The Detox Diet – Does It Work?

Avatar for Hadyn Luke Hadyn Luke posted this on Tuesday 18th of February 2014 Hadyn Luke 18/02/2014


The Detox Diet – Does It Work?

The start of the year is typically a busy time for personal trainers. As many people make resolutions to lose weight after the excesses of Christmas, fitness instructors often have clients who are following a diet. This blog focuses on one in particular, the detox diet.


The detox diet is all about restricting the type of food eaten for a period of time, in the belief that this will “cleanse” the body and remove the toxins we normally ingest.

The body is actually extremely efficient at doing this naturally on a daily basis through the organs and immune system, for example:

  • The liver filters out alcohol
  • The kidneys remove waste through urine
  • The lungs eliminate airborne toxins
  • Toxins can be removed through dead skin and sweat

Detoxing is a concept that has been around for many centuries and programmes range from fasting days to juice diets and diets lasting several weeks in which certain food stuffs are cut out then gradually reintroduced.


Generally, detox diets will recommend a high intake of fruit and vegetables. These include:

Asparagus – anti-inflammatory and known to help the liver metabolise toxic compounds

Broccoli – works with the enzymes in the liver to make toxins easier to eliminate

Green tea – high in antioxidants (see our blog on Personal Training and Nutrition – Does green tea burn fat?)

Forbidden substances include:

Sugary foods – sweets, chocolates and cake are all high in sugar, which can be damaging to liver function and can even contribute towards the development of diseases such as diabetes.

Alcohol – this is processed by the liver and excessive alcohol intake can lead to fatty liver, hepatitis and cirrhosis.

Caffeine – caffeine can be dehydrating, forcing the liver to work harder (see our blog What do you know about caffeine?).


There is a lot of anecdotal evidence around detox diets, without research available to support the claims made. A personal trainer may find that what works for one client doesn’t work for another, especially as some people may have food allergies or food intolerances.

The premise of a detox diet is that it will help to remove any excess toxins that the body has not been able to eliminate and that have, therefore, built up over time. However, there is as yet no scientific evidence that detoxing is necessary to remove excess toxins from the body – or indeed effective at doing so.

Another key claim is that a detox diet will help you lose weight. However, following a low-calorie diet of any kind can lead to weight loss and it’s important to avoid putting the body into starvation mode, which can slow down the metabolism. A personal trainer would usually suggest that a better approach is to eat a healthy diet all year round, rather than binging and detoxing.

Other claims include improved complexion and a reduction in bloating – however, the latter is recognised as a side effect of reducing calories and salt intake.

Eating more fruit and vegetables – a component of many detox diets – is known to be beneficial for health on its own merit.


Anyone following a detox diet may experience side effects, especially if they have dramatically cut their calorie intake or drastically altered their normal dietary intake.

These can include:

  • Low blood sugar levels and low energy levels
  • Fatigue
  • Dizziness and nausea
  • Muscular aches and pains

A personal trainer should be aware that clients following a detox diet may run the risk of underperforming or even fainting when carrying out a fitness programme – whether training in the gym or taking part in a fitness class or sporting activity.

People who should never go on a detox diet include children, pregnant women and those with diabetes.


Many personal trainers will have some experience and training in food and nutrition (see our blog Do you know your macronutrients? and our blog on PH levels) and can make suggestions such as working from the eatwell plate, a recognised tool, which can be found on the NHS Choices website (although, this plate has also led to some recent criticism, such as being influenced by wheat-based food manufacturers).

However, as every individual is different, a client who wishes to follow a specific diet is best advised to take advice from a trained dietician or other medical specialist. Clients may have particular health issues, which can then be taken into consideration.

Most fitness professionals will recommend that the best results are achieved by making small lifestyle changes over a long period of time rather than “quick fix” dieting, which is harder to sustain and can even be dangerous.

Subscribe to the blog

Interested in becoming a personal trainer
or sports massage therapist?

Leave your details below and a member of the
CMS team will contact you shortly.