Impact on wine sales of removing the largest serving size by the glass: An A-B-A reversal trial in 21 pubs, bars, and restaurants in England.

BACKGROUND: Interventions that alter aspects of the physical environments in which unhealthy behaviours occur have the potential to change behaviour at scale, i.e., across populations, and thereby decrease the risk of several diseases. One set of such interventions involves reducing serving sizes, which could reduce alcohol consumption. The effect of modifying the available range of serving sizes of wine in a real-world setting is unknown. We aimed to assess the impact on the volume of wine sold of removing the largest serving size by the glass from the options available in licensed premises. METHODS AND FINDINGS: The study was conducted between September 2021 and May 2022 in 21 licensed premises in England that sold wine by the glass in serving sizes greater than 125 ml (i.e., 175 ml or 250 ml) and used an electronic point of sale till system. It used an A-B-A reversal design, set over 3 four-weekly periods. "A" represented the nonintervention periods during which standard serving sizes were served and "B" the intervention period when the largest serving size for a glass of wine was removed from the existing range in each establishment: 250 ml (18 premises) or 175 ml (3 premises). The primary outcome was the daily volume of wine sold, extracted from sales data. Twenty-one premises completed the study, 20 of which did so per protocol and were included in the primary analysis. After adjusting for prespecified covariates, the intervention resulted in -420·8 millilitres (ml) (95% confidence intervals (CIs) -681·4 to -160·2 p = 0·002) or -7·6% (95% CI -12·3%, -2·9%) less wine being sold per day. There was no evidence that sales of beer and cider or total daily revenues changed but the study was not powered to detect differences in these outcomes. The main study limitation is that we were unable to assess the sales of other alcoholic drinks apart from wine, beer, and cider, estimated to comprise approximately 30% of alcoholic drinks sold in participating premises. CONCLUSIONS: Removing the largest serving size of wine by the glass from those available reduced the volume of wine sold. This promising intervention for decreasing alcohol consumption across populations merits consideration as part of alcohol licensing regulations. TRIAL REGISTRATION: ISRCTN https://doi.org/10.1186/ISRCTN33169631; OSF https://osf.io/xkgdb.

Impact on sales of adding a smaller serving size of beer and cider in licensed premises: an A-B-A reversal design.

BACKGROUND: Smaller serving sizes of alcoholic drinks could reduce alcohol consumption across populations thereby lowering the risk of many diseases. The effect of modifying the available range of serving sizes of beer and cider in a real-world setting has yet to be studied. The current study assessed the impact on beer and cider sales of adding a serving size of draught beer and cider (2/3 pint) that was between the current smallest (1/2 pint) and largest (1 pint) standard serving sizes. METHODS: Twenty-two licensed premises in England consented to taking part in the study. The study used an ABA reversal design, set over three 4-weekly periods, with A representing the non-intervention periods, during which standard serving sizes were served and B the intervention period when a 2/3 pint serving size of draught beer and cider was added to the existing range, along with smaller 1/2 pint and larger 1 pint serving sizes. The primary outcome was the daily volume of beer and cider sold, extracted from sales data. RESULTS: Fourteen premises started the study, of which thirteen completed it. Twelve of those did so per protocol and were included in the primary analysis. After adjusting for pre-specified covariates, the intervention did not have a significant effect on the volume of beer and cider sold per day (3.14 ml; 95%CIs -2.29 to 8.58; p = 0.257). CONCLUSIONS: In licensed premises, there was no evidence that adding a smaller serving size for draught beer and cider (2/3 pint) when the smallest (1/2 pint) and largest (1 pint) sizes were still available, affected the volume of beer and cider sold. Studies are warranted to assess the impact of removing the largest serving size. TRIAL REGISTRATION: ISRCTN: https://doi.org/10.1186/ISRCTN33169631 (08/09/2021), OSF: https://osf.io/xkgdb/ (08/09/2021).

Cigarette pack size and consumption: an adaptive randomised controlled trial.

BACKGROUND: Observational evidence suggests that cigarette pack size - the number of cigarettes in a single pack - is associated with consumption but experimental evidence of a causal relationship is lacking. The tobacco industry is introducing increasingly large packs, in the absence of maximum cigarette pack size regulation. In Australia, the minimum pack size is 20 but packs of up to 50 cigarettes are available. We aimed to estimate the impact on smoking of reducing cigarette pack sizes from ≥25 to 20 cigarettes per pack. METHOD: A two-stage adaptive parallel group RCT in which Australian smokers who usually purchase packs containing ≥25 cigarettes were randomised to use only packs containing either 20 (intervention) or their usual packs (control) for four weeks. The primary outcome, the average number of cigarettes smoked per day, was measured through collecting all finished cigarette packs, labelled with the number of cigarettes participants smoked. An interim sample size re-estimation was used to evaluate the possibility of detecting a meaningful difference in the primary outcome. RESULTS: The interim analysis, conducted when 124 participants had been randomised, suggested 1122 additional participants needed to be randomised for sufficient power to detect a meaningful effect. This exceeded pre-specified criteria for feasible recruitment, and data collection was terminated accordingly. Analysis of complete data (n = 79) indicated that the mean cigarettes smoked per day was 15.9 (SD = 8.5) in the intervention arm and 16.8 (SD = 6.7) among controls (difference - 0.9: 95%CI = - 4.3, 2.6). CONCLUSION: It remains unclear whether reducing cigarette pack sizes from ≥25 to 20 cigarettes reduces cigarette consumption. Importantly, the results of this study provide no evidence that capping cigarette pack sizes would be ineffective at reducing smoking. The limitations identified in this study can inform a more efficient RCT, which is urgently required to address the dearth of experimental evidence on the impact of large cigarette pack sizes on smoking. TRIAL REGISTRATION: https://doi.org/10.1186/ISRCTN34202533.

