Are green smoothies really healthy for you or do they contain too much fruit and sugar? Should people who want to lose weight avoid them? Will they ultimately devastate your health?
These are just a couple of the controversies going around about green smoothies on the Internet, and it’s nothing new. There will always be people who claim that green smoothies are not as healthy as they appear, despite the many health benefits of blending fruits and greens in a blender (weight loss is the most commonly reported health benefit).
In this article, I will address some of the main concerns about green smoothies.
The Green Smoothie Weight Loss Controversy
It truly surprises me that there is even a controversy about using green smoothies for weight loss. Fruity green smoothies played an instrumental role in my 40-pound weight loss and they have helped thousands of people lose weight using my recipes and information on Incredible Smoothies.
I’ve been drinking green smoothies every single day going on my fifth year now and I easily maintain my ideal weight. And I eat WAY more fruit in a day than the average person eats in a week.
Nevertheless, there is a controversy about green smoothies and weight loss, so let me clear up some of the confusion for you.
Calorie Reduction Controversy: The most recent exposé about the “unhealthiness” of green smoothies cites this health study comparing the satiety of different forms of fruit (whole apple, apple sauce, apple juice and apple juice with fiber added) and how it affects total calorie intake.
The study found that eating a whole apple reduced calorie intake of the following meal by 15% while consuming apple sauce decreased calorie intake by 6% in the following meal. Drinking apple juice with fiber reduced calorie consumption of a meal by only 1% while straight up apple juice actually increased calorie intake by 3%.
Assumptions based on the data presented by this study suggests that eating whole fruits promotes a significant decrease in calorie consumption while pureed fruit is not as effective at reducing overall calorie intake. However, there is a big difference between a freshly blended green smoothie and cooked apple sauce. You can’t even compare the two as they contain different foods and are processed in completely different ways.
Furthermore, the conclusion of the study explicitly states that “more research is needed to test the effects of consuming different forms of fruit on energy intake over longer periods of time before conclusions about the role of fruit in different forms in weight management can be made.”
Of course, that doesn’t stop people from jumping to conclusions about green smoothies based on research comparing apples to applesauce.
In the context of green smoothies, they should be added to the diet. I do not ever recommend drinking a green smoothie only diet. Green smoothies are best used to support a plant-based, whole foods diet – not replace it completely.
Replacing one or two meals per day with a large, 300-500 calorie green smoothie can provide great weight loss results. Green smoothies can help people on a raw food diet, or a whole foods diet, consume sufficient calories of whole foods to help them lose weight while feeling satisfied.
A calorie-sufficient green smoothie MEAL will satisfy your hunger until your next meal and reduce overall calorie intake for the day as long as the rest of your diet isn’t atrocious. Drinking a green smoothie in the morning won’t undo a day of eating baked goods, cheese, pizza, ice cream and other fattening foods. Drink green smoothies as part of a whole foods diet and don’t forget to exercise.
Excess Calories From Green Smoothies Because You Are Not Chewing Them: I recently read an argument stating that drinking green smoothies could add up to 100 excess calories per meal because chewing burns calories, where drinking does not.
I’m not sure how they got the idea that chewing a meal consumes 100 calories. My calculations are closer to 27 calories consumed by chewing for a solid hour. In the grand scheme of things, burning 27 calories while chewing (for an hour, mind you) is not going to make or break your weight loss success.
If anything, you’ll burn more calories with green smoothies because they will be efficiently digested and provide more energy to exercise and live an active lifestyle. And your more likely to stick with it. It’s much easier and way more convenient to drink a green smoothie every day than it is to eat a giant bowl of salad. Even I don’t have time for lengthy grazing.
Blending Fiber And Weight Loss: So what about fiber? There is technically the same amount of fiber in a whole apple and a blended apple. Of course, the blended apple is broken down more thoroughly before you eat it than a whole apple. But does this make the blended apple less healthy and therefore sabotaging to weight loss?
That has not been my experience. As I mentioned above, green smoothies were instrumental to my 40 pound weight loss. They have helped thousands of people lose weight. I’ve received tremendous testimonials from people who have used my RESET 28 program for energy and weight loss. The average amount of weight lost during the 28-day meal plan is about 10 pounds. Green smoothies are part of my whole foods diet, so I’m not at all concerned about any fiber breakdown in a smoothie.
I will also repeat that I do not ever advocate a smoothie-only diet. Primarily, I use green smoothies to get greens into my diet. Green smoothies are the only way I can eat the amount of kale, dandelion and other bitter and healthy greens that I do every day. But green smoothies should not be the only thing you eat to lose weight or detox.
Green Smoothies And Sugar Intake (and How It Affects Glucose and Insulin)
Okay, let me begin by saying that drinking green smoothies, or consuming whole fruits will not and can not give you diabetes. There is zero scientific evidence for this.
For healthy individuals, there is no need to worry about the natural sugars in fruit.
