What are the dangers of a detox diet?

The theme of 'detoxing' in the new year fills the media every January. Detox diets are presented as a healthy way to rid our bodies of harmful toxins, but this is not supported by science. In fact, detox diets can be dangerous to our physical and mental health.

The dangers of the "New Year, New Me" mentally

January has long been associated with self-reflection and goal setting. While our New Year resolutions are well intentioned, too often they result in pressure, abandonment, self-criticism, and low self-esteem.

The desire to make a change at the beginning of a new year isn't an intrinsically bad thing, but the pressure to make a drastic change runs the risk of damaging both our physical and our mental health.

"Change in our life must be sustainable," says Ruth Micallef, accredited sub-specialised eating disorder counsellor. "More often than not we are encouraged into 'big bang' changes at New Year."

With each new year, the idea of 'detoxification' saturates the media and encourages a great number of us to try a 'detox diet'. This type of dieting aims to rid us of alleged toxins in our bodies that are held responsible for a number of complaints, including bloating, tiredness, headaches, and low moods.

A detox diet typically involves a drastic reduction in calorie intake and increase in water consumption with the intention of 'cleansing' our bodies and 'washing out' harmful toxins. New Year detox diet narratives are based on making an instant and dramatic lifestyle change, but this mindset is flawed.

"Inevitably, these instant changes lead to quick failure and feelings of shame, which certainly doesn't help us create and grow healthier habits," adds Micallef.

The detox myth: why should you not detox your body?

Many different detox diet programmes are advertised around New Year, but they are typically very low-calorie, and often include one or more of the following approaches:

  • Eating a narrow range of specified foods.
  • Fasting (not eating for an extended period).
  • Drinking only juices or similar beverages ('drink cleanses').
  • Taking commercial dietary supplements.

Our natural detox system

These are significant dietary changes that have a physiological impact, meaning they can interfere with our normal bodily functions. Yet our bodies already have an effective system in place for removing toxins. Micallef explains:

"The liver and the kidneys are incredible natural detoxicants; they break down any harmful substances that we put into our bodies, or by-products that the body creates."

The liver acts as the body's main filter, producing proteins (known as metallothioneins) that neutralise harmful toxins, and enzymes that support the metabolism and the body's defence against toxins. The kidneys filter out unneeded waste products and toxins through urine.

There are also other parts of the body protecting us from harmful substances:

  • Immune system - identifies potentially harmful foreign substances (pathogens) and eliminates them.
  • Intestines - lymph nodes in the small intestine identify harmful substances and prevent them from being absorbed along with nutrients into the blood.
  • Skin - provides a barrier against harmful substances, stopping them from entering.
  • Respiratory system - hairs in the nostrils prevent inhalation of large foreign particles. Smaller particles that reach the lungs are removed from the airways via mucus.

Our bodies are highly equipped to remove harmful substances, without us implementing drastic dietary measures.

Do New Year's diets actually work?

We're all familiar with the phrase, 'new year, new me'. January is a time when many people set r...

Detox diet: questionable benefits

Despite the commercial attention given to detox diets, there is little clinical evidence to show these are healthy and beneficial at eliminating toxins. There have only been a small number of studies, and while some suggest positive results, experts warn that many are of low quality with few participants, a high risk of bias (selection of study participants, study design or interpretation of data that deliberately encourages the desired result) and study design limitations.

If your goal is also to use a detox diet for weight loss, you will almost inevitably be disappointed: a detox diet is highly unlikely to provide long-term, healthy results. While some research indicates that a detox diet can lead to initial weight loss, it's important to note that this type of low-calorie dieting is often unsustainable.

We are unable to follow detox diets for long periods, as our bodies require more nutrition and more calories to function healthily. Yet, rather than returning to our original weight, there's a risk of gaining weight more once we resume our normal eating habits.

"Yo-yo dieting and unhealthy snap calorie deficit diets wreak havoc on our metabolism," Micallef explains. "Often this results in us gaining even more weight than we started with."

This is because detoxing - and other very low-calorie diets - lower the body's basal metabolic rate - the amount of calories it needs to perform the most basic life-sustaining functions.

Detox diet: potential risks

Not only is weight gain a possible long-term outcome, any initial weight loss may in fact be fluid loss. Detox diets are typically low in carbohydrates and often involve herbal teas which can act as laxatives, both of which can result in more water being expelled from our bodies. Consuming too much food and drink that have a laxative effect can result in dehydration.

A detox diet usually involves drinking a great deal of water, which is intended to 'wash' toxins out of the body. While being well hydrated is healthy, drinking too much can cause water intoxication, a condition that can cause serious health problems, and in the most severe cases can be fatal.

Many detox diets severely restrict the types of food you eat. In doing so, there's a high risk of not getting all the nutrients you need for your body to function healthily. Often, a detox diet will deprive you of adequate levels of protein, fatty acids, vitamins, minerals and other essential substances.

It's also worth noting that alongside detox diets, there are also many potentially dangerous 'detoxification' products on the market. Some may contain harmful ingredients: examples include 'detox juices' which may contain bacteria that can cause illness, or laxative supplements which can cause diarrhoea severe enough to lead to dehydration and electrolyte imbalances.

How a detox diet affects your mental health

It's not just our physical health which can suffer, but our mental health as well. A detox diet is a type of restrictive diet that sends the dangerous and false message that we should dramatically reduce our calorie consumption and narrow the variety of foods we eat.

"Telling us that specific products or restrictive diets will help 'detox' the body can send us into a spiral of restriction, or bingeing and purging," says Micallef. "Detox diets generally result in us swinging from restrictive, unrealistic diets, to bingeing after the calorie deficit.

"Additionally, we can spiral into disordered eating habits, constantly searching for the 'magic bullet' to help us cope with our traumas and life stressors via our body image. Inevitably, 'detoxing' pushes us away from healthy sustainable life choices that would, in fact, benefit our bodies."

Sadly, research into detox diets such as juice cleanses show the dangers they pose to mental health, namely through links with eating disorders. The idea that it's good to greatly restrict what you consume can lead to an unhealthy relationship with food.

A healthy approach to "New Year, New Me"

If you want to make some positive lifestyle changes in the new year, self-love is an important lesson. Remember to make sure your goals are both healthy and realistic. However, should your resolutions not last, don't beat yourself up. Micallef believes that the best and easiest way to 'detox ourselves' is "simply to treat our bodies with compassion and care".

The best way to ensure your body is protected against toxins is to support your body's natural self-cleaning functions. You can do this by following a healthy, well-balanced diet that contains a wide variety of nutrients. Drinking enough water, getting good sleep, and exercising regularly will also help. These long-term, sustainable interventions are recommended by experts.

The good news is, they are also free of dietary restrictions that can lead to hunger. Usually, the healthiest changes you can make in your life are easier to implement.

"When making any sort of significant change in our life, we need to make gradual, gentle movements towards it, to allow ourselves a sense of stability and sustainability with the action we have made."

Read next

Take our quick 5-minute survey to share your thoughts on Patient.info articles

Start survey
newnav-downnewnav-up