Plate size and food consumption: a pre-registered experimental study in a general population sample.

BACKGROUND: There is considerable uncertainty regarding the impact of tableware size on food consumption. Most existing studies have used small and unrepresentative samples and have not followed recommended procedures for randomised controlled trials, leading to increased risk of bias. In the first pre-registered study to date, we examined the impact on consumption of using larger versus smaller plates for self-served food. We also assessed impact on the underlying meal micro-structure, such as number of servings and eating rate, which has not previously been studied. METHODS: The setting was a purpose-built naturalistic eating behaviour laboratory. A general population sample of 134 adult participants (aged 18-61 years) was randomly allocated to one of two groups varying in the size of plate used for self-serving lunch: large or small. The primary outcome was amount of food energy (kcal) consumed during a meal. Additionally, we assessed impact on meal micro-structure, and examined potential modifying effects of executive function, socio-economic position, and sensitivity to perceptual cues. RESULTS: There was no clear evidence of a difference in consumption between the two groups: Cohen's d = 0.07 (95% CI [- 0.27, 0.41]), with participants in the large plate group consuming on average 19.2 (95% CI [- 76.5, 115.0]) more calories (3%) compared to the small plate group (large: mean (SD) = 644.1 (265.0) kcal, versus small: 624.9 (292.3) kcal). The difference between the groups was not modified by individual characteristics. There was no evidence of impact on meal micro-structure, with the exception of more food being left on the plate when larger plates were used. CONCLUSIONS: This study suggests that previous meta-analyses of a low-quality body of evidence may have considerably overestimated the effects of plate size on consumption. However, the possibility of a clinically significant effect - in either direction - cannot be excluded. Well-conducted trials of tableware size in real-world field settings are now needed to determine whether changing the size of tableware has potential to contribute to efforts to reduce consumption at population-level. TRIAL REGISTRATION: The study protocol ( https://osf.io/e3dfh/ ) and data analysis plan ( https://osf.io/sh5u7/ ) were pre-registered on the Open Science Framework.

Cigarette pack size and consumption: a randomized cross-over trial.

BACKGROUND AND AIMS: Smoking fewer cigarettes per day may increase the chances of stopping smoking. Capping the number of cigarettes per pack is a promising policy option, but the causal impact of such a change is unknown. This study aimed to test the hypothesis that lowering cigarette pack sizes from 25 to 20 reduces the number of cigarettes smoked. DESIGN: This randomized controlled cross-over trial had two 14-day intervention periods with an intervening 7-day period of usual behaviour. Participants purchased their own cigarettes. They were instructed to smoke their usual brand from either one of two sizes of pack in each of two 14-day intervention periods: (a) 25 cigarettes and (b) 20 cigarettes. Participants were randomized to the order in which they smoked from the two pack sizes (a-b; b-a). SETTING: Canada. PARTICIPANTS: Participants were adult smokers who smoked from pack sizes of 25, recruited between July 2020 and June 2021. Of 252 randomized, 240 (95%) completed the study and 236 (94%) provided sufficient data for the primary analysis. MEASUREMENTS: Cigarettes smoked per participant per day. FINDINGS: Participants smoked fewer cigarettes per day from packs of 20 cigarettes [n = 234, mean = 15.7 standard deviation (SD) = 7.1] than from packs of 25 (n = 235, mean = 16.9, SD = 7.1). After adjusting for pre-specified covariates (baseline consumption and heaviness of smoking), modelling estimated that participants smoked 1.3 fewer cigarettes per day [95% confidence interval (CI) = -1.7 to -0.9], equivalent to 7.6% fewer (95% CI = -10.1 to -5.2%) from packs of 20 cigarettes. CONCLUSIONS: Smoking from packs of 20 compared with 25 cigarettes reduced the number of cigarettes smoked per day.

Should cigarette pack sizes be capped?

BACKGROUND: Very few countries regulate maximum cigarette pack size. Larger, non-standard sizes are increasingly being introduced by the tobacco industry. Larger portion sizes increase food consumption; larger cigarette packs may similarly increase tobacco consumption. Here we consider the evidence for legislation to cap cigarette pack size to reduce tobacco-related harm. AIMS AND ANALYSIS: We first describe the regulations regarding minimum and maximum pack sizes in the 12 countries that have adopted plain packaging legislation and describe the range of sizes available. We then discuss evidence for two key assumptions that would support capping pack size. First, regarding the causal nature of the relationship between pack size and tobacco consumption, observational evidence suggests that people smoke fewer cigarettes when using smaller packs. Secondly, regarding the causal nature of the relationship between reducing consumption and successful cessation, reductions in number of cigarettes smoked per day are associated with increased cessation attempts and subsequent abstinence. However, more experimental evidence is needed to infer the causal nature of these associations among general populations of smokers. CONCLUSION: Cigarette pack size is positively associated with consumption and consumption is negatively associated with cessation. Based on limited evidence of the causal nature of these associations, we hypothesize that government regulations to cap cigarette pack sizes would positively contribute to reducing smoking prevalence.