January 17, 2025

expert reaction to Cochrane review on calorie labelling and food choices

A Cochrane review looks at calorie labelling and food choices.

Dr Sally Moore, Lecturer in Nutritional Science; Registered Dietitian; Registered Nutritionist (Public Health); Programme Leader Msci and BSc Nutrition and Lecturer, University of Leeds, said:

“This review study is thorough and of high quality and it takes into account the findings of global research on the impact of calorie labelling on consumers’ food selections in real-world, naturalistic laboratory, and laboratory settings.

“Given that larger takeaways, restaurants, and café food outlets in England have recently implemented legislation by providing calories (kcals) on their menus, it great to see that this new evidence review supports that there is some effect of this information on reducing the amount of energy consumers select.

“I would certainly encourage people to look at and use this information in the context of their nutritional needs – for example, for many people, a 600 calorie (kcal) sandwich delivers around a third of the energy needed per day (2000 kcal).

“However, given alone, the energy (calorie) content of food products does not tell us about other nutrients which we may need to consider in healthier eating, and often eat more of than recommended, including saturated fat, sugars and salt – which are provided alongside calorie information within UK Traffic Light nutrition labels as red (high), amber (medium) and green (low).  To further help consumers, I encourage policy makers to consider making traffic lights mandatory on UK food products.”

Dr Hilda Mulrooney, Reader in Nutrition & Health, London Metropolitan University, said:

“The press release reflects the findings particularly in relation to food selection (findings a small reduction of 11kcals or 1.8% energy reduction based on a 600kcal meal) and alcohol (inconclusive and inconsistent findings with poor quality of evidence).  In addition, the authors found an effect of calorie labelling on energy consumed (a small reduction of 35kcals or a 5.9% energy reduction, again based on a 600kcal meal).  The evidence for both findings in relation to food (i.e. calorie labelling leading to a small reduction in both selection and consumption of energy) was considered to be strong.

“This is a high quality and timely update of a previous review of the evidence.  A total of 25 studies were included, most of which were randomised control trials, the majority of which were carried out in real world settings.  Potential bias and study quality were evaluated.  The authors concluded that energy labelling on foods could result in small reductions in energy selected and consumed, with potential for a cumulative effect at the population level.  The findings for selection were derived from 16 studies which included 9850 participants, while those for consumption were based on 8 studies which included 2134 participants.  Given the strong links between poor diet and ill-health, these are important findings.  Tools such as nutrition labels provide guidance for consumers to help them make informed choices and to compare options for purchase and consumption, especially important given the high proportion of pre-packaged and pre-prepared foods in most diets.

“Nonetheless, the authors are clear that energy labelling alone will not ‘solve’ the problem of chronic disease, and further research is needed in particular to understand potential downsides, including disordered eating.”

Prof Tom Sanders, Professor emeritus of Nutrition and Dietetics, King’s College London, said:

“This report is a systematic review of calorie labelling on energy intake.  The strength of this review is that it included 25 studies in high income countries which were mainly randomized controlled trials.

“The main finding is a very small reduction in calorie intake of about 35 kcal per day (equivalent to 2 teaspoons of sugar or a half a pat of butter).  It is debatable whether such a small change would have any impact on body weight in the long term because there are compensatory physiological mechanisms that operate to maintain energy balance constant.  Weight gain normally occurs after large increases in calorie intake often over a short period (e.g. festive occasions such as Christmas).  Similarly, weight is only lost when there are prolonged reductions in calorie intake usually well in excess of 200 kcal per day.

“A further limitation is that it is well known that consumers get fatigue from calorie labelling in the long term particularly for regularly purchased products.  However, calorie labelling can be helpful for individuals who want to control their calorie intake particularly when consuming food outside the home.”

Prof Amanda Daley, Professor of Behavioural Medicine, Loughborough University, said:

“The authors have produced a well conducted report that shows calorie labelling helps to reduce the number of calories that the public consume, albeit by a small amount.  If we consider that most people eat three meals a day, these small amounts can add up and potentially contribute to reducing overweight in the population.  We need strategies that help the public to make healthy decisions about what they eat and based on the evidence from this report, calorie labelling has a role to play.”

