Global Food Research: Will front-of-the-package warning labels change our eating habits?

The Global Food Research Program shares their perspective on targeting ultra-processed foods with front-of-the-package warning labels, which is the only impactful approach

In the past decade a major addition to our understanding of how the modern food supply is affecting adversely the risks of all Noncommunicable Diseases (NCDs), including obesity, diabetes, hypertension, major cancers – all of which are nutrition-related as either diet or obesity or both are major determinants. At the same time countries have begun to work out sets of regulations and laws to attempt to shift our diets toward reduced intakes of these foods and toward healthier eating. The Global Food Research Program at the University of North Carolina is a leading institution working to provide research related to the design of Front-of-the-Package food labelling and working with collaborators globally to evaluate them.

The significant health impact of ultra-processed food

A large and growing body of research has highlighted the large, significant impact of excessive consumption of ultra-processed food on the risks of noncommunicable diseases (NCDs), including obesity, diabetes, and hypertension. An important link was a random controlled trial with a crossover design (each person was his or her own control) that a highly respected team of researchers at the US National Institutes of Health (NIH) conducted in 2019.1 The researchers fed normal-weight adults a diet of real food for two weeks and a diet of ultra-processed food for another two weeks. While consuming the real food the adults lost 0.9 kilograms, but while consuming the ultra-processed food the same adults gained 0.9 kilograms. Biomarkers for diabetes, hypertension, and hyperlipidemia, among others, increased equally significantly with the ultra-processed food diet. Each group started with one diet regimen and then shifted to the other.1

The 2019 NIH trial is important, as previously all the studies discussed below were observational and therefore focused on subsequent health risks according to the amount of ultra-processed food in people’s diets. Although these studies were controlled for a long list of potential confounders, such as physical activity and smoking, residual confounding never can be discarded. This 2019 NIH study put all subjects into a controlled food environment for a month.

The researchers provided each group foods with the same distributions of fiber, protein, carbohydrates, fats, and total energy. However, while ultra-processed beverages can lower energy density and total energy, all ultra-processed foods are higher in energy density than real foods. The members of the two groups were allowed to eat ad libitum or the amount they wanted. As a result, the same individuals consumed 500 kilocalories more when they were in the ultra-processed food group than when they were in the real food group, which is important. Whether the mechanism involved is hyper-palatability, energy density, or both requires further study.

This NIH work is supported by 19 wide-ranging cohort studies in Europe, the United States, Brazil, and elsewhere. These studies, mainly of adults but a few of children, link increased proportions of ultra-processed food in the diet with increased risks of obesity; many measures of cardiovascular disease (CVD), including diabetes, hypertension, overall CVD, and CVD mortality; cancer; and total mortality.2-18

The rapid growth in ultra-processed food consumption across the globe

Increasingly, pre-packaged foods and beverages are readily available in virtually every community across all parts of the globe, regardless of income level or population density.18-23 Combined with aggressive marketing of these products, this availability has dramatically affected the way people eat in many countries, resulting in less healthy diets.24-27

Many prepackaged foods are processed with high levels of added sugars, sodium, saturated fats, and refined carbohydrates.27-31 Research has connected these nutrients of concern to increased obesity and chronic nutrition-related diseases.24,32-36 The emerging evidence indicates that malnourished infants and preschoolers are fed these processed foods and beverages. Recent studies associate ultra-processed food with reduced length for age.37

The 2019 A. M. Pries et al. study is the only one that examines infant consumption of any ultra-processed food aside from infant formula, which fits into a different category but is also ultra-processed. We need longitudinal studies on cohorts with more recent full dietary intake data to reflect the increasing shift in ‘low- and middle-income countries’ infant diets toward ultra-processed food.28-30,37-39

Front-of-the-package warning labels empower informed choices:

Consumers need a clear and easy way to make healthier choices among the array of available products.

Shoppers prefer simple front-of-the-package (FOP) labels that are immediately visible and quickly evaluated.40,41 Labels that minimise effort allow customers to rapidly determine which products are healthier and thereby actually increase the intention to purchase a healthy product or, conversely, decrease the intention to purchase an unhealthy product.42-46

Among the several labelling approaches that have been devised, simple negative warning labels that identify unhealthy products are most effective in discouraging junk and ultra-processed food choices.47

Why not a healthfulness score or a traffic light?

