Experts warn of the dangers of detox diets

After the over-indulgences of the festive season, many of us will resolve to get fit and healthy and to shed those excess kilos with the help of “detox diets”.

Detox diets are no silver bullet for healthy weight-loss, say experts

But is it beneficial – or even necessary – to adopt this type of approach in order to get healthy in the New Year? And are there actually dangers involved in dieting in this way?

Detox diets might be a tempting way to go, with proponents of such regimens suggesting we need to get rid of toxins that can cause poor digestion, fatigue, changes of mood, weight gain and a tendency to get sick more often.

Popular detox diets can involve fasting, drastically reducing our calorie intake, avoidance of whole food groups, or following complex schemes that involve taking nutritional supplements in order to cleanse the body of “toxins” and drop several kilos in a very short space of time.

We asked a number of dietitians and health experts for their view on detoxing in the post-Christmas period, and sought their advice on the best way to lose weight and get healthy in 2010.

Dr Elaine Rush is Professor of Nutrition at Auckland University of Technology comments:

“The liver, the second largest (after the skin) organ is exquisitely designed and filters and screens most of the blood coming from the intestine and either detoxifies or gets rid of foreign and harmful substances. The liver will operate best when an optimal diet is consumed, a healthy weight maintained and daily exercise is undertaken. A healthy liver requires a healthy diet consisting of whole foods from the four food groups and water. There is no such thing as a special “DETOX DIET” and they, and fasting, may be harmful as the function of the body will become unbalanced and toxins may be produced. As Hippocrates, who lived to 83 years of age, said “If we could give every individual the right amount of nourishment and exercise, not too little and not too much, we would have found the safest way to health.” He also said “Walking is man’s best medicine”.

“So… my advice is – don’t get constipated, a papaya or a kiwifruit or two a day, plenty of water when thirsty (rather than water with additives like alcohol and sugar) and a walk outside (for the vitamin D) will help ensure regularity. Cut food into small portions before serving, this allows the opportunity for everyone to have a taste but not be overwhelmed or feel they have to eat to please. Use small plates – go back for seconds only if still hungry. Clean your teeth regularly – this may help take the urge to eat and drink away. If you want your family, friends, your liver and gut to live healthier and longer – share with them whole, unprocessed foods and water and keep them moving!”

Dr Jane Elmslie is a Registered Dietitian at the University of Otago, Christchurch, comments:

“My view is that at best detox diets are a quick fix and represent a very temporary solution to the problem of Christmas weight gain. They may be harmful in people who have diabetes or eating disorders and in growing children, teenagers, pregnant women and older adults. They are not safe for anyone as a long term weight loss strategy because they can cause electrolyte imbalances, muscle as well fat loss and a reduction in metabolic rate.

“It might seem boring, but eating healthily can remove any temptation you may have to try a detox diet in the first place. My best tips are:

1. Don’t get trashed; as well as being a toxin and making you hungry, alcohol contains a lot of calories. By limiting, but not necessarily avoiding alcohol, you are less likely to gain weight and you will be doing your liver a favour.

2. Don’t drink on any empty stomach. You will feel the ill effects more quickly and you are much more likely to overeat.

3. Eat the basics every day (vegetables especially greens, some fresh fruit, some wholegrain breads and cereals, lean meats, fish, chicken, eggs, lentils, etc. and some low fat dairy products).

4. Drink some water every day so that your body doesn’t misinterpret hunger as thirst.

5. Have some treats but don’t eat only treats (high sugar, high fat foods) and don’t eat large portions of these foods.

6. If you feel that you have overeaten don’t beat yourself up, just eat a bit less for a while.

7. Get plenty of exercise. This will help to burn off any excess calories you may have eaten.

Sarah Hanrahan is a Registered Dietitian with the New Zealand Nutrition Foundation, comments:

“It would be good to think there was a magic bullet out there for weight loss but the sad fact is many crash diets and detox diets will leave you worse off in the long run. Following severely restrictive diets for more than a day or two can leave you with potentially serious health issues like headaches, tiredness, digestion problems and dehydration, caused by

upsetting the fluid and electrolyte balance. Having completed a detox, dieters can easily become victims of yo-yo dieting as they are left even more despondent as the extra kilos either reappear or stay stubbornly attached. Furthermore detox diets are unnecessary as we each have our very own highly efficient, built-in detox plant, our gut and liver.