Prof Keith Frayn, Emeritus Professor of Human Metabolism, University of Oxford, said:

“This research shows that calorie labelling brings about a small reduction in calorie selection, and, with less certainty, a larger reduction in calories consumed.  At least those effects are in a helpful direction.  But many of the studies analysed were of an experimental nature, for instance comparing two restaurants on a university campus, or randomisation of diners within one restaurant.  In the real world, there is a hope of additional benefit as food suppliers reduce the calorie content of their products to make them more attractive to discerning consumers.  There is some evidence for this occurring.  So the true impact of calorie labelling over time is likely, if anything, to be greater than observed here.  That makes calorie labelling a useful tool that will need to be employed along with other measures to help people reduce calorie consumption.”

Prof Richard Smith, Professor of Health Economics, University of Exeter, said:

“Reviews like this are robust research, but research in this area is moving fast, and a number of recent studies are not included.  A limitation of this type of review is that they look at one aspect of a problem in isolation.  Reducing consumption of obesogenic food will require a portfolio of policies, and the combined impact will be far greater than sum of the parts.  We need to be providing information, such as labelling, alongside policies on pricing and the choice environment, such as portion sizing, in a coordinated way if we are to really improve diets.”

‘Calorie (energy) labelling for changing selection and consumption of food or alcohol’ by Natasha Clarke et al. was published by Cochrane at 00:01 UK time on Friday 17 January 2025. 

DOI: 10.1002/14651858.CD014845.pub2

Declared interests

Dr Sally Moore: “I have no conflicts of interest.  Declaration: I am a Registered Dietitian (Health and Care Professions Council), and current Committee Member former Chair British Dietetic Association Public Health Nutrition Specialist Group.  I have previously conducted research in collaboration with consumers and industry with public research funding provided by UKRI Diet and Health Open Innovation Research Club (https://consumer-lab.bristol.ac.uk/project/finding-healthy-online-a-project-to-share-and-initiate-research-industrial-insight-on-how-online-supermarket-food-environments-can-support-healthier-more-sustainable-diets/).”

Dr Hilda Mulrooney: “I am a committee member of the British Dietetic Association Obesity Group; a committee member of the European Specialist Dietitians Network (Obesity) and a member of the Obesity Management Collaborative.  I am Council Member for Public Health of the Nutrition Society.  All of these positions are voluntary and unpaid.”

Prof Tom Sanders: “Member of the Science Committee British Nutrition Foundation.  Honorary Nutritional Director HEART UK.

Before my retirement from King’s College London in 2014, I acted as a consultant to many companies and organisations involved in the manufacture of what are now designated ultraprocessed foods.

I used to be a consultant to the Breakfast Cereals Advisory Board of the Food and Drink Federation.

I used to be a consultant for aspartame more than a decade ago.

When I was doing research at King’ College London, the following applied: Tom does not hold any grants or have any consultancies with companies involved in the production or marketing of sugar-sweetened drinks.  In reference to previous funding to Tom’s institution: £4.5 million was donated to King’s College London by Tate & Lyle in 2006; this funding finished in 2011. This money was given to the College and was in recognition of the discovery of the artificial sweetener sucralose by Prof Hough at the Queen Elizabeth College (QEC), which merged with King’s College London. The Tate & Lyle grant paid for the Clinical Research Centre at St Thomas’ that is run by the Guy’s & St Thomas’ Trust, it was not used to fund research on sugar. Tate & Lyle sold their sugar interests to American Sugar so the brand Tate & Lyle still exists but it is no longer linked to the company Tate & Lyle PLC, which gave the money to King’s College London in 2006.”

Prof Amanda Daley: “I have no direct conflicts to declare.  I have conducted food labelling studies myself and I have received government funding to conduct health based research.  I have never received any funding directly or indirectly from any food based industry partner.”

Prof Keith Frayn: “I have no commercial interests related to this topic.

I am the author of books on metabolism including ‘A Calorie is a Calorie’, Piatkus, Jan 2025.”

Prof Richard Smith: “No COI to declare.”