• Cara-Lee Compton


A five-part series on nutrition and health,

by Jenna Selley

In a society filled with people relentlessly seeking the next quick-fix to satisfy their desire for instant gratification; it is no surprise that fad diets rule a large portion of the dieting culture. With so many products and people telling us a million different things, it is easy to be utterly convinced or easily swayed into embarking upon a dieting trend without first consulting a professional. It goes without saying that you will always find an article in support of a diet, as well as one against that very same diet. If it’s too good to be true, it probably is. Nutrition is also a field of study which regularly has new discoveries and evidence; and it is important to keep up with these developments as the once well-known concepts and recommendations are always subject to change.

What is a fad diet by definition?

A fad diet is a standard dietary recommendation which promises unreasonably inflated or quick weight loss and/or health benefits. This widely shared enthusiasm is often short-lived and takes little to no consideration for an individual’s needs. It is mostly a “one size fits all” approach.

Let's touch briefly on a few of the more popular dieting concepts in the modern world:

The Ketogenic Diet:

The Ketogenic diet is typically characterized by low carbohydrate (5 – 10% of total calories), moderate protein (10 – 20%) and high fat (70 – 80%) and has many similarities to the Atkins diet. It helps to lower blood sugar and insulin levels; and shifts the body’s metabolism from using carbohydrates as its main source of energy- to breaking down fatty acids into ketone bodies to be used for energy by the cells of our body (ketogenesis). This mechanism is stimulated by low insulin levels and high glucagon levels.

The diet was originally used in the 1920’s to treat epilepsy, and has had promising results. The popularity of the ketogenic diet spiked around 2017. One 2018 open-label, non-randomized, controlled study showed that achieving ketosis can help to decrease HbA1c, increase insulin sensitivity, reduce medication use and promote weight loss within 70 day. Research is still required in order to assess the sustainability of this diet, however the keto diet is regarded as being very restrictive and hard to maintain. There is some evidence that suggests that the Keto diet does help to control appetite. Initial weight loss is often in fact rapid water weight loss, not fat mass.

This diet advises the restriction of carbohydrate intake to less than 50 grams per day. The Ketogenic diet is also almost void in fibre (commonly found in high carbohydrate foods). Both soluble and insoluble fibre is essential for the maintenance of gut health. The absence of fibre in the diet can result in the disruption of bowel movements, e.g.: constipation or diarrhoea. Vitamins and minerals (micronutrients) are most commonly found in fruit, vegetables and grains. Micronutrient deficiencies can become a health risk should these food groups be excluded/ drastically reduced in the diet.

The Keto diet is the most similar to the Atkins diet, which was first popularised in or about the 1960’s.

The Atkins Diet:

This diet was founded by cardiologist Robert C, Atkins in the 1960’s6. It is characterised by a low carbohydrate diet (and not necessarily a high protein diet, but can often become such). The Atkins diet doesn’t require calorie counting or portion control, only the tracking of carbohydrate intake.

There are 4 phases of the Atkins diet:

1) Induction: (2 weeks)

· Eat 20g of carbohydrates a day (mainly from non-starchy vegetables)

2) Balancing: (This phase is recommended until you are 6kgs from your goal weight)

· Total carbohydrate intake should begin at 25 grams, then increase by 5g of carbohydrates per week

3) Pre-maintenance phase:

· Begin this phase by adding an additional 5 grams to your total net carbohydrates from Phase 2. If you still lose weight- add an additional 10 grams of carbohydrates per week whilst you are still losing weight.

4) Lifetime Maintenance:

· Maintain your total personal carbohydrate amount where you are no longer gaining or losing weight. Continue this way of eating throughout your life.

Long term studies prove that the Atkins diet is not more effective than any other standard weight-loss diet and that majority of people regain the weight they lost (regardless of diet plan). Several studies suggest that the reason for weight loss when using the diet is indirectly attributed to subsequent calorie restriction and appetite reduction since a high protein and fat diet can slow down digestion and keeping one fuller for longer thus reducing overall calorie intake. A doctor should be consulted should you use diuretics, insulin medication or oral diabetic medication. The Atkins diet and is not recommended for pregnant and/or breastfeeding women, or people with severe kidney disease (i.e.: a low protein diet is recommended for individuals with kidney problems).

