Impact of health warning labels and calorie labels on selection and purchasing of alcoholic and non-alcoholic drinks: A randomized controlled trial

Calorie (energy) labelling for changing selection and consumption of food or alcohol

BACKGROUND

Overconsumption of food and consumption of any amount of alcohol increases the risk of non-communicable diseases. Calorie (energy) labelling is advocated as a means to reduce energy intake from food and alcoholic drinks. However, there is continued uncertainty about these potential impacts, with a 2018 Cochrane review identifying only a small body of low-certainty evidence. This review updates and extends the 2018 Cochrane review to provide a timely reassessment of evidence for the effects of calorie labelling on people's selection and consumption of food or alcoholic drinks.

OBJECTIVES

- To estimate the effect of calorie labelling for food (including non-alcoholic drinks) and alcoholic drinks on selection (with or without purchasing) and consumption. - To assess possible modifiers - label type, setting, and socioeconomic status - of the effect of calorie labelling on selection (with or without purchasing) and consumption of food and alcohol.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PsycINFO, five other published or grey literature databases, trial registries, and key websites, followed by backwards and forwards citation searches. Using a semi-automated workflow, we searched for and selected records and corresponding reports of eligible studies, with these searches current to 2 August 2021. Updated searches were conducted in September 2023 but their results are not fully integrated into this version of the review.

SELECTION CRITERIA

Eligible studies were randomised controlled trials (RCTs) or quasi-RCTs with between-subjects (parallel group) or within-subjects (cross-over) designs, interrupted time series studies, or controlled before-after studies comparing calorie labelling with no calorie labelling, applied to food (including non-alcoholic drinks) or alcoholic drinks. Eligible studies also needed to objectively measure participants' selection (with or without purchasing) or consumption, in real-world, naturalistic laboratory, or laboratory settings.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion and extracted study data. We applied the Cochrane RoB 2 tool and ROBINS-I to assess risk of bias in included studies. Where possible, we used (random-effects) meta-analyses to estimate summary effect sizes as standardised mean differences (SMDs) with 95% confidence intervals (CIs), and subgroup analyses to investigate potential effect modifiers, including study, intervention, and participant characteristics. We synthesised data from other studies in a narrative summary. We rated the certainty of evidence using GRADE.

MAIN RESULTS

We included 25 studies (23 food, 2 alcohol and food), comprising 18 RCTs, one quasi-RCT, two interrupted time series studies, and four controlled before-after studies. Most studies were conducted in real-world field settings (16/25, with 13 of these in restaurants or cafeterias and three in supermarkets); six studies were conducted in naturalistic laboratories that attempted to mimic a real-world setting; and three studies were conducted in laboratory settings. Most studies assessed the impact of calorie labelling on menus or menu boards (18/25); six studies assessed the impact of calorie labelling directly on, or placed adjacent to, products or their packaging; and one study assessed labels on both menus and on product packaging. The most frequently assessed labelling type was simple calorie labelling (20/25), with other studies assessing calorie labelling with information about at least one other nutrient, or calories with physical activity calorie equivalent (PACE) labelling (or both). Twenty-four studies were conducted in high-income countries, with 15 in the USA, six in the UK, one in Ireland, one in France, and one in Canada. Most studies (18/25) were conducted in high socioeconomic status populations, while six studies included both low and high socioeconomic groups, and one study included only participants from low socioeconomic groups. Twenty-four studies included a measure of selection of food (with or without purchasing), most of which measured selection with purchasing (17/24), and eight studies included a measure of consumption of food. Calorie labelling of food led to a small reduction in energy selected (SMD -0.06, 95% CI -0.08 to -0.03; 16 randomised studies, 19 comparisons, 9850 participants; high-certainty evidence), with near-identical effects when including only studies at low risk of bias, and when including only studies of selection with purchasing. There may be a larger reduction in consumption (SMD -0.19, 95% CI -0.33 to -0.05; 8 randomised studies, 10 comparisons, 2134 participants; low-certainty evidence). These effect sizes suggest that, for an average meal of 600 kcal, adults exposed to calorie labelling would select 11 kcal less (equivalent to a 1.8% reduction), and consume 35 kcal less (equivalent to a 5.9% reduction). The direction of effect observed in the six non-randomised studies was broadly consistent with that observed in the 16 randomised studies. Only two studies focused on alcoholic drinks, and these studies also included a measure of selection of food (including non-alcoholic drinks). Their results were inconclusive, with inconsistent effects and wide 95% CIs encompassing both harm and benefit, and the evidence was of very low certainty.

