Weight loss is probably the most popular reason people start juicing. However there’s an inconvenient truth about the verified facts around juicing and weight loss:
There is nothing……and I do mean nothing…….that’s proven juicing or juice fasting to be effective.
I don’t mean there have been studies or observations that have shown that it doesn’t work. I mean there’s simply nothing.
Take a look at the results that you get when you do a search on PubMed for the relationship between juicing and weight loss:
Zilch.
And here’s a search on Google Scholar:
All we really have to go by is the legend of Joe Cross.
The Slightly More Subjective Truth
So we know there’s no ringing endorsement from the formal medical sciences about juicing and juice fasting for weight loss. (Note: this means your bullshit detector should go off anytime you read about a juicing diet that begins with words “science has shown that….”).
However, this isn’t reason for dour pessimism. Consider the following:
- It is better to have no formal evidence than formal evidence showing that something doesn’t work
- Medical studies that study aggregates of complex phenomena can have limited value
- Despite the lack of formal evidence, there are a lot of good reasons to assume that juicing is very very good for you
- Practices that are very very good for you tend to help you maintain a healthy body weight since a healthy body weight naturally follows a well functioning metabolic system
- On a personal level I know myself and several other people have benefited greatly from making juicing a regular habit
What Happens When You Juice
When you juice you’re giving your body a condensed money shot of essential nutrients in a highly available form that gets quickly absorbed into your body.
This helps in the following ways:
- Hunger is partially due to your body missing nutrients
- Energy levels are partially due to your body missing nutrients
- Nutrient dense fasting is extremely good for you……including weight loss
Concerning the latter point, your body goes through similar physiological changes when it fasts as it does through extreme exercise. Our endocrine systems are rigged to thrive on scarcity.
So all isn’t lost. It’s common sense that juicing is really good for you. The kerfluffle comes when you try to deliberately channel it towards weight loss in a short period of time.
Juicing vs Juice Fasting
For beginners there’s a big difference between juicing and going on a juice fast. Too many people try juice fasts first and start juicing afterwards Juice fasts are messy and easy to screw up.
Despite the health benefits of fasting, I’ve never considered it a good idea for out of shape people to go on them cold turkey. It’s similar to out of shape people trying to do too much at the gym who end up injuring themselves as a result. A juice fast has the most beneficial effect on someone who’s already accustomed to healthy food. Your body will respond best to a fast if it’s already been primed to expect nutritious food. If it hasn’t been acclimated then it might respond in unpredictable ways and maybe even return to a previoius metabolic stasis if it doesn’t have reason to think the change in diet will be permanent.
Some mention the need to detoxify their body quickly, but this reasoning is flawed. Your body is always in a state of detoxification, and it’s very difficult to speed up those processes in a matter of days by simply changing the food you eat. It’ll probably just counteract the new changes so it can stay at what it thinks is normal. And that’s when things can get really messed up.
I’ve written before about the benefits of starting slow when it comes to juicing, and nothing in my own experience has changed my mind. Juicing as a routine is extremely benign and almost incapable of causing harm. It’ll have the greatest effects on people who have poor diets. Juicing as an all out fast is a bit dicey with lots of impediments to successful completion, particularly for people with no experience with this kind of diet.
So when it comes to fasting, it’s best to think of it as a way to give your body a healthy shock to spruce up its metabolic system, but it’s not a good way to quickly spot reduce some pounds. Take heed.
Health Kismet Blog 
Jonathon, you are full of studies until you come to the subject of juicing and claim that “it’s better to have no formal evidence than evidence that something does not work” Well, yes, when you are trying to prove something like juicing is a good thing. If you have nothing saying it is good OR bad than we should assume that it is good for you? You should know better, pure fruit juice, with all its fructose and none of its fiber, hits your liver like a cannon, causing all sorts of problems. Why not suggest whole fruit and vegetable smoothies instead?
LikeLike
Heather,
I’ve written before that the benefits of juicing mimic the benefits of nutrient dense caloric restriction and given studies that say just as much. Whole fruit and vegetable smoothies work just as well too. I’ve touched on fructose, but the drawbacks of fructose when they’re only consumed from fruits are not really there IMO, they mostly come from HFCS.
I’ve also written that published research is not the gospel, and many, if not most of them are flawed due to small sample sizes the bias towards “publishable” results, and it’s okay to use self experimentation when appropriate to come to your own conclusions if there’s nothing in its place.
LikeLike
I’ve been reading a lot of your posts and yes I love the way you write, very clear and straight to the point. Like you, I never considered fasting and extreme exercise as a good idea to be physically fit and in shape too. Why fast when we can actually discipline ourselves to have a balance diet and proper exercise. I see that juicing is a good idea but I would definitely not go fast with it. I still prefer to eat real food I mean not in liquid form it’s more satisfying.
LikeLike