Fad Diets Explained: The Good, The Bad and The Ugly

In recent years, it is all too common to be bombarded with countless ads, emails and content from Instagram influencers, all hoping to cash in on the newest fad. These range from detoxes using things such as gel sachets, skinny teas and other such magic potions to celery juice diets and other bizarre ways of eating. Some even take this further, by suggesting seasonal fads, e.g. in the lead up to summer.

Nutrition is a bit of a minefield to navigate at the best of times and it can be hard to know what to believe. Misleading information and false advertising are often marketed so cunningly that we can’t resist giving the products or method a go to get the result desired. 

From raw food to clean food and keto – there are loads of fad diets out there tempting people with promises of instant weight loss. At FFF, we want to help you debunk the fads with useful guidance.

What is a fad diet?

A fad diet is a diet that rises quickly in popularity. Some go in and out of fashion over the years too. They are usually outside of the usual dietary recommendations and make unreasonable claims for quick weight loss.

What are some common fad diets and would we recommend them?

  1. Detox diet:

A ‘detox diet’ typically states the need to rid the body of toxins, and ‘cleanse’ our bodies. There are several ways people might choose to follow this diet, for example, juice cleanses or detox tea programmes. 

We would not recommend a detox diet. There is no evidence to support the claims that any diet can effectively ‘detox’ our body. Our body has natural (and very clever!) mechanisms in place for detoxing itself, whereby our major organs such as the liver, kidneys, gut, skin and lungs all play an essential role.

In addition to this, Fresh Fitness Food advocates gradual progress towards a clients’ goals, by creating sustainable lifestyle and behavioural changes. Detox diets can often be referred to as a ‘quick fix’, which we do not advocate.

  1. Alkaline diet:

The ‘alkaline diet’ claims that acidity in the body leads to disease. Therefore the ‘alkaline diet’ claims to remove ‘acid-forming foods’ and replace them with ‘alkaline-forming foods’ in the body.

We would not recommend the alkaline diet. There is no sufficient evidence to support claims that the alkaline diet provides any health benefits or prevents disease. 

The suggested mechanism of alkaline-forming foods is inherently flawed, since the body has its own mechanisms which regulate blood pH, and it is not possible to control this with diet. 

In addition, this particular diet recommends against high protein foods such as meat, lentils and fish, and so by following this diet, it’s possible for you to be missing out on essential nutrients.

  1. Ketogenic diet:

A ketogenic (keto) diet is a diet with a very high-fat content, moderate protein and very low carbohydrate content. There are variations on how the diet might be implemented, but on a typical ketogenic diet, about 75% of calories come from fat and only about 10-20% from protein and 5-10% from carbohydrates.

Our bodies mainly use carbohydrates and fat for energy. When the diet is low in carbohydrates (or when you are starving/fasting or doing intense exercise) our bodies will produce ketones from fat. Some tissues like our nervous tissue and red blood cells can normally only use carbohydrates as energy. Ketones, unlike fatty acids, can cross the blood-brain barrier and therefore provide the brain with energy. If the concentration of ketones reaches a certain point, we say the body is in a state of ketosis.

We would also not recommend the keto diet. There are very few instances where the ketogenic diet has been suggested to be beneficial, aside from in children with epilepsy.

Any diet that cuts out a whole food group or macronutrient is not something we would recommend. It is extremely restrictive and unsustainable. Further, it is not something we would suggest following without the supervision of a medical professional as there are a number of risks associated with it, including low blood sugar levels, vitamin and mineral deficiencies and issues related to gut health.

  1. Intermittent fasting:

Intermittent fasting (IF) is an umbrella term given to a variety of meal timing schedules, to cover various fasting periods.

The fasting periods can be anything from a matter of hours, for example from 8 PM to 12 PM the following day, alternate-day fasting, or calorie restriction on some days, and not on others. For example, the 5:2 diet. This is where an individual eats 5-600 kcal/day, two days a week and eats ‘normally’ for the other five days.

The other commonly-adopted form of intermittent fasting is the 16:8 diet, where it is encouraged to fast for 16 hours, and to only eat in the allotted 8-hour feeding window i.e. the aforementioned example of fasting from 8 PM – 12 PM.

There is no conclusive evidence to show the proclaimed health benefits of IF at this stage, although the research is ongoing. Currently, it seems to pose as a fad diet that enables those adhering to it to stay in a calorie deficit by skipping meals.

It is not something we would recommend here at FFF as a necessity for fat loss. 

What are the problems with fad diets?

Fad diets often have little, if any, scientific backing. They can often involve radical dietary changes, very low calories and, or the removal of entire food groups. This can have many detrimental effects on overall health.

Further, online influencers are often being paid to sell products and may not be using them themselves. Moreover, they are usually not qualified to be giving dietary advice. Their content can go out to millions of people – some on the younger side who perhaps look to them as role models and can be more impressionable.

What to look out for?

There are a couple of telltale signs of a fad diet. Therefore, there are a few things to look out for and avoid, including:

  • If the outcomes of a diet sound too good to be true – it likely is exactly that. 
  • Anything that sounds like a quick fix or guarantees a certain amount of fat loss in a short period of time.
  • Lists of ‘good’ and ‘bad’ foods – this can be a good indication of a fad diet.
  • A plan which excludes or severely restricts food groups or nutrients.
  • Anything with strict, rigid rules to follow.

What do we recommend when it comes to fat loss?

At Fresh Fitness Food we take a scientific-backed approach to nutrition, but we also fully appreciate the bespoke nature of this process and work to tailor your plan to you. Whilst a 20% deficit is applied on our fat loss plan, this is usually viewed as a good starting point for sustainable, controlled fat loss. However, we can adjust your plans throughout, depending on how our clients are progressing and, or feeling during their time with us.

Following a dietary approach that is personalised to your individual needs, overall goal and also one which enables you to get enjoyment and happiness from the food you eat is the way to go in our view!


If your goal is to drop body fat, we can help you sustainably work towards your goal, without compromising on flavour and enjoyment. 

Book a call with one of our all-knowing nutritionists to discuss your goal further. Have all the information you need but just don’t want to cook? Give our Fat Loss Plan a go with £50 off your 5-day trial with code BLOG50 – Start your trial here.

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Published by Georgia Chilton

In her teenage years, a love of food and rowing led Georgia into this field as she wanted to know how to optimise performance through nutrition. With a BSc in Nutrition and an MSc in Sports and Exercise Nutrition, she has the skill set to help you track towards your goals and maximise your potential.

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