AUTHORS' CONCLUSIONS

Current evidence suggests that calorie labelling of food (including non-alcoholic drinks) on menus, products, and packaging leads to small reductions in energy selected and purchased, with potentially meaningful impacts on population health when applied at scale. The evidence assessing the impact of calorie labelling of food on consumption suggests a similar effect to that observed for selection and purchasing, although there is less evidence and it is of lower certainty. There is insufficient evidence to estimate the effect of calorie labelling of alcoholic drinks, and more high-quality studies are needed. Further research is needed to assess potential moderators of the intervention effect observed for food, particularly socioeconomic status. Wider potential effects of implementation that are not assessed by this review also merit further examination, including systemic impacts of calorie labelling on industry actions, and potential individual harms and benefits.

Effectiveness of alcohol warning labels for at-risk groups and the general public: A policy-informing randomized experiment in Chile

OBJECTIVE

The World Health Organization recommends using health-risk warnings on alcoholic beverages. This study examines the impact of separate or combined warning labels for at-risk groups and the general population on alcohol purchase decisions.

METHODS

In 2022, 7758 adults who consumed alcohol or were pregnant/lactating women (54.0 % female, mean age = 40.6 years) were presented with an online store's beverage section and randomly assigned to one of six warning labels in a between-subjects experimental design: no-warning, pregnant/lactating, drinking-driving, general cancer risk, combined warnings, and assorted warnings across bottles. The main outcome, the intention to purchase an alcoholic vs. non-alcoholic beverage, was examined with adjusted risk differences using logistic regressions.

RESULTS

Participants exposed to the general cancer risk warning decreased their alcoholic choices by 10.4 percentage points (pp.) (95 % CI [-0.139, -0.069], p < 0.001, OR = 0.561), while those in the pregnancy/lactation warning condition did it by 3.8 pp. (95 % CI [-0.071, -0.005], p = 0.025, OR = 0.806). The driving-drinking warning had no significant effect. Participants exposed to the combined warnings label, or the assorted warnings reduced alcohol purchase decisions by 6.1 pp. (95 % CI [-0.095, -0.028], p < 0.001, OR = 0.708) and 4.3 pp. (95 % CI [-0.076, -0.010], p = 0.011, OR = 0.782), respectively. Cancer warning outperformed other labels and was effective for subgroups such as pregnant/lactating women, young adults, and low-income individuals.

CONCLUSIONS

General cancer risk warnings are more effective at reducing alcohol purchase decisions compared to warning labels for specific groups or labels using multiple warnings. In addition to warning labels, other policies should be considered for addressing well-known alcohol-related risks (e.g., drinking and driving).

Potential impact of alcohol calorie labelling on the attitudes and drinking behaviour of hazardous and low-risk drinkers in England: a national survey

OBJECTIVES

We investigated the hypothetical impact of mandatory alcohol calorie labelling, comparing non-drinkers, low-risk and hazardous drinkers in terms of attitudes, knowledge about calorie content and hypothetical behaviour changes should labelling be introduced.

DESIGN

Cross-sectional national telephone survey.

SETTING

Community-dwelling adults in England between November 2022 and January 2023.

PARTICIPANTS

Data were collected from 4683 adults >18 years, of whom 24.7% were non-drinkers; 77.6% of alcohol drinkers were categorised as low-risk and 22.4% as hazardous drinkers according to the Alcohol Use Disorders Identification Test questionnaire.

PRIMARY OUTCOME MEASURES

Attitudes to alcohol calorie labelling in shops and supermarkets and in hospitality venues, knowledge of the calorie content of alcoholic beverages (beer, wine, cider and spirits) and changes in drinking practices if calorie labelling was introduced.

