

Who needs to detox or crash diet? Welcome to my episode three recap of Diet Secrets and How to Lose Weight which is all about crash dieting and detoxes this time around.
This four part Channel 5 series asked a group of experts common questions about dieting to divine fact from fiction. As ever, I watched with my personal finance cap on to see how their views might influence our spending for the better.This Channel 5 weight loss programme says in the intro that they investigate “the surest way to be the size you’ve always wanted to be.” I think it’s probably impossible to make yourself an imagined size, but many of us will lose our paycheque trying.
The show pitches itself as the truth about diets and how to succeed at losing weight. To that end, doctors, nutritionists and researchers tackle trendy health claims or popular myths in each episode. I didn’t want to misquote anyone, so I’ve tried to faithfully capture their opinions below. It’s not a word for word transcript, but I’ve tried really hard not to change anyone’s meaning. I hope this information is demystifying so that that we can stop wasting money on pseudoscience.
Here’s what I’ve covered below:
Are Crash Diets Effective For Short-term Weight Loss?
Are Fasting Diets Effective For Weight Loss?
Can A Crash Diet Of Less Than 800 Calories Per Day Reverse Type 2 Diabetes?
Can You Detox With A Diet?
Do Crash Diets Make You Put On Weight In The Long Term?
Diet Test – The 5:2 Diet
Diets From Hell #3: When Enough is Never Enough
What Does It All Mean For Our Wallets
The diet industry makes billions from crash diets and I’m not convinced they’re great value for money. Contrary to some, I think that a goal to get fitter or eat more nutritiously is not only possible while saving for something big like a house deposit, but can actually be a way to spend better and achieve that very savings goal.
Missed the series so far?
If you missed it, here’s the episode one recap all about fats in food.
Episode two was all about superfoods.
I am NOT a doctor, nutritionist etc and I rely on professionals like the ones in this programme to be my Yoda, my Giles, my Deaton [insert name here of your favourite wise fictional character]. I am not trying to give medical advice, and I don’t think bloggers should make any claims without referring clearly to experts and evidence.
Here’s the experts featured in the series:
Dr Ranjan Chattergee GP
Dr Linia Patel, Consultant Dietitian
Pixie Turner a.k.a Plant-based Pixie
Dr Gavin Sandercock, Director of Research at Essex University
Nutritional Therapist Ian Marber
Science Journalist Nathan Rao
Rosemary Conley OBE
Dr Nicola Guess, Assistant Professor at Kings College London
Dietitan Priya Tew
Clinical psychologist Dr Anna Colton
Dietitian Sian Porter
Professor Mark Thomas, University College London
Judy Swift, Associate Professor of Behavioural Nutrition
Dr Sarah Schenker
Dr Aseem Malhotra, Consultant Cardiologist
Dr David Unwin GP
I’ve just used first names below after introducing someone to make things easier, but also because I like to think I’m on first name terms with everyone after about five minutes of basking in their knowledge. This applies if they already appeared in the previous episodes first too.
Let me know in the comments if any of this helps you think about food more positively, and what you do to save on food spending normally.
Episode 3 – Crash Diet Or Detox?
How about neither?
The appeal of crash diets relies on instant gratification. Because they theoretically knock a few pounds of rickety tick, the nation gravitates towards them for the quick results. [If you learn to delay gratification when spending, I hope it has a knock-on effect!]
Question #1 Are Crash Diets Effective For Short-term Weight Loss?
Anna says the NHS guide for calories for men and women is general anyway because your height and other factors affect how many calories you need.
Pixie says crash diets can make you lose weight fast; that doesn’t make it healthy.
Nathan says most of the weight you lose at first is water.
Linia says you could just be burning muscle.
The final word: 73% of the experts said crash diets were effective for short-term weight loss, 20% said they weren’t and 7% said they agreed with neither.

Question #2 Are Fasting Diets Effective For Weight Loss?
One theory is that fasting works because it limits the opportunities to eat, plus you can eat what you want on non-fast days. However, potentially eating everything under the sun on non-fast days destroys the fast overall.
Aseem says you should also eat good quality food on non-fast days.
75% of the experts said yes, 6% said no, and 19% said neither.
Frankie Essex tested a fasting diet for them in the same ep and I’ve recapped that below.
Question #3 Can A Crash Diet Of Less Than 800 Calories Per Day Reverse Type 2 Diabetes?
Type 2 diabetes is on the rise, but calorie restriction such as Dr Michael Mosley’s The Fast 800 fix this?
Ian says research suggests that low calorie diets can reverse type 2 diabetes in the very low stages.
Nathan says if you reduce calories, you likely reduce sugar also therefore managing the diabetes. He hasn’t seen enough evidence to say it reverses diabetes.
Anna says it’s very hard to sustain a low calorie diet though.
Pixie says after the eight weeks of Michael Mosley’s diet, she thinks you will go back to eating as you did.
The final word: 43% of the experts said type 2 diabetes can be reversed with a crash diet of less than 800 calories. 29% answered no, and 28% were unsure.
Question #4 Can You Detox With A Diet?
Sian says nope.
Ian says your body detoxifies itself.
Pixie says these are a marketing scam. Livers and kidneys detox you. Drinking lemon water doesn’t wake up your liver because if your liver goes to sleep, that means you’ve died. We have teeth, so why would you juice?
Anna says juicing loses all the fibre and gives you concentrated sugar, so it can’t be a detox. The lemonade diet will make you unwell eventually (it’s a “detox” drink of lemon, maple syrup, and cayenne).
Pixie says the heat from chilli is just heat from a chilli, it’s not an indication that you’re burning more calories.
Sian says the halo effect is likely responsible if anyone feels better after a detox: when we diet we tend to do other supportive things like trying to get more sleep, going teetotal etc. It’s not necessarily the diet that makes anyone feel better.
The final word: Only 7% of the experts said we can detox with a diet, 80% said no, and 13% were unsure.

