.
For texture and more nutrients, add toasted wheat germ, flaxseed meal, or oat bran.