RESULTS

Comparisons were made between non-drinkers, low-risk drinkers and hazardous drinkers, with analyses adjusted for age, gender, ethnicity, socioeconomic status and education. Attitudes to calorie labelling were generally positive, but were less favourable among alcohol drinkers than non-drinkers. Hazardous drinkers were more accurate in their estimations of the calorie content of wine, cider and spirits than non-drinkers (p<0.0001). Overall, 46.4% of drinkers indicated that they would change their drinking patterns if calorie labelling was introduced, and this response was more common among hazardous than low-risk drinkers (OR=1.43, 95% CI 1.199 to 1.699), adjusting for age, gender, ethnicity, socioeconomic status and education. Compared with low-risk drinkers, hazardous drinkers stated that they would be more likely to drink fewer alcoholic beverages, to drink alcohol less often, to choose lower calorie drinks and to do more exercise (adjusted OR 1.27, 1.009 to 1.606).

CONCLUSIONS

A sizeable proportion of hazardous drinkers indicated that they would change their consumption practices if mandatory calorie labelling was introduced. Promoting more positive attitudes to calorie labelling might lead to stronger intentions to reduce consumption. Mandatory calorie labelling of alcoholic beverages may make a modest contribution to energy intake and the maintenance of health weight, particularly among heavier drinkers.

Two online randomised controlled trials examining effects of alcohol calorie labelling on hypothetical ordering of calories from alcohol and food

BACKGROUND

Providing calorie information for alcoholic beverages is a potential public-health intervention which may serve to reduce alcohol use but also prevalence of overweight/obesity. Equivocal evidence has been found for the effectiveness of alcohol calorie information at reducing drinking intentions as well as purchasing and consumption. However, the extent at which calorie information 'on-trade' will impact consumer behaviour for both alcohol and food consumption has not been investigated.

AIMS

(1) To examine the presence of alcohol calorie labelling for hypothetical purchasing of alcohol and food in typical UK restaurant scenarios. (2) To determine the characteristics of individuals who will be likely to choose to view alcohol calorie labels.

METHODS

Two online randomised control trials using a hypothetical menu selection. In experiment one (N = 325) participants were randomised to the presence or absence of alcohol calorie labels. In experiment two (N = 1081) individuals were randomised to alcohol calorie labels absent or the choice to view alcohol calorie labels. The primary outcome for each study was calories ordered from alcoholic beverages.

RESULTS

There was no evidence that the presence of alcohol calorie information on restaurant menus impacted the number of calories ordered from alcoholic beverages or from food and soft drinks. Younger individuals and individuals who exhibit greater motives for good health were more likely to choose to view alcohol calorie labels.

CONCLUSIONS

In two online, hypothetical experiments there is no evidence for alcohol calorie labelling impacting consumer decisions to order alcohol or food. Given the choice, a self-selecting group of individuals who are more motivated by health concerns will view alcohol calorie labels, and in turn may be less likely to order alcohol.

Impact on beer sales of removing the pint serving size: An A-B-A reversal trial in pubs, bars, and restaurants in England

BACKGROUND

Smaller serving sizes could contribute towards reducing alcohol consumption across populations and thereby decrease the risk of 7 cancers and other diseases. To our knowledge, the current study is the first to assess the impact on beer, lager, and cider sales (hereafter, for ease, referred to just as "beer sales") of removing the largest draught serving size (1 imperial pint) from the options available in licensed premises under real-word conditions.

METHODS AND FINDINGS

The study was conducted between February and May 2023, in 13 licensed premises in England. It used an A-B-A reversal design, set over 3 consecutive 4-weekly periods with "A" representing the nonintervention periods during which standard serving sizes were served, and "B" representing the intervention period when the largest serving size of draught beer (1 imperial pint (568 ml)) was removed from existing ranges so that the largest size available was two-thirds of a pint. Where two-third pints were not served, the intervention included introducing this serving size in conjunction with removing the pint serving size. The primary outcome was the mean daily volume of all beer sold, including draught, bottles, and cans (in ml), extracted from electronic sales data. Secondary outcomes were mean daily volume of wine sold (ml) and daily revenue (£). Thirteen premises completed the study, 12 of which did so per protocol and were included in the primary analysis. After adjusting for prespecified covariates, the intervention resulted in a mean daily change of -2,769 ml (95% CI [-4,188, -1,578] p < 0.001) or -9.7% (95% CI [-13.5%, -6.1%] in beer sold. The daily volume of wine sold increased during the intervention period by 232 ml (95% CI [13, 487], p = 0.035) or 7.2% (95% CI [0.4%, 14.5%]). Daily revenues decreased by 5.0% (95% CI [9.6%, -0.3%], p = 0.038).

