People wanting to lose weight should stay away from bloggers on social media who claim to have the latest diet fix, researchers say.
A new study presented at the European Congress on Obesity in Glasgow found that just one out of nine of the most popular UK bloggers making weight management claims actually provided accurate and trustworthy information.
A team from the University of Glasgow examined whether health and diet claims made by influencers were transparent, included evidence-based references, were trustworthy and were nutritionally sound.
The team also looked at the role of bias in what was put online.
Lead author Christina Sabbagh said: “We found that the majority of the blogs could not be considered credible sources of weight management information, as they often presented opinion as fact and failed to meet UK nutritional criteria.
“This is potentially harmful, as these blogs reach such a wide audience.”
Researchers selected bloggers for the study based on those who had more than 80,000 followers on at least one social media site, those who had been verified with a “blue tick” from sites such as Twitter, and who had an active weight management blog.
The team analysed blogs by nine influencers published between May and June 2018 and scored them against 12 criteria to show credibility.
Bloggers were regarded as having “passed” the test if they met 70% or more of the criteria.
Researchers also examined the 10 latest meal recipes from each blog for energy content, carbohydrates, protein, fat, saturated fat, fibre, sugar and salt content.
The results showed that some bloggers failed on key things, with five presenting opinion as fact or failing to provide evidence-based references for nutritional claims.
Five failed to provide a disclaimer, and, when meals were examined against Public Health England (PHE) calorie targets and traffic light criteria, no blogger met these criteria.
Of the advice-based blogs, only one by a registered nutritionist with a degree passed overall, with 75%.
The lowest compliance (25%) was from an influencer without nutritional qualifications.
The authors concluded: “Social media influencers’ blogs are not credible resources for weight management.
“Popularity and impact of social media in the context of the obesity epidemic suggests all influencers should be required to meet accepted scientifically or medically justified criteria for the provision of weight management advice online.”
Tam Fry, chairman of the National Obesity Forum, said: “This study adds to the evidence of the destructive power of social media.
“Any Tom, Dick or Harry can take to the ether, post whatever they like and be believed by their followers.
“Particularly unfortunate is that the genie is now firmly out of the bottle and getting these bloggers to conform to ‘standards’, though desirable, will be nigh impossible.
“The bloggers will defend their right to freedom of speech to the hilt but publishing junk advice is indefensible.”