Channel 4 has come under fire for Lose A Stone In 21 Days, with viewers slamming the show's 800 calorie diet.
Qualified doctor and journalist Michael Mosley described how he managed to reverse his Type 2 diabetes by sticking to a 5:2 diet - otherwise known as intermittent fasting.
Those who follow the diet typically eat normally for five days a week without thinking about restricting calories. On the other two days, you reduce your calorie intake to a quarter of your daily needs - about 500 calories per day for women, and 600 for men.
In the show, Mosley recommended that those who are looking to shed the pounds following lockdown could restrict to 800 calories per day for eight weeks, which would lead to an average weight loss of 20 pounds.
This is less than half of the recommended daily intake of 2,500 calories for men and 2,000 for women.
The NHS recommends consuming 500 to 600 less calories than you need each day in order to lose weight, adding that you should aim to lose one to two pounds a week.
Despite his good intentions, many viewers were horrified at Mosley's advice, taking to Twitter to share their disdain.
One viewer wrote: "800 calories a day is a starvation diet and should NOT be advocated in a television programme." Another said: "This 'expert advice' directly contradicts NHS healthy weight loss guidance. Absolute disgrace."
Another commented: "Not that I want to draw attention to it but I think we need to call out seriously irresponsible programming by @Channel4 last night - creating shame around gaining weight in lockdown in the midst of a global pandemic, putting people on 800 calorie diets."
Eating disorder charity Beat also criticised the show, with director of services Caroline Price telling the Independent it was 'incredibly worrying to see a national programme yet again promoting extreme weight loss and crash dieting'.
She went on: "The promise inherent in the title is likely to attract people suffering from or vulnerable to eating disorders and risks encouraging those affected to attempt the methods shown despite the damage this could cause."
Responding to the criticisms, a Channel 4 spokesperson told LADbible: "The series examines the evidenced link between Covid-19 and the very real threat it poses to those who have a BMI in the obese or overweight categories, as highlighted by a recent study led by Liverpool University and involving Imperial College London that found obese people are around 37 percent more likely to die if they catch Covid-19.
"All episodes clearly state that a short-term 800-1000 calorie diet is only suitable for people whose BMI puts them in the overweight or obese categories and that it should be done with proper medical supervision.
"The health and welfare of each contributor is of paramount importance to both Channel 4 and the production company and strict guidelines were followed before, during and after filming.
"A number of health checks were undertaken on contributors before they embarked on the regime and support is ongoing. The continuity announcer directed viewers to programme support information after the broadcast which is available at https://www.channel4.com/4viewers/help-support."
Channel 4 added that a substantiative response regarding the premise of the show and the support provided for the participants had been shared with Beat.