When compared to other FOP labels, FOP nutrient warning labels may have different effects on consumer behaviours and ultimately on diet-related health outcomes. For example, some FOP labelling systems, such as Nutriscore or Australia’s Health Star Ratings, create summary indexes of multiple nutrients, including nutrients of concern, beneficial nutrients, or beneficial ingredients, to present a product’s overall nutritional profile on a continuum from least to most “healthy.” In these systems, the levels of nutrients of concern to the consumer are not clear, and often one nutrient can offset another in a way that impacts NCD concerns, for example, a sugar-sweetened beverage (SSB) fortified with vitamin C.

Other FOP label schemes, like the traffic light label, that colour-code multiple nutrients convey complex and sometimes contradictory information, such as a product high in one nutrient of concern but low in another, requiring consumers to evaluate all the information to come to an assessment of overall healthfulness. A consumer can become confused when a nutrient of concern, say sugar, is offset by another, say sodium. In contrast, nutrient warnings are binary, focused on nutrients of concern, and signal to consumers the presence or absence of high levels of these nutrients of concern.

These distinctions may have important implications for how labelling systems influence consumer behaviour. For example, FOP labelling systems that do not call attention to nutrients of concern or present potentially conflicting information may be more likely to encourage consumers to choose the “healthier” option among still unhealthy products rather than the proven healthy options.

Chilean studies evaluating the first year of required warning label implementation are emerging. The first study on focus groups of lower- and middle-income mothers suggests profound changes in food purchasing linked not only with the knowledge mothers gained from these labels but also with children telling their mothers not to purchase unhealthy products.48,49 We anticipate that future studies will show large changes in purchases of key unhealthy foods with warning labels.

Another Chilean evaluation of the impact of phase 1 of the implementation of the SSB warning label found that in the first year SSB purchases declined 23.7% in millilitre per capita per day.50 The phase 2 and 3 cutoffs will affect higher proportions of unhealthy foods and beverages. Chile was the world’s top country in per capita SSB consumption at the time the law went into effect.

What experiments have already been done?

Experiments in many countries with FOP warning labels on SSBs linked warning labels with decreased purchases of SSBs, decreased perceptions of their healthfulness,51,52 and decreased purchasing intent.51-53

A 2017 study comparing FOP warning labels to the industry-endorsed guidelines for daily allowance (GDA) and traffic light label systems found that warning labels were better able to help consumers correctly identify products high in unhealthy nutrients and that consumers perceived products bearing warning labels as less healthy than the same products featuring GDA or traffic light labels.54

Another 2017 study in Uruguay comparing children’s perceptions of food products with warning versus traffic light labels found that warning labels had greater relative impacts on children’s food choices compared to the traffic light system.55

Studies using eye-tracking technology to evaluate the influence of nutritional warnings alongside GDA labels have found that nutrient-based warning labels attract consumers’ attention and help them more quickly and easily identify whether a product is unhealthy.56,57

The only traffic light label study to show a positive impact combined financial incentives with the traffic light system.58 No study has shown that Nutriscore, GDA, or traffic light labels significantly impact food or beverage purchases.

A recent in-depth review of all FOP warning label systems highlights the critical value of warning labels in reaching consumers and impacting their behaviours.59 This scoping review found that many experimental studies of FOP nutrient warning labels focused on outcomes, such as comprehension and behavioural intention, but that considerable gaps in the evidence remain, particularly in the areas of negative affect and social interactions, precluding a clear understanding of the pathway through which nutrient-based FOP warnings change behaviour.

The studies found that nutrient-based FOP warnings visually attracted consumers, were easy to understand, helped consumers identify products high in nutrients of concern, and discouraged consumers from purchasing unhealthy products but do not contain as much information as other FOP labelling systems.

Please note: This is a commercial profile

1. Hall KD (2019 ) Ultra-processed diets cause excess calorie intake and weight gain: A one-month inpatient randomised controlled trial of ad libitum food intake. Cell Matabolism 30: 1-10.