Now there is concern about diabetics drinking green smoothies and overloading on carbohydrates. This is a valid concern. Diabetics must work with their doctor or dietician to establish an appropriate amount of carbohydrate intake per meal, then plan their fruit and green smoothie consumption accordingly.
Diabetics don’t necessarily have to avoid green smoothies or fruit, in fact, the American Diabetes Association encourages fruit intake. Those with metabolic disorders must regularly check their blood sugar levels and restrict or limit carbohydrates according to how their body responds based on their post-meal glucose readings.
In fact, I have heard from diabetics who have normalized blood sugar and lowered fasting glucose numbers after drinking green smoothies. I’ve published a story in Green Smoothie Inspirations about a type 1 diabetic who dropped his insulin requirements by 10% after drinking green smoothies, and this pre-diabetic woman no longer needs to take Metformin.
Of course I realize that these stories are not the same thing as double-blind, clinical trials conducted by scientists, but it does go to show that at least for some people (and my feeling is that this probably works for most) green smoothies help facilitate weight loss, healthier eating and provides energy for exercise, thus working in tandem to normalize blood sugar reduce risk factors for diabetes and complications of the disease.
HOWEVER – It is not necessary for non-diabetic people to pro-actively restrict fruit or green smoothie intake in order to prevent the disease as there is no evidence that drinking green smoothies, or increasing fruit intake, causes diabetes.
Now Let’s Talk About Fructose
There is also a general fruit phobia and fructose alarmism that simply doesn’t make any sense whatsoever. Some of the most fruit-phobic people out there would have you think that eating a banana is on the same level as eating a glazed donut! That’s right, fruit is now “junk food”.
Here’s the facts: There is ZERO scientific evidence that consuming fresh, whole fruits or drinking freshly prepared green smoothies causes excess weight gain, or any of the health complications of consuming excess isolated fructose in a calorie-appropriate diet.
Yes, fruit contains fructose. Yes, pure, isolated fructose has been shown to contribute excess calories in the diet, which leads to weight gain. High fructose corn syrup (or “corn sugar” as it is now called) is absolutely not healthy. However, there is no pure, isolated fructose in green smoothies and fresh fruit. Instead of isolated sugar (like if you drank a can of soda pop), green smoothies contain vitamins, minerals, antioxidants, phytonutrients, fiber, protein and fat.
You do not need to worry that the fructose in green smoothies will make you fat. It won’t.
Every published health study that I have read is based on pure, isolated fructose in sweetened beverages or injected into the blood stream. Green smoothies are ingested with the fiber, vitamins, minerals, protein, fat, antioxidants and all the other good stuff that high fructose corn syrup and isolated, crystaline fructose lacks.
Not a single legitimate scientific or medical organization would recommend a reduction or restriction of fruit intake because of its fructose content. The only “fruit restriction recommendations” come from alarmist, fringe websites on the Internet or from “rogue doctors” with questionable credentials who peddle all sorts of pseudoscience.
And one last thing I’ll say about fructose in fruit – it is silly to worry about isolated nutrients in whole foods. If you really wanted to avoid all foods that had anti-nutrients or potentially harmful organic chemical compounds in it, you would starve to death. EVERY single piece of food you eat – including organic, bio-dynamic, harvested by your own hands – contains anti-nutrients and things that can harm you IF you extracted those compounds from the whole food and consumed it in excess.
Green smoothies and fruit are a whole foods. Fructose is not. Yes, there is fructose in green smoothies and whole fruit. No, the fructose content of whole foods will not harm you or cause weight gain or diabetes.
Read more about why I don’t have any low sugar or low fructose green smoothie recipes on my website.
Green Smoothies Will Rot Your Teeth
Actually, green smoothies will not rot your teeth, nor will they directly contribute to tooth decay and cavities unless you have poor dental hygiene. I have had a daily green smoothie since January 2008. In fact, I drink two large green smoothies every single day. And I eat way more fruit on a daily basis than the average person eats in a week.
I shouldn’t have any teeth left, right? I have never had problems with my teeth since drinking green smoothies. In fact, my most recent dental checkup showed strong, healthy teeth and no excessive enamel wear.
I’ve covered this controversy in much more detail here.
Destruction Of Nutrients
There is no evidence to back up the claim that blending green smoothies in a blender destroys up to 92% of nutrients.
If that were true, I would be severely malnourished after five years of drinking them every day. None of the many green smoothie testimonials on my website would have been written. The reasoning behind this claim is flawed and over-simplistic.
Blending vs. Chewing
Another controversy is the whole blending vs. chewing argument. Chewing releases saliva and digestive enzymes. It’s the first step in the digestive process. However, that doesn’t mean that drinking a green smoothie will hinder proper digestion.
Saliva is still released as you drink a green smoothie. In fact, you’ll probably start salivating as you chop the ingredients and add them to your blender. I usually snack on bits of fruit and even greens as I make my smoothie. This helps rev up the digestive engine.
