Five Reasons Fad Dieting Fails You

Five Reasons Fad Dieting Fails You

Barry Kerrigan |

‘No greens.’

‘No grains.’

‘Only lemon water upon waking.’

'I only eat strawberries and drink Processco.'


Sound vaguely familiar?

Well, it should because these statements are all commonly presented to us in the form of fad diet marketing.

What could possibly go wrong with approaches like these? Well, it turns out that there could be just a few things.

The return of the likes of the Ketogenic diet has served to the remind us that the fad diet cycle has a strong pull on our sensibilities.

I’ve outlined five reasons why fad diets ultimately let us down.


1/Lack of credible endorsements

A prime example of this would be the ‘Carnivore diet’. While being promoted by the likes of Jordan Peterson may appear to give the Carnivore diet credibility, there’s no research to suggest that the exclusive meat-only diet is research backed.

While many proponents wills point out that animal products contain plenty of vitamins, protein, fats essential to the body (none of which I am disputing), there’s too much data to suggesting that eating plants and other sources aside from meat is an overall better approach to nutrition.

At Kerrigan's we love meat. There's nothing better as a source of natural protein. But you need your greens too!


2/Fad diets always focus on EXCLUSION rather than INCLUSION

Image result for vegetable only diet

Specific-named diets always have restriction in place. It’s how they operate and suck us in. They promise us that by removing ‘this one food’, we will reap the rewards of a ‘fitter’, ‘flatter’, ‘more toned body’ in less than 30 days.

Let’s take a look at it from a higher perspective, however.

We know that most fad diets rely heavily on restriction or exclusion of some food group, food item or misunderstood aspect of nutrition.

There is evidence that restricting foods creates weight loss. However, it’s rarely due to the ‘processes’ outlined by a particular fad. It’s always down to calorie restriction, removal of lower quality food sources and the knock-on effect of ‘health-seeking’ behaviours.

Weight loss occurs due to your reduced options and new lifestyle factors that you adopt.


3/Their claims transcend sense

The pull of a fad diet often comes down to the magnitude of the benefits that are ‘guaranteed’. The big problem here is that a lot of these claims are pretty much made up. Or even worse, they are borrowed from research into an actual named diet.

The most common claims that we see thrown about include the likes of ‘improved mental clarity’, ‘faster weight loss’ (not due to calorie restriction but to insulin sensitivity, I might add), ‘decreased inflammation’, and ‘improved testosterone levels’.

These are all shiny objects to clamour for but lack solid evidence.

 'Extraordinary dietary claims require extraordinary evidence..'


4/Deficiency potential

Seems like a bit of a no brainer but anytime where restriction is the driving factor in seeing results, deficiency potential is high. Advising not to eat plants or grains fat and relying exclusively one or two particular foods will likely expose you to nutrient deficiencies.

While most people may not experience this in the length of time that they experiment with the a fad diet (Hello adherence factor), a more long term usage may place you at a higher risk of deficiency.

Plant-based food sources are good for us. Grains are good to, in most cases. Dairy is unbelievably nutrient rich. Other animal products are also good. Eliminating one entirely based on spurious claims is NOT good for us.


5/Adherence Potential

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By now I hope you’ve heard the phrase ‘the best diet is the one that you can stick to’. This rings particularly true here. While many might feel that they could stick well with an all INSERT FOODS GROUP HERE diet, the reality is that our food environment is so ripe with variety (both good and bad) that sticking to one thing only is very difficult.

Commitment rules when it comes to achieving a goal. With any fad diet, the overly restrictive profile means that long-term adherence and therefore goal success is tough to see…

The goal of this short critique is to show that dietary approaches proclaimed by famous folk often fall short of the eye test. They rarely pass the evidence test either, the one that usually relates to effectiveness and health.

When it comes to choosing a diet to follow, look for the ones that emphasis overall dietary quality, promote inclusiveness of foods groups and focus on solid, sound scientific benefits on your health.


Rabin Das is an MNU Certified Nutritionist and holds an MSc in nutrition and metabolism. Check him out on Instagram or at 

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