Priya also says fasting is not suitable for anyone who has had an eating disorder. How many promoters of fasting point this out? (Michael Mosley’s website does mention it in their disclaimer).
Question #5 Do Crash Diets Make You Put On Weight In The Long Term?
Anna and Nathan both say they’re not sustainable…
Ian agrees because you abandon your social life for the diet.
Anna says they don’t retrain the brain, so you go back to old eating habits.
Aseem says there is plenty of data that crash dieters end up heavier in the end.
Priya says when you regain weight, there is a tendency to put on more than you started with.
The final word: 80% of the experts said yes, 7% said no, and 13% said neither.
Diet From Hell #3: When Enough Is Never Enough
Bullies targeted Hannah at school for her weight. She started dieting with some success, but then met her future husband and they enjoyed takeaways and junk food together. She lost weight for her wedding however.
Hannah didn’t stop there though, eventually losing 10 stone. Her husband wanted her to still eat fast food, so she would leave the room rather than be goaded.
Ultimately, Hannah needed medical intervention and her marriage disintegrated. Her doctor reintroduced carbs and specified special drinks to regain weight, and she went for weekly weigh-ins to avoid being referred for an eating disorder…
I guess the question is, when is enough enough? This reminds me of another show where they interviewed a weight lifter. She built muscle as an alternative to her previous approach where she would only eat 800 calories a day and not exercise. She realised in that mode of thinking that she would always want to be thinner for its own sake, and that there was no way to eat less than she already was without needing intervention. When the aim is always eating less to be skinny just because, there is no stopping point (except death).
A goal to build muscle means you MUST eat to fuel that muscle growth. Muscles waste as we age also, so developing a strength training habit sooner rather than later should shield against falls and mobility problems in later life.
More about that here:
How To Get Fit Fast (For Free) Recap
Diet Test: The 5:2 Diet
Frankie Essex tested this fasting diet for them with her GP’s approval. Westminster University found her weight and visceral fat were within normal range and her BMI was a little high. Unlike the previous ep, they decided to go ahead with the diet despite declaring the other measures normal.
The 5:2 is calorie restricted and besides intermittent fasting, she also couldn’t eat chocolate, sweets, white rice/bread/pasta, potatoes, or drink fizzy drinks and alcohol. That’s for starters (just not the kind of starters you eat…) There are other exclusions too!
This is because for the five days when she was not fasting, she was only meant to be eating Meditteranean-style.
Frankie had released weight loss DVDs before this. Her mum died while she was young, so she relied on ready meals growing up and could eat whatever she wanted without her mother’s influence. Like Josie and Bianca in the previous two episode she’s also been bullied for her weight in the media.

The verdict
Frankie’s fast day meal was only 400 calories, but included smoked salmon, avocado, rocket and spinach (nom!). Her friend came round and ate fish and chips next to her because good friends are meant to sabotage you…(No, wait…That doesn’t sound right…That sentence is broken on several levels).
The next time her friends visited she made them a salmon meal to counter this, but accidentally doubled the calories by adding hollandaise.
She found it harder as time went on as she had a Chinese takeaway (with friends…Most diets don’t really prescribe what to do about social eating). Ian raised this point above in his answer to question #5.
At the end the University found she lost weight and 4cm from her waist to hip ratio. Her fat mass went up, but by such a small amount that they thought it might be a daily variation. Frankie wanted to carry on, but also found “temptation” hard to resist. Hm, doesn’t sound like a sustainable lifestyle therefore…
What Does This All Mean For Our Wallet?
Crash diets carry risks and sound like they are also a waste of money if you end up potentially just losing muscle, water weight, and putting everything back on the week after.
It sounds like a long term approach to eating nutritiously would be better for our health and finances.
No one gains healthwise or financially from fasting if they have a blowout on the non-fast days…especially if they feel guilty as a result.
The majority of the experts were against any so-called detox, so best to swerve pricey detox drinks and schemes.
Talk to your doctor if you’re unsure about anything (that will be “free” for most of us).
I do write plenty of the blog for my own edification and entertainment, but please do let me know your tips in the comments if you’re a professional with more to add. Or please shout me if any of this has helped you save money without sacrificing your health.
Next on Diet Secrets and How to Lose Weight…
In episode four expect the following:
What are carbs?
Are there good and bad carbs?
Are carbs making us fat?
Is sugar addictive?
Are carbs necessary for physical performance?
Do we need carbs for concentration and mental aptitude?
Diet Test: The Sugar Free Diet
Diets From Hell #4: When Gastric Bands Attack
Here are the links again to the previous episodes if you want to go back:
Episode One (Fats)
Episode Two (Superfoods)
I also recapped Save Money Good Health and part two‘s round up of the “cheapest diets” was about crash dieting also.
I’m also going to recap The Big Fat Lies About Diet and Exercise eventually. That was a Channel 5 diet programme from 2019 that matches up with this and features a lot of the same voices. The mailing list is ready and waiting for you if you want to know ASAP about anything new on the blog, plus I send out extra savings tips in the weekly emails.
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