Credibility of celebrity weight management blogs under question

With weight management discussions on social media being seen as highly influential, a new study by a team from the University of Glasgow in Scotland - assessing the underlying nutrition and weight management information provided by key UK social media influencers - suggests that most weight loss blogs are not a credible sources of advice.

The findings, recently presented at this year's European Congress on Obesity (ECO) in Glasgow, reveal that just one out of the nine most popular UK bloggers studied met the criteria for transparency, evidence-based references, trustworthiness and adherence to nutritional guidance, and bias.

Study lead author, Christina Sabbagh from the University of Glasgow explained "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."

The researchers conducted a comprehensive online search including the 'influence.co' website to identify the 14 most popular UK influencers with weight management blogs.

Influencers were selected on the basis of having more than 80,000 followers on at least one social media site, blue-tick verification (recognition for being influential in their field) on at least two social media sites, and an active weight management blog.

Five blogs were excluded because less than half of posts were not nutrition or physical activity-related.

Blogs by nine influencers published between May and June 2018 were analysed against 12 credibility indicators based on transparency, use of other resources, trustworthiness and adherence to nutritional criteria, and bias. These were set as yes (pass)/no (fail) questions, with an acceptable pass rate of more than 70% to ensure influencers who passed achieved most indicators.

Additionally, the 10 latest meal recipes from each blog were selected and analysed for energy, carbohydrates, protein, fat, saturated fat, fibre, sugar and salt content. Meals were evaluated against Public Health England's (PHE) 'One You' calorie reduction campaign and the UK Food Standards Agency's Traffic Light Scheme.

Analyses showed that seven influencers provided nutrition and weight management advice, while five failed to provide evidence-based references for nutrition claims or presented opinion as fact. Additionally, five influencers failed to provide a disclaimer, and just three suggested recipes that met the PHE calorie targets and traffic light criteria.

Interestingly, only the degree-qualified blogger, registered as a nutritionist with the UK Association for Nutrition, passed overall, with 83%. Another influencer, a medical doctor, did not pass the checklist. The lowest compliance (25%) was from an influencer without nutritional qualifications.

Sabbagh added "currently, no standards exist to assess the credibility of influencers' blogs.

"Given the popularity and impact of social media, all influencers should be required to meet accepted scientifically or medically justified criteria for the provision of weight management advice online."