Are powdered vegetable capsules a good way to get your 5 vegetable servings per day? Nutrition Diva explains why this may not be a good idea.
Q. "I've heard about capsules that contain powdered vegetable juice. It sounds too good to be true. Wouldn't the nutritional value of the vegetables get lost in the processing?"
A. Some of the nutritional value of the vegetables would surely be lost by processing them into a powdered supplement - but certainly not all of it. However, I don't think that popping a few capsules of powdered vegetables is the best way to get your recommended 5 servings a day. Part of the benefit of eating a lot of vegetables is the nutrients they contain. However, there's another equally important benefit.
Vegetables are very nutrient dense but not very energy dense. When you fill your plate (and your stomach) with vegetables, it leaves a lot less room for other less nutritious foods - like potato chips or brownies. People who eat more vegetables not only get more nutrients, they also tend to eat fewer empty calories.
See also: Nutrient Density vs. Energy Density
If you fulfill your vegetable quota by popping a couple of capsules of powdered vegetable juice, you'll get some good vegetable nutrition. But those capsules aren't going to take up any room on your plate or in your stomach...which may tempt you to eat more junk. And if you are eating lots of fresh vegetables, taking powdered vegetable supplements seems like an unnecessary expense.