Is a Green Smoothie Diet or Juice Fast Healthy?

I frequently get asked the question about whether or not a green smoothie diet is healthy and how long one should go on such a diet to lose weight or to cleanse.

Another question I get a lot concerns juice fasts.

I’ll start off by talking about juice fasts, then I’ll get to smoothie diets.

Juice Fasting Is Not Healthy

There, I said it. Juice fasting for more than a few days just isn’t good for your body. Juice fasting for even one day is completely unnecessary.

I realize that there is a lot of debate on the topic of juice fasts. On one side, you have those praising the benefits of juice fasting (such as detoxification, weight loss, feelings of lightness, “spiritual awakening”).

On the other side, opponents of juice fasting claim that frequent or long-term (30+ day) fasts disrupt metabolism and can lead to nutrient-deficiencies.

Juice fasting is working against your body. It’s working against cleansing (because there’s no cleansing fiber in juice). It’s working against weight loss (because what happens when you end your juice fast? You guessed it, the weight comes right back on!)

Read more about why I do not recommend juice fasts for weight loss and detox.

What About A Green Smoothie-Only Diet (AKA Green Smoothie “Fast”)

I regularly drink meal-replacement green smoothies. For me, it’s a convenience thing. I’m not trying to lose weight or detox. It’s just really quick and simple to blend up a 32-ounce green smoothie for breakfast.

However, I would never, ever do (nor advocate) a green smoothie-only diet for a couple reasons.

First of all, many green smoothies are too low in calories to be considered a meal. Anything under 300 calories per meal is starvation.

If you were to drink a green smoothie only-diet, you’d have to make epic green smoothies. Your 40+ ounce monsters would have to contain at least 533 calories apiece if you ate three times per day and needed 1600 calories to maintain (or lose) weight.

Not many people can comfortably chug 120-150 ounces of green smoothie per day, every day. If you are drinking a 16-ounce green smoothie, you’re probably only getting about 200 or so calories, maybe even less. Drinking 16-ounce green smoothies in place of meals could set you up for a serious calorie deficit and nutritional deficiencies very quickly.

Unless you are willing and able to drink a 40+ ounce green smoothie three to four times per day AND pack each smoothie full of sweet fruit (I’m talking 4 bananas, 1 mango, a few tangerines AND a handful of red grapes with an entire LARGE head of romaine lettuce), then you will not get enough calories and nutrients to stick to this diet and maintain your health.

Go For Long-Term Change vs. Short Term Shock Diets

Secondly, the other reason I don’t advocate a smoothie-only diet is because I don’t believe in temporary diets. If you want ultimate health and long-term results, you need to make long-term, permanent diet and lifestyle changes. If you return to old eating habits after the smoothie diet ends, the diet was completely ineffective.

This is why I don’t advocate green smoothie diets, severe calorie-restriction, juice or water fasts or any other temporary diet. Temporary changes simply do not lead to lasting results. Doing a smoothie diet or juice fast a few times each year does absolutely nothing to help you lose weight or detox if the rest of your diet is not in order.

You might get short term benefits with a short term green smoothie diet that meets your nutrition targets, but it is far better and far more effective to implement green smoothies on a daily basis as part of an overall diet and lifestyle plan.

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.