Only 1 out of 9 top bloggers studied offered credible nutrition/weight management advice

Embargo: 0001H UK time Tuesday 30 April

Weight management discussions on social media are very influential. But a new study assessing the underlying nutrition and weight management information provided by key UK social media influencers suggests that their blogs are not credible/trustworthy sources of advice.

The findings, being presented at this year’s European Congress on Obesity (ECO) in Glasgow, UK (28 April-1 May), 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.

“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”, says the study’s first author, Christina Sabbagh from the University of Glasgow in the UK. “This is potentially harmful, as these blogs reach such a wide audience.”

The researchers conducted a comprehensive online search including the ‘’ 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 [1]. 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 [2]. 

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. 

“Currently, no standards exist to assess the credibility of influencers’ blogs”, says Sabbagh. “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.”


Notes to editors:

[1] Transparency: Is the identity of the author always clear? Is there a professional statement present? Does the influencer respect and protect the privacy of blog readers? Are appropriate disclaimers regarding the use of the blog stated clearly?

Use of other resources: Are references cited on the blog? Are the references evidence-based?

Trustworthiness and adherence to nutritional criteria: Is the author qualified to provide weight management information? Has the influencer been awarded any quality credentials/badges from independent organisations? Do the recipes in the blog adhere to UK nutritional criteria (PHE/FSA)?

Bias: Does the blog clearly differentiate between advertisement and content? If the blog includes external advertising, is it disclosed? Does the influencer always make clear distinction between fact and opinion on their blog?

[2] and

The authors declare no conflicts of interest.

This press release is based on oral presentation OS8.06 at the European Congress on Obesity (ECO). All accepted abstracts have been extensively peer reviewed by the congress selection committee. There is no full paper at this stage, but the authors are happy to answer your questions. The research has not yet been submitted to a medical journal for publication.

For full abstract click here


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