2. Lawrence MA, Baker PI (2019) Ultra-processed food and adverse health outcomes. BMJ 365: l2289.
3. Rico-Campà A, Martínez-González MA, Alvarez-Alvarez I, de Deus Mendonça R, de la Fuente-Arrillaga C, et al. (2019) Association between consumption of ultra-processed foods and all cause mortality: SUN prospective cohort study. bmj 365: l1949.
4. Srour B, Fezeu LK, Kesse-Guyot E, Allès B, Méjean C, et al. (2019) Ultra-processed food intake and risk of cardiovascular disease: prospective cohort study (NutriNet-Santé). bmj 365: l1451.
5. Fiolet T, Srour B, Sellem L, Kesse-Guyot E, Allès B, et al. (2018) Consumption of ultra-processed foods and cancer risk: results from NutriNet-Santé prospective cohort. bmj 360: k322.
6. Rauber F, Campagnolo P, Hoffman DJ, Vitolo MR (2015) Consumption of ultra-processed food products and its effects on children’s lipid profiles: a longitudinal study. Nutrition, Metabolism and Cardiovascular Diseases 25: 116-122.
7. Mendonça RdD, Pimenta AM, Gea A, de la Fuente-Arrillaga C, Martinez-Gonzalez MA, et al. (2016) Ultraprocessed food consumption and risk of overweight and obesity: the University of Navarra Follow-Up (SUN) cohort study. The American journal of clinical nutrition 104: 1433-1440.
8. Adjibade M, Julia C, Allès B, Touvier M, Lemogne C, et al. (2019) Prospective association between ultra-processed food consumption and incident depressive symptoms in the French NutriNet-Santé cohort. BMC medicine 17: 78.
9. Costa C, Rauber F, Leffa P, Sangalli C, Campagnolo P, et al. (2019) Ultra-processed food consumption and its effects on anthropometric and glucose profile: A longitudinal study during childhood. Nutrition, Metabolism and Cardiovascular Diseases 29: 177-184.
10. Cunha DB, da Costa THM, da Veiga GV, Pereira RA, Sichieri R (2018) Ultra-processed food consumption and adiposity trajectories in a Brazilian cohort of adolescents: ELANA study. Nutrition & diabetes 8: 28.
11. Gómez-Donoso C, Sánchez-Villegas A, Martínez-González MA, Gea A, de Deus Mendonça R, et al. (2019) Ultra-processed food consumption and the incidence of depression in a Mediterranean cohort: The SUN Project. European journal of nutrition: 1-11.
12. Kim H, Hu EA, Rebholz CM (2019) Ultra-processed food intake and mortality in the USA: Results from the Third National Health and Nutrition Examination Survey (NHANES III, 1988–1994). Public health nutrition 22: 1777-1785.
13. Mendonça RdD, Lopes ACS, Pimenta AM, Gea A, Martinez-Gonzalez MA, et al. (2017) Ultra-processed food consumption and the incidence of hypertension in a Mediterranean cohort: the Seguimiento Universidad de Navarra Project. American journal of hypertension 30: 358-366.
14. Rohatgi KW, Tinius RA, Cade WT, Steele EM, Cahill AG, et al. (2017) Relationships between consumption of ultra-processed foods, gestational weight gain and neonatal outcomes in a sample of US pregnant women. PeerJ 5: e4091.
15. Rauber F, da Costa Louzada ML, Steele E, Millett C, Monteiro CA, et al. (2018) Ultra-processed food consumption and chronic non-communicable diseases-related dietary nutrient profile in the UK (2008–2014). Nutrients 10: 587.
16. Sandoval-Insausti H, Blanco-Rojo R, Graciani A, López-García E, Moreno-Franco B, et al. (2019) Ultra-processed Food Consumption and Incident Frailty: A Prospective Cohort Study of Older Adults. The Journals of Gerontology: Series A.
17. Schnabel L, Kesse-Guyot E, Allès B, Touvier M, Srour B, et al. (2019) Association between ultraprocessed food consumption and risk of mortality among middle-aged adults in France. JAMA internal medicine 179: 490-498.
18. Vandevijvere S, Jaacks LM, Monteiro CA, Moubarac JC, Girling‐Butcher M, et al. (2019) Global trends in ultraprocessed food and drink product sales and their association with adult body mass index trajectories. Obesity Reviews.
19. Reardon T, Timmer CP, Barrett CB, Berdegue JA (2003) The rise of supermarkets in Africa, Asia, and Latin America. American Journal of Agricultural Economics 85: 1140-1146.
20. Reardon T, Timmer CP, Minten B (2012) Supermarket revolution in Asia and emerging development strategies to include small farmers. Proceedings of the National Academy of Sciences 109: 12332-12337.
