In a series of tweets, Simple as Fat stated: “You can cure type 2 diabetes with real food NOT more pills” and insinuated that following the plan would offer “freedom from obesity and type 2 diabetes”.
A second post asked followers: “Has your Type 2 diabetes led to erectile dysfunction?” Before suggesting that by adhering to the programme, users could “fix it”.
Following the claims, the ASA criticised Simple as Fat for “discouraging essential treatment” for health conditions where medical advice should be sought.
The ASA said that any claims for weight-loss by an eating plan must be supported by rigorous trials, adding that it had seen no evidence to suggest the diet plan was effective as a weight-reduction method.
The advertising watchdog also pointed out that NHS advice on losing weight healthily recommends avoiding low-carbohydrate diets that are high in protein and fat.
“Many low-carbohydrate diets allow you to eat foods high in saturated fat, such as butter, cheese and meat,” the NHS states.
“Too much saturated fat can raise your cholesterol and increase your risk of heart disease and stroke.”
As a result of the ASA’s findings, Simple as Fat was ordered not to claim its diet plan was effective for weight loss.
It was also banned from stating or implying that users could overcome obesity, Type 2 diabetes or erectile dysfunction by following the plan.
In response to the order, radio presenter Jon Gaunt – who claims to have lost five stone on the plan – leapt to Simple as Fat’s defence by writing a post on its website.
The 57-year-old claimed that there are "thousands of people around the world who are living proof" that the plan works.
He also insisted that the diet does "help obese people to lose weight” and “gets Type 2 diabetic people off medication”.
You can find more information from the NHS about losing weight healthily and the danger of fad diets here.
The Independent has contacted Simple As Fat for comment.