The Banting Diet:

The Banting diet was first prescribed by William Banting in the 1860s, but gained most of its popularity in 2013 by its reintroduction from South Africa’s very own Tim Noakes and his book “Real Meal Revolution”. It is typically a low carbohydrate, high fat diet (LCHF). This diet promises specifically to reverse Type 2 Diabetes and high blood pressure and results in rapid weight loss. The Banting diet encourages eating wholesome foods over processed foods. The original Banting diet comprises of 4 daily meals (30 grams of carbohydrates per meal) and fruit as a snack (60 – 90 grams of carbohydrates). Food types such as bread, beans, butter, milk, sugar, beer and potatoes must be avoided. Tim Noakes adapted this diet. The macronutrient composition somewhat resembles the Keto diet: carbohydrates (5 - 10%), fat (65 - 90%) and protein (10 - 35% of daily calories).

Tim Noakes advocates the 4 phases of the Banting Diet:

1) Observation: (1 week)

· Track exactly what you are eating, make no adaptions

2) Restoration: (2 – 12 weeks)

· There is a list of foods which should either be eliminated, limited or included

3) Transformation:

· The food limitation list gets more refined and a strict low carbohydrate intake is introduced

4) Preservation:

· Once you’ve achieved your desired weight goal, you can slowly reintroduce foods that were previously not allowed. There is still a list of foods that will never be allowed (including sweets, gluten, grain based products, dairy related foods, certain oils and processed meats).

There is very little literature on the effects of how the Banting diet (specifically) affects weight loss but plenty of scientific research on low carbohydrate, high fat diet approaches to weight loss. The Banting diet is also very restrictive and not very sustainable. Banting promotes the same mechanism as mentioned above: by restricting carbohydrates, the body works to break down fat to meet energy demands. There are scientific articles supporting the claims of: increased insulin sensitivity, lower blood sugar levels, decreases in high blood pressure levels, improved triglycerides and Hb1Ac. However, long-term evidence is lacking in the benefits of LCHF diets and the safety of this diet over a more extensive period of time. Scientific evidence also suggests that a high fat diet can increase your risk of hypertension and thus stroke and heart attack, by increasing ‘bad cholesterol’ (LDL) and blood vessel elasticity. Hence, the potential long term health risks may outweigh the short term benefits.

The Paleo Diet:

The Paleo diet, also known as the Paleolithic, caveman or Stone Age diet is essentially a modern age diet which mirrors the food choices of primitive man. It was originally a predominantly plant-based diet that consisted of fruit, vegetables, nuts, roots, etc; but recent adoptions focus additionally on meat products. This diet cuts out refined carbohydrates, sugar, legumes, oil, alcohol, dairy products, preservatives and processed foods.

The Paleo diet gained notoriety in the 1970’s. Several studies have highlighted evidence of improved body composition and metabolism when compared to a more 'Westernised' diet. There are however a few variations in the modern day version: some including more starchy foods, others focused on lower carbohydrate intake and others are more meat oriented. There are some controversial views, leaving grey areas as to exactly what primitive man ate, for it is after all- all hypothetical.

In the years 2013 and 2014, the Paleo diet was reported to be the most searched method for weight loss on the internet. Research has shown this diet to be less energy dense, richer in fibre and micronutrients. Some studies say that the Paleo diet may possibly put one at risk of Calcium and Vitamin D deficiencies due to a lack of dairy intake; as well as possibly increasing the risk of developing heart disease and other cancers should they exceed their daily protein and saturated fat requirements.

Medication supervision is recommended for those choosing to follow the Paleo diet, especially those who have underlying heart, liver, kidney or pancreatic disease or conditions.

I would caution against any diet which excludes one or more entire food groups. Should you be following the Paleo diet, I would recommend adapting the diet to make allowance for dairy, legumes and beans and whole grains for a more balanced diet.

The Blood Type Diet:

The Blood Type diet was created by natural pathologist Peter J. D’Adamo. This diet claims that there are different foods you should eat depending on your blood type and advocates strict restrictions and allowances on the different types of food. This diet also asks that processed foods and simple carbohydrates should be avoided (this could be reason enough for possible weight loss). Recommendations are also given for the different types of exercise to suit your blood type. The founder also sells his own line of supplements on his website “Eat right for your type”.

He summarizes the different blood type diets as follows:

Blood Type O:

· High protein diet: Meat, fish, fruit, vegetables, limit grains beans and legumes;

· Avoid: Wheat, kidney beans, lentils, corn, dairy.

Blood Type A:

· Mainly vegetarian: Vegetables, seafood, tofu, grains, legumes, fruit, turkey

· Avoid: Meat, kidney/ lima beans, dairy and corn.

