Searching for a 7 day detox plan? Why they're counter-intuitive and damaging for your health

You read that right - fad detox diets can damage your health and lead to weight gain in the long run, confirm the pros.

A woman drinking a green smoothie on a 7 day detox

You read that right - fad detox diets can damage your health and lead to weight gain in the long run, confirm the pros.

So, you're searching the Internet for a 7 day detox. Perhaps you got back from holiday and felt you ate too much, or have been so busy you haven't been eating as many nutrient-dense meals as usual.

Public service announcement: you do not need to detox, starve yourself, or eat less just because you've been enjoying your life.

It can feel suffocating at times - especially in a society where pressure to eat a certain way, drink a certain way, or try every celebrity workout under the sun is still at an all-time high. That said, all that really matters is working out what healthy living looks like for you and your body.

Keep scrolling to read why a 7 day detox, if you have been considering one, may actually do you more harm than good.

7 day detox: why a dietician maintains they're actually bad for your body

What is a 7 day detox? 

As per the NHS website and dietician Amanda Johnson, detox has long been a popular buzzword and focuses around the idea that, after eating particular foods, you need to "cleanse" your body of certain toxins or chemicals.

Nutritional therapist Chris Barker of The Lifestyle Clinic continues that, while detox originally meant medically supervised withdrawal from drugs or alcohol abuse, somewhere along the line, it transitioned into a term used by the wellness industry. In his opinion, most detox programmes are more focused on preying on your insecurities and making you pay large sums of money for wonder teas, weight loss guides and so on, rather than preaching the things that genuinely boost your health, like drinking more water and moving mindfully.

Detoxes normally promise to cleanse the organs of "bad" toxins and will encourage you to entirely avoid a combination of food groups like:

  • Alcohol
  • Milk
  • Dairy
  • Coffee
  • Carbs

They'll also likely advocate things like fasting, "kickstarting your metabolism", overexercising, raw foods, and so on.

But it's all a myth, Johnson shares - especially the part about toxins. "If the human body really accumulated lots of toxins, then you would feel ill," she explains. "The concept of detox diets is irrational and unscientific. In actual fact, when you starve your body of calories your body will ultimately start to build up chemicals called ketones which can result in nausea, dehydration, weakness, light-headedness and irritability."

Barker agrees, adding that, fun fact: the body already detoxes itself each and every day. "There are hundreds if not thousands of strange and dangerous detox solutions online," he explains.

Take, for example, the so-called master cleanse, which asks you to abstain from all food for fourteen days and drink a minimum of six to twelve glasses of filtered water, lemon, cayenne pepper, and two tablespoons of maple syrup a day. "While you aren’t eating any nutritious food, you will have drunk approximately 200 to 300 grams of sugar per day (the WHO recommends around 25g of sugar a day)," he points out.

Many yellow fruits and vegetables on a yellow background.

Why can a 7 day detox be bad for you? 

Not to mention the fact that, by excluding certain food groups from your diet, such as protein, dairy, wheat and so on, you run the risk of depriving your body of the essential nutrients it needs to survive. "The reality is that these foods provide us with important nutrients and it's unnecessary and potentially harmful to exclude them from your diet," she continues.

Similarly, if you do drastically reduce your calorie intake all of a sudden (the recommended daily calorie target for women is 2000, as per the NHS, and some detoxes recommend an intake of anything from 500 to 800 calories) you're at risk of your body being so desperate for energy to function, you binge.

Woman blending a smoothie for a 7 day detox

(Image credit: Getty Images/Tetra images RF)

While upping your intake of fruit and veg will only ever bring health benefits (hello, fibre) - you don't need to go overboard and only eat fruit and veg. A good way of looking at it: during one Marie Claire UK Decoded Instagram live, Doctor Megan Rossi, aka the Gut Health Doctor, recommended focusing on what you can add to your plate - aka, what new fruits, vegetables, nuts, seeds, legumes or ferments you can try - rather than what you should be taking away.

Health should never be about deprivation - rather, tapping into your body's innate hunger signals and feeding it the food that makes you feel good. 

Like any fad diet, a 7 day detox is just another way of starving your body and losing water weight that you'll, more likely than not, simply put back on.

Think of it this way - as Barker puts it, you are already equipped with the best detox equipment out there, your own body. "You see, your body is designed to deal with an influx of toxins, both exogenous (external) and endogenous (internal)", he shares. "It's an amazing machine that runs its own natural detoxification process 24/7 in order to help keep you alive."

So, if you're keen to help your body run at max capacity, focusing on building healthy lifestyle habits which support you even when you've had a few late nights and 100% fried meals is key,

Things like:

  • Drinking enough water every day
  • Practicing meditation or mindfulness
  • Eating three balanced meals every day with a balance of protein, fats, carbs and vegetables.
  • Moving in whatever way feels good to you, be that walking, stretching, running or something else
  • Breathwork training

Can all help - but remember, if you don't enjoy any of the above, don't force it. A healthy lifestyle isn't healthy if you don't enjoy it, after all.

Struggling to foster any healthy habits that you genuinely enjoy? Our guide to reframing negative thoughts might help. Similarly, heading to a new gym class or joining a local run club, where the sport is a social event rather than a pressured workout, could be for you.

On that note: remember that looking after your mind is as important as looking after your body. After all, you could do all the detoxes in the world but if you're still not mentally happy, you won't feel great. Practicing regular self care and being kind to both your body and mind is key here, and we reckon our guide to self care ideas is a good one to bookmark for later. Bubble bath, anyone?

Freshly made smoothies poured into glasses.

(Image credit: Getty Images)

"I tried a 7 day detox - it was hell"

Louise*, 27 from Bournemouth, shares why she'd never recommend a 7 day detox plan after following one herself.

" I first tried a 7 day detox when I was about 18 years old - I was desperate to fit into a dress for our end of year uni formal."

"I was eating minimal meals a day and, while I got through the first one okay, I soon became addicted to the feeling of losing weight, practicing the detox more often than eating normally. I had no energy, suffered from constant headaches, and was grumpy all the time. I also lost my periods as I wasn't giving my body the nutrients that it needed."

"Now, eight years on, I have a healthy relationship with food and see how ridiculous it was to put my body into such a severe calorie deficit. I'm grateful that it didn't cause more long-term damage and can't imagine how I functioned with so little energy all the time. Focusing on building genuinely healthy habits into my day-to-day rather than grasping at the latest quick-fix diet has changed my life - I'm now happy and genuinely healthy, too."

Ally Head
Senior Health, Sustainability and Relationships Editor

Ally Head is Marie Claire UK's Senior Health, Sustainability, and Relationships Editor, nine-time marathoner, and Boston Qualifying runner. Day-to-day, she works across site strategy, features, and e-commerce, reporting on the latest health updates, writing the must-read health and wellness content, and rounding up the genuinely sustainable and squat-proof gym leggings worth *adding to basket*. She's won a BSME for her sustainability work, regularly hosts panels and presents for events like the Sustainability Awards, and is a stickler for a strong stat, too, seeing over nine million total impressions on the January 2023 Wellness Issue she oversaw. Follow Ally on Instagram for more or get in touch.