Why you shouldn’t always trust weight-loss influencer advice

Why you shouldn’t always trust weight-loss influencer advice

Turning to social media for advice on everything from finding a reliable plumber to getting fit and losing weight has become the new norm. After all, it’s a quick and easy way to get recommendations and real facts from real people. When it comes to weight loss and fitness advice, many influencers have the before and after pics to prove that what they say works. The problem? New research shows that most weight management influencers actually don’t know what they're talking about.

The study1, which was recently presented at the European Congress on Obesity (ECO) in Glasgow2 shows that only one out of nine of UK's most popular health and weight loss bloggers was sharing solid, transparent, trustworthy, evidence-based nutritional information and advice.

Study selection criteria and evaluation checklist

The influencers selected for study had to meet the following criteria:

  • An excess of 80,000 followers on at least one social media platform
  • Blue-tick verification on two or more social media sites
  • Actively ran a weight management site or blog

Blog posts on their blogs between May and June 2018 were evaluated on 12 credibility indicators based on:

  • Transparency
  • Trustworthiness
  • Reference to other resources
  • Adherence to nutritional criteria and bias

This was done to determine whether the influencers had credible knowledge about nutrition and weight management and whether they shared the sources of this information or not, as well as whether or not opinion was stated as fact.

Researchers also examined the 10 most recently published recipes on each blog and evaluated the following present in each suggestion:

  • Energy content
  • Protein
  • Carbohydrates (including sugar)
  • Fat (including saturated fat)
  • Fibre
  • Sodium content

The recommended meals were then evaluated against the UK Food Standards Agency's Traffic Light Scheme3 and Public Health England's (PHE) 'One You' calorie reduction campaign4 in order to determine whether they met the required nutritional standards for calorie goals and nutritional content.

The acceptable pass rate for the overall analyses was set at 70%.

Weightmanagement influencers falling short

After evaluating these criteria, the researchers found that:

  • Five of the nine influencers did not provide evidence-based information and/or references for the nutritional claims they were making or presented their opinions as fact.
  • Only three influencer’s recipe suggestions met with the PHE calorie goals and traffic light criteria
  • An influencer who is a medical doctor did not pass
  • The lowest score, 25% was achieved by a weight management influencer with zero nutritional qualifications, who is still giving advice.

The only influencer who passed the checklist criteria, and with a score of 83%, was a degreed nutritionist registered with the UK Association for Nutrition.

Diet advice online

The experts weigh in

Kristin Kirkpatrick, a licensed, registered dietician and manager of the Cleveland Clinic Wellness Institute in Ohio is not surprised at the results as no degree or approval process is required to publish a blog or social media page.

She adds, however, that the findings frustrate her on two levels. First because dieticians and nutritionists go through many years of education and training to understand the complex mechanisms involved in the physiological functions of metabolism and digestion, yet thousands are listening to unqualified individuals. And secondly, the actual professionals and experts have to spend significant portions of their time disproving the myths propagated on social media.

According to Christina Sabbagh, the study’s lead author, MSC and policy and research assistant at Obesity Action Scotland, the findings are of great concern.  This is not only because potentially harmful information and advice is being offered by what has proven to be largely unqualified individuals, but also because this misinformation has the ability to spread to vast audiences, undermining the efforts of those providing evidence-based information.

Both experts agree that while social media platforms can be harnessed for good by influencers, the study indicates that they are more likely to facilitate the spread of inaccurate information. Sabbagh adds that as the online world is challenging when it comes to regulation and that some kind of verification scheme is necessary to ensure that an influencer has been properly vetted and is qualified to give nutritional or weight management advice.

Until this is a reality, however, it’s up to the audience to exercise discernment when deciding who to follow and listen to.

Is she qualified

Things to look out for before following an influencer

While it’s difficult to completely ascertain whether someone is the expert they claim to be online, there are a few things that you can check on:

  1. Qualifications: If an influencer is legitimately qualified by an accredited institution, they should display these qualifications and you should take the time to verify that they are true, either by searching online or contacting the institution in question.
  2. Transparency and credible references: Do they share their information sources? Do they make legitimate references to credible studies and use links and citations to do so?
  3. Disclosure: Do they mention business-interests in the products they recommend so that you are aware that they will make a commission if you click on the advertising or affiliate links mentioned on their site or social media account?
  4. Fact vs opinion: Do they make recommendations based on evidence-based fact (as published in well-designed, scientific studies).
  5. Attitudes to food/s: Does the influencer recommend eating according to the latest fad and severely restricting certain foods or cutting out entire food groups? Do they continually mention the use of certain supplements, products, pills, teas etc.
  6. Existence of people mentioned in testimonials: Can you find the people mentioned in testimonials on social media – i.e. are they real, contactable individuals?

While passing these checks can’t completely assure you that an influencer is 100% legitimate, they can help you to get an idea of who is more qualified to be giving the advice they are giving. After all, your health may just depend on it.



1. Study scrutinizes credibility of weight management blogs by most. EurekAlert!. https://www.eurekalert.org/pub_releases/2019-04/eaft-ssc042919.php. Published 2019. Accessed May 10, 2019.
2. 26Th European Congress On Obesity. Glasgow: European Association for the Study of Obesity; 2019:38. http://www.eco2019.org/provisionalProgramme.pdf. Accessed May 10, 2019.
3. Guide To Creating A Front Of Pack (Fop) Nutrition Label For Pre-Packed Products Sold Through Retail Outlets. Glasgow: Department of Health - Food Standards Agency; 2019.https://www.food.gov.uk/sites/default/files/media/document/fop-guidance_0.pdf. Accessed May 10, 2019.
4. EMBARGOED PHE PRESS RELEASE: 400-600-600 campaign launches to help adults tackle ‘calorie creep’. Phe-newsroom.prgloo.com. https://phe-newsroom.prgloo.com/news/embargoed-phe-press-release-400-600-600-campaign-launches-to-help-adults-tackle-calorie-creep. Published 2018. Accessed May 10, 2019.