Words like “evidence-based” and “science-based” pepper the social-media profiles of dieticians and nutritionists keen to chasten unqualified health and lifestyle influencers for disseminating advice on healthy eating. So, no wonder they made hay with research – widely reported in the UK media – which claimed that social media influencers overwhelmingly give bad diet and fitness advice.

Just one of nine leading UK bloggers making weight management claims provided accurate and trustworthy information, contends the study presented at the European Congress on Obesity, at the University of Glasgow, in April 2019. No blogger met the calorie targets set by the UK government body Public Health England (PHE) and traffic light criteria.

The study’s lead author Christina Sabbagh said 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”.

The enthusiastic endorsement of the findings by dieticians and nutritionists reveals an underlying assumption that only official dietary guidelines and certified nutrition professionals can advise people on healthy eating – and that what they advise is the healthiest option.

But official healthy eating advice is not always aligned with science – and has resulted in arguably dubious healthy eating guidelines. For example:

• The Nutrient Profiling system, used by the UK Department of Health to determine which foods are healthier, classifies olive oil and butter as unhealthy foods. This resulted in a fresh grocery delivery service removing butter and bacon images from their advert on the London Underground (see NNB May 2019).
• Last year PHE launched a campaign to tackle obesity that focused on calorie intake, but placed barely any importance on including all the essential nutrients in the diet. This comes as more and more studies indicate that diet quality, not only quantity, is what helps people lose and manage their weight in the long run. (see NNB April 2018).
• The Eatwell guidelines, a set of dietary guidelines issued by PHE in 2016, almost halved the recommended daily intake of dairy products, using misleading statements like “dairy food can be high in fat and saturated fat” (see NNB April 2016).
• Nutri-Score, a front-of-package food labelling system introduced in France and Spain, billed salmon and olive oil as less healthy than French fries and zero-sugar soft drinks. (see NNB March 2019).

Online influencers posting about the next health food trends or diets that are a bit “out-there” are the bête noire of public health nutritionists. But on the other end of the spectrum, some official guidelines are still using dated science and providing a rigid, one-size-fits all framework. It comes as no surprise that the public is increasingly doing its own research, gleaning health advice from blogs and social media profiles of health influencers, and tailor-making their own diets.