CONCLUSIONS

Removing the largest serving size (the imperial pint) for draught beer reduced the volume of beer sold. Given the potential of this intervention to reduce alcohol consumption, it merits consideration in alcohol control policies.

TRIAL REGISTRATION

ISRCTN.com ISRCTN18365249.

Can a health warning label diminish the persuasive effects of health-oriented nutrition advertising on ready-to-drink alcohol product packaging? A randomized experiment

BACKGROUND AND AIMS

A health warning label (HWL) cautioning about the link between alcohol and cancer may be able to communicate alcohol risks to consumers and potentially counter health-oriented nutrition advertising on ready-to-drink alcoholic beverages. This study aimed to examine the independent and combined effects of nutrient content claims (e.g. 0 g sugar) and a HWL on perceived product characteristics and intentions to consume, and whether these effects differed by gender and age.

DESIGN

A between-subjects randomized experiment. Participants were randomized to view one of six experimental label conditions: nutrient content claims plus nutrition declaration (NCC + ND), ND only, NCC + ND + HWL, ND + HWL, HWL only and no NCC, ND or HWL, all on a ready-to-drink (RTD) vodka-based soda container.

SETTING AND PARTICIPANTS

Alcohol consumers (n = 5063; 52% women) in Canada aged 18-64 recruited through a national online panel.

MEASUREMENTS

Participants completed ratings of perceived product characteristics, perceived product health risks, and intentions to try, buy, binge and drink the product.

FINDINGS

Compared with the reference condition NCC + ND (current policy scenario in Canada), the other five experimental label conditions were associated with lower ratings for perceiving the product as healthy. All experimental conditions with a HWL were associated with lower product appeal, higher risk perceptions and reduced intentions to try, buy and binge. The experimental condition with a HWL only was associated with intentions to consume fewer cans in the next 7 days (β = -0.72, 95% confidence interval [CI] = -1.37,-0.08) versus the reference. Few interactions were observed, suggesting that label effects on outcomes were similar by gender and age.

CONCLUSIONS

Health warning labels on alcohol packaging appear to be associated with lower product appeal, higher perceived health risks and reduced consumption intentions, even in the presence of nutrient content claims.

The effects of alcohol container labels on consumption behaviour, knowledge, and support for labelling: a systematic review

Alcohol container labels might reduce population-level alcohol-related harms, but investigations of their effectiveness have varied in approach and quality. A systematic synthesis is needed to adjust for these differences and to yield evidence to inform policy. Our objectives were to establish the effects of alcohol container labels bearing one or more health warnings, standard drink information, or low-risk drinking guidance on alcohol consumption behaviour, knowledge of label message, and support for labels. We completed a systematic review according to Cochrane and synthesis without meta-analysis standards. We included all peer-reviewed studies and grey literature published from Jan 1, 1989, to March 6, 2024, in English, French, German, or Spanish that investigated the effects of alcohol container labels compared with no-label or existing label control groups in any population on alcohol consumption behaviour, knowledge of label message, or support for labels. Data were synthesised narratively as impact statements and assessed for risk of bias and certainty in the evidence. A protocol was preregistered (PROSPERO CRD42020168240). We identified 40 publications that studied 31 labels and generated 17 impact statements. 24 (60%) of 40 publications focused on consumption behaviour and we had low or very low certainty in 13 (59%) of 22 outcomes. Alcohol container labels bearing health warnings might slow the rate of alcohol consumption (low certainty), reduce alcoholic beverage selection (moderate certainty), reduce consumption during pregnancy (low certainty), and reduce consumption before driving (moderate certainty). Interventions with multiple types of rotating alcohol container labels likely substantially decrease alcohol use (moderate certainty) and reduce alcohol sales (high certainty). To the best of our knowledge, this is the first systematic review on multiple types of alcohol container labels assessing their effects for certainty in the evidence. Limitations included heterogeneity in label designs and outcome measurements. Alcohol container labels probably influence some alcohol consumption behaviour, with multiple rotating messages being particularly effective, although effects might vary depending on individual health literacy or drinking behaviour. Alcohol container labels might therefore be effective components of policies designed to address population-level alcohol-related harms.