Sadly we have migrated away from eating whole foods in their natural state. Are we lazy or is it something else because this is the healthiest way to pack in nutrients and sate your appetite. Science hasn't improved on mother nature. Sorry GMO's. Why have so many of us resorted to blending or juicing our fruits and vegetables? I suspect its because its easier and faster to drink 2 apples, 1 lemon and bushel of kale than to actually go through the tedious mastication process. Besides who has the time to steam kale, chew up 2 apples and slice and squeeze a lemon when you can pulverize them in seconds and slurp them down? We are a fast food nation. Science shows that blending or juicing fruits and veggies will rob them of one the most precious and healthiest nutrients, fiber, and even worse may potentially spike your glucose levels leaving you more hungry and insulin resistant. Diabetes here I come!
Lots of people do juice fasts in order to lose weight quick. It works, albeit temporarily. Like most very low calorie diets, this produces results in the short term but it is not advisable or easy to sustain for the long haul. People drinking liquid food tend to gain more weight than whole food eaters because the quicker a food is consumed the more calories one tends to take in. It is true, nutrients in liquid food are absorbed more readily but so is the sugar. Not a good thing. This results in blood sugars rising faster and higher than the body can control. After the initial spike in blood sugar (mostly made from fructose - arguably the worst kind of sugar) and lack of fiber intake you will be hungry again. Plus people who are juicing on a regular basis rarely get in their 25-50 grams of recommended fiber per day. They have unhappy colons.
Here is one study that compared the calorie intake of a meal following the consumption of nothing, a whole apple, apple juice with fiber added, and regular apple juice. Here are the results Though the apple, applesauce and apple juice with fiber all had the same amount of fiber, there was a clear (and significant difference) in the effect of these 3 forms of apple on satiety and caloric intake.
The whole apple decreased calorie intake by 15% in the meal that followed
The apple sauce decreased caloric intake by 6% in the meal that followed
The apple juice with fiber decreased calorie intake by 1% in the meal that followed.
The plain apple juice actually increased total caloric intake by 3%.
You've come a long way baby?! Or not.
In regards to blending your fruits and veggies Dr. Robert Lustig in his book "The Bitter Truth About Sugar" has this to say:
"The problem is that the shearing action of the blender blades completely destroys the insoluble fiber of the fruit. The cellulose is torn to smithereens. Whiles the soluble fiber is still there, and can help move food through the intestine faster, it now does not have the "latticework" of the insoluble fiber to help form that intestinal barrier.The sugar in the fruit will be absorbed just as fast as if the juice were strained with no fiber at all. You need both types of fiber to derive the beneficial effects."
Unfortunately I cannot find any scientific research to back up what Dr. Lustig states but I can personally attest to feeling less full and sated after I drink a smoothie or juice as compared to eating the same amount of raw fruit and vegetables. Do juices or smoothies fill you up?
The Harvard School Of Public Health warns individuals not to have more than 4oz of juice per day. I understand that many people simply like juice and are not prepared to give it up. So here are a few things you can do to ameliorate some of the negative effects
Add fiber and/or fat to your juice to slow down the absorption rate - olive oil, apple pectin, psyllium etc.
Use mostly vegetables - they have less sugar
Use organic foods - no GMO's and no extra chemicals (unless you like that kind of thing)
Use spices that have anti-inflammatory properties - cinnamon, ginger, turmeric
Watch your portion size and check the calories and total sugar content
Invest in a good blender and make your own low sugar high fiber smoothies
Water is the healthiest thing you can drink and hydrates you a lot faster than any other liquid. H20 should make up the majority of the liquids you consume; a smattering of unsweetened coffee/tea and perhaps a glass of wine or two may also be beneficial. Many of the other beverages are made up of empty calories, high sugar levels and little fiber. Perhaps, instead of reaching for a juice eat some fruit or veggies and drink a glass of water, it'll be healthier and your colon will be happier.