A low carb, high fat diet plan known as Simple as Fat has recently come under fire from an advertising watchdog for claiming it can result in weight loss, reverse type 2 diabetes and fix erectile dysfunction.

In this article, we’ll take a look at what has happened and discuss, with consideration of the evidence, whether or not these claims are justifiable.

The ASA and its ruling

The Advertising Standards Authority (ASA) is the self-regulatory organisation of the advertising industry and is privately owned. As it is a non-statutory organisatio, it cannot interpret or enforce legislation. The ASA is financially maintained by a levy on the advertising industry and does not receive government funding.

Regardless, the ASA has ordered Simple as Fat to cease claims that its plan can help people lose weight and ‘cure’ health conditions such as type 2 diabetes and erectile dysfunction.

The ads, often in the form of tweets, said things like:

“You can cure type 2 diabetes with real food NOT more pills”.

The ASA said that claims of weight loss must be backed up by rigorous trails, not just anecdotes. It added:

“Because we had not seen evidence that Simple as Fat’s diet plan could result in weight loss we concluded the ads breached the code in that regard. We concluded the ads also discouraged essential treatment for conditions for which medical supervision should be sought.”

As part of their critique, the ASA cited the NHS advice on losing weight healthily, which warns of negative health effects of low carb, high fat diets:

“Many low carbohydrate diets allow you to eat foods high in saturated fat, such as butter, cheese and meat. Too much saturated fat can raise your cholesterol and increase your risk of heart disease and stroke.” [1].

Simple as Fat has received support from Dr Aseem Malhotra, an NHS cardiologist, who said:

“A low carbohydrate dietary pattern such as one promoted by Jon Gaunt [of Simple as Fat] is not only safe and effective at reducing weight and managing diabetes, but is far superior to traditional low-fat approaches.”

The evidence behind the Simple as Fat approach

Simple as Fat advocates a low carb, high fat lifestyle. Its diet plan appears to be based around predominantly real, unprocessed foods. For example, thumbnail images of avocado, salmon, eggs, berries and green veg populate the recipes area of their website. So what evidence is available to back the health claims made by Simple as Fat about their way of eating?

First, let’s look at weight loss. The ASA says that any claims of weight loss must be supported by rigorous trials. According to a charity called the Public Health Collaboratio, a total of 62 randomised controlled trials have been conducted to compare low carb to low fat approaches for weight loss. Of these, half (31) show a significantly greater weight loss in the low carb group, and none significantly favour the low fat group [2]. In addition, the results from our own Low Carb Program show that users have lost an average of 7.4kg (1 st 2 lbs) after one year [3].

Second, let us consider the claim of ‘curing’ type 2 diabetes. It is known that remission of type 2 diabetes can be achieved through diet, as shown by the Newcastle diet and our own Low Carb Program results, where 25% of users with type 2 diabetes were in remission at one year [3].

It is commonly considered better practice to use the term ‘remission’, rather than ‘cure’ or ‘reversal’ when discussing improvements in type 2 diabetes, as it is not yet known if people can return to their old ways of eating without relapsing.

In addition, the Public Health Collaboration reports that, of 15 randomised controlled trials assessing changes in HbA1c on a low carb versus a low fat diet, over half (8) significantly favour the low carb group and none significantly favour the low fat group [4].

Finally, we’ll consider the claim around erectile dysfunction (ED). It was implied that this condition could be fixed by adhering to the Simple as Fat programme. ED is a condition that is strongly linked with metabolic health issues such as obesity, diabetes and hypertension [5]. Recent research is showing that carbohydrate restriction can improve these metabolic issues [6]. However, making an explicit claim on ED is a reach, since it appears this has not been looked at as an outcome in these studies. The ASA may therefore be well-justified in criticising Simple as Fat for this claim.

What can we take away from this?

It is now well-known that a low carb lifestyle that focuses on real unprocessed food can impact positively on health and wellbeing. There is good evidence that obesity and type 2 diabetes specifically can be improved with this way of eating. Although the effect of low carb on other metabolic issues is being researched, there does not seem to be sufficient evidence to claim a direct benefit of the eating plan for erectile dysfunction. Likewise, careful terminology is needed when discussing improvements to type 2 diabetes, and so the word “cure” may be inappropriate at this stage.

The issue here may be largely one of careful wording and advertising etiquette, rather than a baseless eating plan. The claims made by Simple as Fat’s adverts are absolute and without caveat. This could sway people into thinking the plan will definitely result in these benefits for them. This is overlooking the built-in uncertainty that comes with Nutrition, as there is no such thing as a one-size-fits-all approach.

There is a growing consensus that too much refined carbohydrate and sugar in the diet is contributing to poor metabolic health and chronic disease. A low carbohydrate lifestyle is increasingly being shown to benefit health in many ways. However, in order to maintain a positive outlook in this area, it is important that any health claims are based on the best evidence and are not over-zealously or erroneously employed as a marketing tactic.



[1] NHS. (2018). How to diet. Available: https://www.nhs.uk/live-well/healthy-weight/how-to-diet/#how-to-lose-weight-the-healthy-way. Last accessed 25/02/2019.

[2] Public Health Collaboration. (2019). Randomised Controlled Trials Comparing Low-Carb Diets Of Less Than 130g Carbohydrate Per Day To Low-Fat Diets Of Less Than 35% Fat Of Total Calories. Available: https://phcuk.org/rcts/. Last accessed 25/02/2019.

[3] Saslow, L.R., Summers, C., Aikens, J.E. and Unwin, D.J., 2018. Outcomes of a Digitally Delivered Low-Carbohydrate Type 2 Diabetes Self-Management Program: 1-Year Results of a Single-Arm Longitudinal Study. JMIR diabetes, 3(3).

[4] Public Health Collaboration. (2019). Randomised Controlled Trials Comparing Low-Carb Diets Of Less Than 130g Carbohydrate Per Day To Low-Fat Diets Of Less Than 35% Fat Of Total Calories With Participants Living With Type 2 Diabetes. Available: https://phcuk.org/t2d/. Last accessed 25/02/2019.

[5] Shamloul, R. and Ghanem, H., 2013. Erectile dysfunction. The Lancet, 381(9861), pp.153-165.

[6] Bhanpuri, N.H., Hallberg, S.J., Williams, P.T., McKenzie, A.L., Ballard, K.D., Campbell, W.W., McCarter, J.P., Phinney, S.D. and Volek, J.S., 2018. Cardiovascular disease risk factor responses to a type 2 diabetes care model including nutritional ketosis induced by sustained carbohydrate restriction at 1 year: an open label, non-randomized, controlled study. Cardiovascular diabetology, 17(1), p.56.

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