Blood Type B:

· Balanced omnivore: Meat, dairy, vegetables, fruit, fish, beans, legumes;

· Avoid: Chicken, eggs, liver and “greens”.

Blood Type AB:

· Mixed diet: Lamb, fish, dairy, beans, legumes, tofu, grains, vegetables and fruit;

· Avoid: Chicken, kidney beans, corn and buckwheat.

One study showed that the Type A diet, a predominantly vegetarian diet, had improved health markers, in people not only with blood type A, but other blood types. In 2013, a major review concluded that the blood type diet is not scientifically supported. There is no research supporting the claims that this diet helps aid digestion, or gives you more energy. The Blood type diet also fails to address any other conditions such as hypertension, heart disease or cholesterol.


There are many different types of fasting. Some are solely liquid based, some are restricted to certain foods, some incorporate strict calorie restrictions, some limit the hours in the day in which you are allowed to eat and others skip a day or two of eating per week. During long periods of fasting the body is challenged when trying to maintain physiological balance. Behavioural, physiological and biological responses change in order to reduce metabolism and maintain tissue function and structure. Metabolism is thus shifted to depend on fat utilization when glycogen stores are depleted. Metabolism, hormones responsible for triggering digestion and the immune system is suppressed. Leptin is a hormone which is decreased in times of starvation, and will be explained in greater detail in the topic below.

Fasting is said to not be recommended for pregnant or lactating women, people with diabetes, children under eighteen years, the elderly, anyone with underlying medical conditions or on prescription drugs. Intermittent fasting is ultimately a calorie controlled diet which is a significant contributor to possible weight loss results. If you are fasting to detox your body, it is important to note that your liver and your kidney are your body’s main means of detoxing itself. Any imbalances and additional detoxing agents can even be counteracted in order to restore balance to the body. There is evidence that intermittent fasting may help prevent chronic diseases, but more research is needed. Research also states that “it is not a realistic long term solution”.

Strict calorie restriction diets:

Let's first look at some basic calorie counting concepts:

· No weight loss: Calories consumed = Calories used for energy throughout the day

· Weight loss: Calories consumed < Calories used for energy throughout the day

· Weight gain: Calories consumed > Calories used for energy throughout the day

Here's the tricky part. Too great a calorie restriction can actually be less beneficial. The more rapid and radical your weight loss journey, the greater your chances are of regaining that same weight. People need to be patient and wrap their heads around the concept of slower, more consistent weight loss approaches.

Radical calorie restriction (in attempt to lose weight) has shown to slow down metabolism significantly. Metabolism is our body's process of converting what we eat and drink into energy to be used in daily activities. Meaning that people with extremely slow metabolism will need to eat significantly less calories in order to maintain a weight compared to people with a faster metabolism. Fast weight loss can lead to an initial drop in body fat, which causes a subsequent lowering of leptin levels- the hormone responsible for controlling hunger, which researchers believe causes the higher cravings. I advocate the implementation of small habitual changes which can be worked into your daily life in a sustainable way.

So after the overload of information, you may be thinking, “Well what now then!?”.

Well, there is a silver lining in the end, because all of these diets and research studies can teach us a lot. Analysts compared different fad diets and identified the overlays in order to assess the common recommendations that all these diets share. The thinking being that if we incorporate these undeniable truths, we will achieve the desired outcomes. Below are a few simple tips, taking the positives from the above literature and avoiding the potential unwanted negative results of the cons.

● Cut down on sugar;

● Cut down on refined carbohydrates;

● Add more fresh vegetables to your plate;

● Eat whole foods (less preserved foods); and

● Avoid extremism.

Warning signs to look out for:

● Promises of rapid and radical results;

● Advertising propaganda;

● Unqualified people (many public figures) giving nutrition advise and self-proclaimed experts from their own experience;

● Profitable companies selling ideologies and benefiting from sales of their own products;

● "Good food" and "bad food" stigmas;

● Nutrition recommendations not based on peer reviewed articles;

Complete elimination of one or more of the main food groups (See Part One of the nutrition rated blog posts to find out more about how to balance the different food groups on your plate).

There is no one diet aimed at weight loss which will work for everyone. It is for this reason why a dietitian should be consulted for the assessment of an individual's needs. A high protein diet may be essential for one person (e.g.: malnutrition, surgery, burns...) and detrimental to the next (kidney failure). I would recommend you stop dieting. And start looking at how you can make sustainable, meaningful changes to your lifestyle. By working on a healthy relationship with food and your body image and making those small changes in your lifestyle, weight loss will come easily and naturally.

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