When I sip a green smoothie, I let each sip mix with saliva while I savor the delicious flavor. You can, if you want, “chew” your smoothie (be sure to brush your teeth afterward).
Some people are concerned that drinking green smoothies can cause the jaw to atrophy and weaken. I find this fear to be unfounded. Humans have jaws that are significantly atrophied compared to our closest primate relatives. This is a product of our evolution due to adaptations to processing foods that require less chewing (and consume less energy to digest). Humans simply do not have the jaw power, size and shape to keep up with the grazing power of a chimpanzee. And we don’t need to.
Besides, your jaw isn’t going to atrophy by drinking one or two green smoothies per day. It’s important to eat solid, whole foods in addition to green smoothies.
As far as digestion is concerned, green smoothies are very easy to digest because they’ve been thoroughly blended (or mechanically chewed, you could say). If anything, a blended smoothie will digest more efficiently than chewed whole fruits. It’s still entering your mouth, mixing with saliva and entering your stomach naturally.
Green Smoothies For People With Health Conditions
My green smoothie recommendations and recipes are geared for healthy people with no pre-existing health conditions. I cannot possibly share smoothie recipes that are appropriate for all people, regardless of illness, metabolism, age, diet, genetics, etc…
If you have a diagnosed health condition and you are wondering whether or not green smoothies should be a part of your diet, or if they might cause harm, then you should discuss your concerns with a doctor or registered dietician. Explain your goal (more fruits and vegetables, especially greens, in the diet) and establish some dietary guidelines for fruits and smoothies that are appropriate for your unique medical circumstances.
Countless scientific health studies indicate that an increase of fruits and vegetables in the diet is associated with a reduced risk of many chronic diseases. There is a lot of research associating an increase of fruits and vegetables in the diet with a reduction of symptoms and lower severity of certain diseases and medical conditions. Fruits, vegetables and green smoothies are your friends, not your enemies.
But if you have a medical condition, or a metabolic disorder, then you need to work with your doctor or nutritionist.
People with hypothyroidism may need to restrict their consumption of cruciferous vegetables like kale and broccoli. People who are prone to kidney stone formation may need to steer clear of high-oxalate foods like spinach. Those with diabetes may need to half some of my recipes, or choose lower sugar berries over higher-sugar bananas, mangoes and grapes.
However, if you do not have any pre-existing medical conditions, then you do not have to worry about raw kale causing hypothyroidism or oxalates in spinach causing kidney stones or the fructose in fruit causing diabetes.
Should Green Smoothies Contain Mostly Fruits Or Mostly Vegetables?
And finally, let’s address one last controversy about green smoothies. Should you make them with mostly fruits? Or should you add a little bit of fruit and stuff a ton of green in there?
In general, my green smoothies contain 60% fruit and 40% greens by volume. My typical 32-ounce meal replacement green smoothie will contain about 300-400 calories (men will probably be more satisfied with a 500-calorie green smoothie – about 4 pieces of fruit – banana, mango, apple and orange) and an entire head of romaine lettuce (or four cups of other leafy green). Adding this much fruit provides the calories to make this smoothie a meal.
A vegetable-based smoothie will not provide sufficient calories to be a meal replacement smoothie. Even if you made a 32-ounce smoothie with just one apple, 1/2 cup blueberries, and a ton of vegetables and greens, you won’t come anywhere close to 400 calories. You’d be lucky to get 200 calories.
The problem with this is that you might still feel full from the fiber, but you risk under-consuming calories, especially if you follow a raw food or whole foods diet. Getting too few calories will sabotage weight loss and lead to nutrient deficiencies and health problems.
In short, fruit-based green smoothies can replace meals and are effective for weight loss.
Vegetable-based smoothies are too low in calories to be considered meals, so they are better used to supplement a calorie-sufficient whole foods diet between meals or consumed with meals – if you wish to do so.
Unless you are physically bothered by fruity green smoothies, I don’t think you need to worry about restricting fruit (or green smoothie intake). If you are concerned about sugar, look into other areas of your diet first. Cut out all refined sweeteners, soda/pop, fruit juice, white rice and white bread. Green smoothies should replace unhealthy foods.
I can’t think of any other subject that has more controversy than nutrition and diet. You can save yourself the headache, confusion, and worry, by simply focusing on a calorie-sufficient, whole foods diet and periodically checking to make sure you are getting sufficient nutrients (I use Cron-o-Meter for this purpose).
I’m done with nitpicking foods and getting caught up in isolated nutrient controversies. Eating food shouldn’t cause anxiety, frustration and fear. I lost 40 pounds with green smoothies, and many of my readers lost anywhere from 20-100+ pounds while dramatically improving their health. So drink up your fruity green smoothie, watch the weight come off and enjoy your life!
Tracy Russell is the creator of RESET 28: A 28-Day Program For Energy, Weight Loss & A Healthy Glow, and founder of Incredible Smoothies. She has been helping people take control of their health and well being with green smoothies, a whole foods diet, and fitness since 2009.