“To maintain long term weight loss you should start by simply eating smaller portions of the foods you already enjoy and making the effort to be more active. Try simple changes like larger servings of fruit and vegetables, aiming to have them take up at least half your plate. Switch to lower fat milk and always have breakfast. Good long term weight loss is around 500g / week. For more information on healthy eating go to,”

Jan Milne, Registered Dietitian and Executive Director of the New Zealand Dietetic Association, comments:

“The concept of getting your diet back into balance is fantastic. It is never too late so starting here and now will set you up well for the New Year. Remember that any food or drink is potentially toxic if we have too much. Even water can be toxic, so the goal of any detox diet is to restore balance into your diet in an ongoing way. We need to think about replacing what we are eating too much of with what we are not having enough of. For each person this is different and a good place to start is taking a look your drinks. Once you have written down what you drink and how much you can develop your own ‘detox diet’. For some it is clear that you are having too many sugary drinks which contribute to weight gain or tooth decay. For others it may be that alcohol is an unnecessary addition to your intake for similar reasons that these drinks are dense in calories and have they have other undesirable side effects too. Other people will see that they are consuming large amounts of caffeine. Add water and low fat milk to your list of drinks to provide hydration and nutrients. We could then look at our food intake and decide on changes we could make to ‘detox’ and to become a way of life. One hint which would benefit most of us would be to minimise salt consumption which is hidden in foods and causes health problems.”

Nikki Talacek is a Registered Dietitian who works with one of New Zealand’s leading weight loss surgeons Michael Booth and provides dietary advice to obese patients undergoing bariatric (weight loss) surgery. She comments:

“Detoxing is very common after Christmas, however a detox diet is often just a fast (starvation or very low calorie diet), combined with laxatives, in disguise as something “healthy” to cleanse the system after a period of indulgence. Often the detox programme says it will cleanse our bodies of toxins (implying toxins are stored within the body, without a way to be eliminated), though our bodies are well set up to deal with the toxins we take in, and a detox diet is not necessary for this. A detox diet can do more harm than good, as since they are often starving the body of much needed protein, carbohydrates and other nutrients the body can go into starvation mode, which in the long run could lead to nutrient deficiencies (if followed for an extended length of time) and it can also lead to increased weigh gain once the programme is completed. I never recommend a person follows a detox diet, and in my experience, everyone I have spoken to always gains more weight once the stop the programme, than they lost doing it.

“The best way to lose weight in the New Year is to adopt a healthy eating programme, with plenty of fresh vegetables, fruit, wholegrain carbohydrates and lean protein. The dinner plate should be at least half vegetables, a quarter lean protein and a quarter carbohydrates (preferably wholegrain). Exercise is also vital for health and weight loss, and my experience shows me that without exercise, weight loss is much harder not only to achieve, but also maintain. A common New Years resolution is to ‘eat healthy, exercise more and lose weight’.

“Start by making small changes which are easy to achieve and will become part of a new lifestyle, then as these small changes are slowly incorporated and become habit, make a few more small changes – trying to change too much at once (i.e. a dramatic change to what used to be done) is generally not sustainable in the long run and the diet and or exercise regime is abandoned and old habits re-emerge (and hence weight loss is not maintained). Pick 1-3 small changes (e.g. switching from full fat milk to low fat milk, reducing the amount of sugar in tea or coffee and walking 3 times per week for 30 minutes) each week, and then the next week pick another 1-3 small changes, or further develop the initial ones (e.g. increase the walking from 3 times per week for 30 minutes to 4 times per week for 40 minutes, stop sugar in tea and coffee, ensure at least half of dinner is vegetables) and so forth.

“Most importantly – don’t give up, weight loss is a slow process, when done via diet and exercise, and losing ½-1kg per week is considered safe and sustainable. Weight plateaus are common, and should pass with time as long as the exercise and healthy eating continue, though from my experience increasing exercise generally helps the weight to start coming off again. Don’t let them discourage commitment to the “new you”.

