If you are looking for long term success with your results, the truth is you need to look beyond the latest fad diet. The newest diet and quick fixes have been actively involved in the health and fitness industry since it became an industry. People have always been chasing that miracle cure, that option that makes everything a bit easier and results not as hard to get.

Some of the fad diet options over the years include:

  • Keto Diet
  • Intermittent Fasting
  • The 5-2 Diet
  • Paleo Diet
  • Gluten-free Diet
  • Vegan and Vegetarian Diet
  • Zone Diet
  • Whole 30 Diet


The list goes on and will always get bigger the more new information enters the market.

With so many various diets out there, being backed by a variety of claims in the media and online, it would only be normal for you to be intrigued about how one of them will ‘have you loosing 10lbs in a week’.

While it is true that all of these diets can work in the short term, not all are healthy. In fact, most are not sustainable in the long term. The more extreme the diet = the lower the chance of adhering to it. I have picked two of the most talked about diets at the moment to discuss and debunk the claims

Read on to get the truth about a few of the most popular current diets, and find out what the science really says.




Fad Diet – Keto


What is the keto diet?


Very low carbohydrate diets, or ketogenic diets are defined by their ability to cause ‘ketosis’. This essentially means to raise ketone levels in the blood stream. This occurs when carbohydrate intake is restricted to a maximum of 50g/day. The severe restriction of carbs leads to fats being broken down in a different way: into ketones which can then be used for energy. The idea of a keto diet, is to force the body to burn fat instead of carbs for fuel.


What are the claims of the keto diet?


Advocates of the keto diet claim people lose weight more effectively when their carbohydrate stores are limited. This is based on the ‘insulin theory’ that suggests carbohydrates causes a rise in insulin levels. This results in the body storing fat. It is believed that over time, body cells become resistant to insulin, and the pancreas produces more of it. This leads to the body being in fat storage mode.

Essentially, pushing the body into ketosis is believed to inhibit fat storage and promote fat breakdown. The majority of the evidence backed science shows that it is actually the high levels of body fat that makes people insulin resistant, and losing weight results in insulin levels being controlled.


Does the keto diet work?


Adhering to a keto diet, can result in weight loss. However, not for the reasons believed by advocates. The reason for the weight loss is initially due to the depletion of glycogen stores with hold water in the body. No carbs = less water = less weight.

The other reason keto diets work is because they create a caloric deficit. Cutting out an entire macronutrient is automatically going to greatly restrict the foods that you can eat. As we have learned, protein takes longer to digest, therefore, it is difficult to overconsume foods such as meat and eggs, and with limited choices, people will consume fewer calories.

Both protein and fats are more satiating. They will help you feel less hungry and eat less spontaneously throughout the day. If you eat less calories than you are expending = you will lose weight. Simple as that.

Randomised Controlled Trials show that ketogenic diets and low-fat diets produce similar weight loss results. The majority of meta-analysis (pool of big studies), show that weight loss differences between the two are minimal at 12 months. Although low carb diets produce a slightly greater weight loss at 6 months (Johnston et al., 2014).

In one of the largest studies to date The Diet Intervention Examining the Factors Interacting with Treatment success; researchers found after 12 months, there was no significant difference in weight loss between a low-fat vs low carbohydrate diet (Gardner et al., 2018).

Low carb and keto diets are not superior to other dietary approaches for weight loss. While they may have advantages in controlling your appetite, are you really willing to never have a beer, eat a slice of pizza or enjoy a bar of chocolate again?

Think SUSTAINABLE and LONG TERM, not just a quick fix where you may be twice as bad off after you have finished the diet!



Fad Diet – Intermittent Fasting


What is the intermittent fasting diet?


Intermittent fasting, is when you only allow yourself to eat within a certain timeframe. It can involve fasting for between 12 and 16 hours, and eating for 8-12 hours per day. In your ‘eating window’ there are no rules to what or how much you can eat.


What are the claims of the intermittent fasting diet?


The idea of this form of time restricted eating, is to match you’re eating time to your bodies internal body clock or circadian rhythm. Some studies have previously shown that circadian rhythm disruption can negatively impact appetite, energy expenditure and blood glucose. As a result, the idea is that time restricted feeding will promote your body to work more efficiently, resulting in weight loss and health improvement.


Does the intermittent fasting diet work?


Sounds promising?

Not when you find out most of the studies mentioned have been carried out on mice and fruit flies (Hatori et al., 2012: Chaix et al., 2014). The evidence of intermittent fasting for humans is limited and although a number of studies have shown positive results. A review of 11 studies which compared intermittent fasting and calorie restricted diets showed no significant difference in weight loss between groups (Rynders et al., 2019).

Intermittent fasting is simply just another variation of creating a calorie deficit by reducing the window in which you are allowed to eat. This will cause a calorie restriction. As we know eating less calories = weight loss. Yes, it may be a useful tool and work well for some people, but will you be able to sustain it forever? Or will you fall out of it when you have your next social event and get back into old habits?



Other fad diet choices


Other people may swear of vegetarian, vegan or even gluten free diets for weight loss. How are they similar to the diets mentioned above!?

You guessed it.. just another way of restricting caloric intake, by not being allowed certain foods!

No foods should be ‘not allowed’ or categorised as bad. We won’t even mention the so called ‘SYN’ foods they teach about in Slimming World, because again, no food should be demonised. We may require certain foods more than others, however the minute you cut a certain food group out completely, you’re just going to want it more.

When you introduce it back into your diet, you may be more likely to overeat it and put the weight right back on. This is why every food should be allowed in a diet. You should aim to make it sustainable! Sure, some populations will benefit from certain diets. Examples include those with epilepsy from keto, gluten intolerant people with the gluten-free diet, and of course if you are vegan or vegetarian for non-weight-loss reasons.

For the general population however, introducing a slight caloric deficit while still eating the foods you enjoy in moderation, along with adding more movement to your day, will do just a good of a job as these diets and be more enjoyable!



In Summary


In conclusion, the health and fitness industry has always been filled with a fad diet or quick fix promising miraculous results with minimal effort. However, it is important to approach these claims with caution. It is important consider the long-term sustainability and health implications. While diets like the keto diet may initially lead to weight loss, the reasons behind it are often misunderstood. The depletion of glycogen stores and the creation of a caloric deficit are the main factors contributing to weight loss.

Similarly, intermittent fasting may offer some benefits, but the evidence for its effectiveness in humans is limited. Restrictive diets that eliminate entire food groups can be challenging to maintain. This in turn, may lead to cravings and overeating.

Instead, a balanced approach that includes a slight caloric deficit, moderation, and increased physical activity can lead to sustainable and enjoyable results.



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