21. Popkin BM (2014) Nutrition, agriculture and the global food system in low and middle income countries. Food Policy 47: 91-96.
22. Zhou Y, Du S, Su C, Zhang B, Wang H, et al. (2015) The food retail revolution in China and its association with diet and health. Food Policy 55: 92-100.
23. Popkin BM, Reardon T (2018) Obesity and the food system transformation in Latin America. Obesity Reviews.
24. Anand SS, Hawkes C, de Souza RJ, Mente A, Dehghan M, et al. (2015) Food Consumption and its Impact on Cardiovascular Disease: Importance of Solutions Focused on the Globalized Food SystemA Report From the Workshop Convened by the World Heart Federation. Journal of the American College of Cardiology 66: 1590-1614.
25. Imamura F, Micha R, Khatibzadeh S, Fahimi S, Shi P, et al. (2015) Dietary quality among men and women in 187 countries in 1990 and 2010: a systematic assessment. The Lancet Global Health 3: e132-e142.
26. Popkin B, Adair L, Ng S (2012) Global nutrition transition and the pandemic of obesity in developing countries. Nutrition Reviews 70: 3-21.
27. Monteiro CA, Moubarac JC, Cannon G, Ng SW, Popkin B (2013) Ultra‐processed products are becoming dominant in the global food system. Obesity reviews 14: 21-28.
28. Pries AM, Huffman SL, Mengkheang K, Kroeun H, Champeny M, et al. (2016) High use of commercial food products among infants and young children and promotions for these products in Cambodia. Maternal & Child Nutrition 12: 52-63.
29. Pries AM, Huffman SL, Adhikary I, Upreti SR, Dhungel S, et al. (2016) High consumption of commercial food products among children less than 24 months of age and product promotion in Kathmandu Valley, Nepal. Maternal & Child Nutrition 12: 22-37.
30. Feeley AB, Ndeye Coly A, Sy Gueye NY, Diop EI, Pries AM, et al. (2016) Promotion and consumption of commercially produced foods among children: situation analysis in an urban setting in Senegal. Maternal & child nutrition 12: 64-76.
31. Marriott BM, Campbell L, Hirsch E, Wilson D (2007) Preliminary data from demographic and health surveys on infant feeding in 20 developing countries. The Journal of nutrition 137: 518S-523S.
32. World Health Organization (2015) Guideline: Sugar intake for adults and children. In: WHO Department of Nutrition for Health and Development (NHD), editor. Geneva: WHO. pp. 50.
33. World Cancer Research Fund International (2015) Curbing global sugar consumption: Effective food policy actions to help promote healthy diets and tackle obesity.
34. U.S. Department of Health and Human Services, US Department of Agriculture (2015) Scientific Report of the 2015 Dietary Guidelines Advisory Committee. Washington, DC.
35. Report of a WHO Forum and Technical Meeting (2006) Reducing Salt Intake in Populations.
36. WHO/FAO (2003) Diet, nutrition and the prevention of chronic diseases: Report of a joint WHO/FAO expert consultation. Technical Report Series 916.
37. Pries AM, Rehman AM, Filteau S, Sharma N, Upadhyay A, et al. (2019) Unhealthy Snack Food and Beverage Consumption Is Associated with Lower Dietary Adequacy and Length-for-Age z-Scores among 12–23-Month-Olds in Kathmandu Valley, Nepal. The Journal of Nutrition.
38. Pries AM, Filteau S, Ferguson EL (2019) Snack food and beverage consumption and young child nutrition in low- and middle-income countries: A systematic review. Maternal & Child Nutrition 15: e12729.
39. Vitta BS, Benjamin M, Pries AM, Champeny M, Zehner E, et al. (2016) Infant and young child feeding practices among children under 2 years of age and maternal exposure to infant and young child feeding messages and promotions in Dar es Salaam, Tanzania. Maternal & Child Nutrition 12: 77-90.
40. Mandle J, Tugendhaft A, Michalow J, Hofman K (2015) Nutrition labelling: a review of research on consumer and industry response in the global South. Global Health Action 8: 10.3402/gha.v3408.25912.
41. Vyth EL, Steenhuis IH, Vlot JA, Wulp A, Hogenes MG, et al. (2010) Actual use of a front-of-pack nutrition logo in the supermarket: consumers’ motives in food choice. Public Health Nutr 13: 1882-1889.
