Green smoothies contain liquefied vegetables and fruits, so one glass can contain several servings. While those smoothies may equal nutritional wins, they can also produce weight gain. The smoothies themselves do not directly cause belly fat, but their healthy ingredients and weight-smart reputation may blind you to the number of calories they actually contain. If you take in more calories than you burn, you'll gain fat -- some of it in your belly.
Belly Fat Causes
Green smoothies can end up as belly fat, but only if you don't balance the calories they contain with the rest of your food intake and your exercise routine. Too many calories, too little exercise, muscle loss and hormonal changes cause belly fat, not one specific food. That means you can enjoy your blender concoctions as long as you account for the calories they contain and adjust accordingly.
The Surprise Number of Calories in Smoothies
If you toss some green vegetables, yogurt, milk, a banana, protein powder and some wheat germ into your blender, your 2- to 3-cup smoothie will contain well over 500 calories. If you add additional fruits, nuts, peanut butter, chocolate sauce, flaxseeds, healthy fats or sweeteners, your calorie tally goes even higher.
Making a Lighter Smoothie
Small changes to your smoothie recipe can cut your calories in half. For example, you can switch from whole milk, which has 150 calories per cup, to fat-free milk, which has only 90. Opt for fat-free yogurt instead of full-fat. Use extra fruit instead of sugar or other sweeteners. The U.S. Centers for Disease Control and Prevention recommends ordering a child-sized smoothie if you don't make the drink at home.
Tips for Balance
If you weigh 155 pounds and you down a 500-calorie smoothie for breakfast, you can burn off those calories playing basketball, running at 2 miles per hour or cycling at 12 miles per hour for 60 minutes. If you run at a fast pace -- such as 8 miles per hour -- play handball or cycle faster than 20 miles per hour, you can burn that smoothie off in just 30 minutes. You can also reduce the number of calories from your daily meals and snacks so that, even if you have a 500 calorie smoothie, you still only take in the number of calories you need to maintain your weight or lose weight. A combination of calorie control and exercise usually works best at fighting tummy bulge.