Kath Fouhy is a Registered Dietitian, and a Nutrition Consultant in Wellington, comments:

“Firstly it’s a ‘diet’ and diet is just the word DIE with a cross at the end – anyone who has been on a diet (which is most people) knows that you can easily loose weight but diets are all about deprivation and you can’t sustain them so you end up re-gaining the weight you lost (sometimes even more) so back to where you started!

“Secondly, detox diets are not supported in scientific literature. Our own bodies are constantly detoxifying by filtering out, breaking down and excreting toxins….how else do you think we handle things like medications, alcohol, bacteria, by-products of metabolism and digestion? Our major organs like our liver, kidneys, intestines, lungs and skin do it all for us.

“Detox diets often encourage the elimination of total food groups which claim many things including weight loss, reduced headaches, less bloating, clearer skin etc. Eliminating entire food groups is not recommended for many reasons as it may lead to the depletion of essential vitamins and minerals such as calcium, phosphorus, sodium and potassium which can lead to dehydration and altered electrolyte balance. As for the weight loss – well most of it is water, not fat loss which means it is easily regained once the detox in completed.

“To feel better after the festive season we just all need to ‘de-junk’ rather than ‘de-tox’. Ensuring you are getting your 5+ a day as well as consuming the right amount of whole-grain carbohydrates, protein and essential fats as well as including some exercise in your day will get you back on the path to feeling great.”

Chris Cook is a Community Liaison Dietitian at Auckland City Hospital, comments:

“Unfortunately the best way to lose weight after a period of excess remains the same – unfortunate because actually there is no magical approach to weight loss. Strip back all the high fat and high sugar extras and leave a selection of healthy foods including vegetables and fruit, wholegrain bread and cereals, lean meat fish, chicken or legumes, and low fat milk or milk products. If you cut out one of these groups or categories, your body will be short of useful nutrients.

“Think about your alcohol and sugary drink intake, these add lots of calories but do not contribute to your feeling full. Avoid the ‘cutting out carbs’ trap. If you do go the low carbohydrate way, you will lose weight because your body loses fluid but not necessarily fat. To lose fat, you have to eat fewer calories (or energy) than your body needs. This process will be assisted by being as active as possible.”

Further Information

To talk to these or any other scientists about issues raised here, please contact the Science Media Centre on tel: 04 499 5476 or email:

More Information on detox and fad diets

* The New Zealand Dietetic Association provides information on how to spot bad dietary advice and how to lose weight sensibly.

* UK-based Sense about Science has produced a leaflet Debunking detox where The Voice of Young Science challenges the detox myth and brings you the Anti-Detox promise. They have also produced a Detox dossier on their hunt for the evidence behind detox claims made for products and diets.

* The British Dietetic Association fact sheet on detox diets also outlines why detoxing is not advisable in the New Year.

* Guardian columnist Ben Goldacre also provides comments on detox diets on his Bad Science website.

New research on successful weight loss strategies

Is Mindful and Intuitive eating the way to success? A paper just published in the Journal of the American Dietetic Association, suggests that mindful eating, which is about listening to hunger, fullness and taste satiety cues, may help in the battle to lose weight.

Psychological aspects of weight loss and weight maintenance: New research just published in the Journal of the American Dietetic Association, suggests psychological processes such as increased dietary restriction, self-efficacy, confidence and the ability to tolerate discomfort (e.g. feelings of hunger) in the pursuit of healthy behaviour change goals are important components of effective weight loss.

Strategies of overweight adolescents who successfully lost weight: New research just published in the Journal of the American Dietetic Association, reports that adolescents who successfully lost weight were more likely to report drinking less soda, increasing their exercise level, consuming diets higher in protein and watching less TV.

Physical activity associated with fitness and weight status among adolescents: New research published recently in the Journal Arch Paediatr Adolesc Med reports that exercise is associated with better weight status among adolescents.

The above papers are available for registered journalists in the resource library of the Science Media Centre website.

Notes to Editors

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