42. Roodenburg A, Popkin B, Seidell J (2011) Development of international criteria for a front of package food labelling system: the International Choices Programme. Eur J Clin Nutr 65: 1190.
43. Wartella EA, Lichtenstein AH, Boon CS, Editors, editors (2010) Examination of Front-of-Package Nutrition Rating Systems and Symbols: Phase 1 Report. Washington DC: National Academy Press. 140 p.
44. Feunekes GIJ, Gortemaker IA, Willems AA, Lion R, van den Kommer M (2008) Front-of-pack nutrition labelling: Testing effectiveness of different nutrition labelling formats front-of-pack in four European countries. Appetite 50: 57-70.
45. Hamlin RP, McNeill LS, Moore V (2014) The impact of front-of-pack nutrition labels on consumer product evaluation and choice: an experimental study. Public health nutrition: 1-9.
46. Ares G, Varela F, Machin L, Antúnez L, Giménez A, et al. (2018) Comparative performance of three interpretative front-of-pack nutrition labelling schemes: Insights for policy making. Food Quality and Preference.
47. Corvalan C, Reyes M, Garmendia ML, Uauy R (2013) Structural responses to the obesity and non-communicable diseases epidemic: the Chilean Law of Food Labeling and Advertising. Obesity Reviews 14: 79-87.
48. Corvalán C, Reyes M, Garmendia ML, Uauy R (2019) Structural responses to the obesity and non-communicable diseases epidemic: Update on the Chilean law of food labelling and advertising. Obesity Reviews 20: 367-374.
49. Correa T, Fierro C, Reyes M, Dillman Carpentier FR, Taillie LS, et al. (2019) Responses to the Chilean law of food labeling and advertising: exploring knowledge, perceptions and behaviors of mothers of young children. International Journal of Behavioral Nutrition and Physical Activity 16: 21.
50. Taillie LS, C. A., Reyes M, Popkin BM, Corvalan C. (2020). “Evaluating the impact of Chile’s front-of-package warning label, marketing, and school food policies on sugar-sweetened beverage purchases: an observational study. .” PLOS Medicine 17(2): e1003015.
51. Roberto CA, Wong D, Musicus A, Hammond D (2016) The Influence of Sugar-Sweetened Beverage Health Warning Labels on Parents’ Choices. Pediatrics.
52. Taillie Lindsey S HM, Popkin Barry M, Ng SW, Murukutla N., (2020) Experimental studies of front-of-package nutrient warning labels on sugar-sweetened beverages and ultra-processed foods: A scoping review. Nutrients.
53. Bollard T, Maubach N, Walker N, Ni Mhurchu C (2016) Effects of plain packaging, warning labels, and taxes on young people’s predicted sugar-sweetened beverage preferences: an experimental study. International Journal of Behavioral Nutrition and Physical Activity 13: 95.
54. Arrúa A, Machín L, Curutchet MR, Martínez J, Antúnez L, et al. (2017) Warnings as a directive front-of-pack nutrition labelling scheme: comparison with the Guideline Daily Amount and traffic-light systems. Public Health Nutrition 20: 2308-2317.
55. Arrúa A, Curutchet MR, Rey N, Barreto P, Golovchenko N, et al. (2017) Impact of front-of-pack nutrition information and label design on children’s choice of two snack foods: Comparison of warnings and the traffic-light system. Appetite 116: 139-146.
56. Centurión M, Machín L, Ares G (2019) Relative Impact of Nutritional Warnings and Other Label Features on Cereal Bar Healthfulness Evaluations. Journal of Nutrition Education and Behavior.
57. Popova L, Nonnemaker J, Taylor N, Bradfield B, Kim A (2019) Warning Labels on Sugar-sweetened Beverages: An Eye Tracking Approach. American Journal of Health Behavior 43.
58. Franckle RL, Levy DE, Macias-Navarro L, Rimm EB, Thorndike AN (2018) Traffic-light labels and financial incentives to reduce sugar-sweetened beverage purchases by low-income Latino families: a randomised controlled trial. Public Health Nutr: 1-9.
59. Taillie LS, Marissa G. Hall, Barry M. Popkin, Shu Wen Ng, Nandita Murukutla (2020) Experimental studies of front-of-package nutrient warning labels on sugar-sweetened beverages and ultra-processed foods: A scoping review Nutrients.

Read Profile

Barry M Popkin

Jr. Distinguished Professor

Gillings School of Global Public Health

Phone: +1 (919) 962 6139

Email: POPKIN@UNC.EDU

Website: Visit Website

Twitter: Follow on Twitter