Juice detoxes explained: why they’re crap and why they only seem to work

The term detox (or cleanse) is a bit misleading. 

It implies that our bodies are intoxicated, poisoned, and they’re not. If they were, that level of toxins would determine major functions in our body to shut down.

A toxin is a substance that is poisonous to humans. So if you’d need a real detox because you’re poisoned, trust me, you’d know it. 

Most people think about toxins in food being sugar, grilled meat, or any kind of meat, animal products, hormones and such, that don’t have a proven poisoning effect on the human body. It’s not to say they are healthy, but they’re not poisonous either.

In this category we also include pesticides, heavy metals, pollutants and similar substances that are obviously harmful for our health.

So are other substances (found in food) that we consume in excess but that means immensely huge doses that very few people can achieve. So, no, having fish (even daily) will not cause you a mercury intoxication unless you eat tons of it. The dose makes the poison.

So why the craze about juice cleanses?

An experienced fitness pro or serious food coach is very unlikely to recommend juice only diets or cleanses to everyone, except for some cases when there are some health issues.

That’s why the first time I heard a very knowledgeable trainer say he does a few days of juices every year, I was really surprised. Then it all made sense when he said he does this after the holidays, when he’s had too much food, meat, sugar and so on.

Two or three days of juices, in this case, are just a way of giving his body a break and helping his digestion (getting out all the intestinal matter).

However, this – and he agreed – can be achieved with solid foods as well. There’s no difference in the benefits you’ll get between a few days of drinking juices and the same number of days of going on a plant based whole foods diet. Actually, the second option is higher in fibre and you’ll be less hungry and less sluggish.

The thing is that we see a lot of famous people that seem to look good and be healthy, promoting these cleanses (and other radical diet fads) and we trust them. If they say it works, then it’s true, right?


The craze perpetuates because people believe they do lose weight. And you might see a difference on the scale, but it’s not fat that you lose.

First, you lose some weight that is just intestinal content. And then you just lose water (as your muscular glycogen, that retains water, is depleted). Fat is smarter than that.

But you also have less energy so you move less, because you’re feeling tired. You might skip the gym while on a juice detox, walk less, take the elevator more. This decreases the NEAT (non exercise activity thermogenesis) aka the calories that we burn from all the other activities we do besides working out.

Also, your body will burn less calories due to a decreased digestion function. Part of the daily energy expenditure is this thermic effect of food – the energy our body uses to digest food.

If we give it juices, there’s nothing left to digest, so those calories will stay with us.

So, in conclusion, there’s nothing magical about all those kale cleanses, beet juices, and laxatives. 

If you lose weight it’s because you empty your stomach and lose some muscle glycogen and if you feel better it’s because there are more veggies in your menu and no more popcorn and chips.

How our body detoxes

Let’s take a trip down the memory lane, when we were kids and learned about the way our bodies detox. 

Remember that lesson or did you skip the class? You might recall that the liver, kidneys, lungs and skin are the main organs that help us take the bad or unnecessary stuff out. A mix of lemon and ginger on an empty stomach doesn’t make that much sense in this context anymore, right?

Sure, you might enjoy a ginger lemonade, but don’t call it a detox.

Nothing that claims to take out the toxins or promote fat loss is worth buying.

So what should I do?

Well, you can start by giving your body a break. Deloading. Cutting the unnecessary processed foods, stress, alcohol. Maybe even eating just a bit less. 

Instead of focusing on adding something – like those kale juices I mentioned, focus on cutting the bad stuff from your diet. Just keep a food diary for a few days and I’m sure you’ll be able to tell what the traps are.

You don’t have to restrict completely, just reduce: fried foods, fast food, processed foods, sauces and dressings, alcohol.

You can also try:

A vegan diet, for a while.

A vegetarian diet, for a while.

Adding cruciferous vegetables (broccoli and cauliflower, for example) to your menu helps the liver

Excluding alcohol, caffeine, processed foods, added sugar, as mentioned above.

Excluding chemicals – “cleaner” skin products, home cleaning products.

Taking a break from supplements for a while.

Getting away from toxic environments: stressful environments, people, notifications, apps, Insta and Facebook.

All these will give your liver some rest and let it perform its detox functions to the maximum.

And if you want to add something, make it some extra veggies.

If your goal is also fat loss, you can also take a look at hyper caloric stuff such as raw vegan cakes (a-ha!) and nut snacks, huge quantities of cheese or other foods that you just can’t stop eating.

But I’ve spent a small fortune on some colorful juices. What do I do with them?

Sure, go ahead and try them out if you want. 

It’s your call if you only want to have juices for 1 or 2 days, and then start adding solid food. But the effort will be quite big, in my opinion, and the result will only be some temporary weight loss that is actually – as I explained – a loss of water, intestinal content, and, if you stay on juices for more days and don’t exercise, some muscle as well.

Look, I’m not saying you should give up juices, lemon water or kale if you enjoy them. But don’t rely on any magical ingredient to fix a problem that:

1 – you don’t even have,
2 – your body can already handle,
and 3 – has zero effects compared to what you can achieve by “cleaning” what you are already eating.

Be careful with the sugar content

Most of these juices have a sky high sugar content. Carrots, beets, fruit. And it’s simple sugars, not to mention that the fibre (that magical stuff that actually helps your digestion) has been juiced out. Ironic you should want to avoid fibre while on a detox, right?

Also, keep in mind that it’s also a form of restriction. And usually, restriction is followed by compensatory behaviours such as overeating, binge sessions, guilt, disordered eating issues and poor body image – you don’t want to go there.

The good parts of a juice detox

You know I’m optimistic by nature. I’m trying to see the glass half full in the entire detox thing. Which is, in my opinion, the fact that you are considering a lifestyle change and a menu change. 

Unfortunately all detoxes and cleanses are seen as a temporary effort, 3-7-10-14 days, after which you go back to burgers and fries. 

But it can also be your first experiment with eating differently, better, cleaner. And if a few days on juices is what you need to guide you on this new path, then do it. 

Also, a few days of drinking fruit and vegetable juices means you’ll be getting some vitamins and minerals that you otherwise might not, if you usually don’t eat enough vegetables.

Just remember that, if you go back to your old habits, then it was just a waste of motivation, time, money, not to mention some effects on your body that work completely AGAINST your #feelgoodlookgood goal. And that’s why I’m not usually happy with radical approaches, but I’ll rant more about adherence in another post.

Do you ever do detoxes?

I’ve never tried or at least been tempted to try juice cleanses or detoxes or pills.

However, I’ve had days and weeks of eating mostly plant based, and reducing the added sugar as much as I can. It makes me feel better without a doubt.

Also, as a digital detox, I uninstalled Facebook from my mobile, I leave the thing at home when I go running and if I’m away on some mountain in the weekends I barely touch it (and when I do, it’s to take some photos).

You can read even more about detoxes on Examine.com and Precision Nutrition.

Do you have any other questions about detoxes or cleanses? Have you ever done such a detox?

Let me know in the comments and I’ll happily reply.

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