The portion size effect and overconsumption – towards downsizing solutions for children and adolescents – An update

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.

Food portion sizes: trends and drivers in an obesogenic environment

The prevalence of overweight and obesity in children and adults has increased worldwide. A strong environmental factor contributing to the obesity epidemic is food portion size (PS). This review evaluates the current evidence linking food PS to obesity, examines the effects of PS on energy intake (EI), and discusses the drivers of food PS selection. The leading causes of the rise in PS include globalisation, intensive farming methods, the impact of World War II, due to shortage of staple foods, and the notion of 'waste not, want not'. Large PS of energy-dense foods may stimulate overconsumption, leading to high EI levels. However, the studies have not shown a cause-and-effect relationship, due to confounding factors. Important mechanisms explaining the attractiveness of larger PS leading to higher EI levels are value for money, portion distortion, labels on food packaging, and tableware. Consumers depend on external rather than internal PS cues to guide consumption, irrespective of satiety levels. Further research is recommended on food consumption patterns to inform policymakers and provide information and insights about changes in diet.

An Exploratory Research to Assess Total Nutritional Knowledge of Students at the University of Lahore, Pakistan

Background: Good nutrition is imperative to achieve a better health status. The rate of obesity and related comorbidities is increasing all over the world. The main reasons behind this worse situation are the overconsumption of food groups or exceeding the recommended portion sizes. University life is a period when students are independent in making their food choices. The chances of adopting unhealthy eating behaviors are increased during this tenure. Nutritional knowledge is an important tool in assessing the nutritional status of an individual, group, and community. Objectives: The main objective of the current study was to assess the nutritional knowledge of university-going students. Methods: The pre-tested questionnaire was used to collect the data from the students of the University of Lahore, Pakistan. A total of 300 students participated in this study (150 from the Nutrition Department and 150 from the non-nutrition departments). Demographic data, anthropometric measurements, and total nutritional knowledge (TNK) scores were measured during the 4-month study duration. Additionally, gender-and department-based comparisons of various parameters were performed. The mean TNK of the Nutrition Department students was higher (34.89 ± 0.95/58) than non-nutrition departments (24.05 ± 1.00/58) (P = 0.01). Additionally, the mean TNK of female students was higher (28.53 ± 1.28/58) than male students (27.05 ± 1.27/58) (P = 0.03). Moreover, 61% and 63% of nutrition students were familiar with the relationship between high intake of salt and fats with chronic diseases, respectively. Results: A statistically significant relationship was not observed between gender (P = 0.78) and departments (P = 0.10) with body mass index (BMI). This finding shows that nutritional knowledge alone is not a predictor of the nutritional status (BMI) of an individual. Students, even from the Nutrition Department, failed to transform their knowledge about nutrition into healthy food choices and eating practices. Conclusions: It is necessary to initiate nutrition education programs emphasizing making healthy food choices. Moreover, nutritional knowledge related to dietary guidelines should be incorporated into daily life to remove the disease burden associated with obesity.

How food overconsumption has hijacked our notions about eating as a pleasurable activity

The negative effects of overconsumption of food have been extensively studied, with a focus on overweight and negative food attitudes. In this overview, we argue that this negative perspective has spilled over to food consumption in general, which is in contrast with eating as a pleasurable activity that contributes to people's well-being. We review four areas of research that have recently emerged: (de)moralization of food consumption, moderate eating for pleasure, intuitive and mindful eating, and the social benefits of eating. Throughout these four themes, it becomes clear that there needs to be a clear distinction between overconsumption of food, bearing negative consequences, and normal levels of food consumption. The latter is positively associated with enjoyment, contentment, and our social and psychological well-being.

Development of a Simplified Portion Size Selection Task

Portion size is an important determinant of energy intake and the development of easy to use and valid tools for measuring portion size are required. Standard measures, such as ad libitum designs and currently available computerized portion selection tasks (PSTs), have several limitations including only being able to capture responses to a limited number of foods, requiring participants’ physical presence and logistical/technical demands. The objective of the current study was to develop and test robust and valid measures of portion size that can be readily prepared by researchers and be reliably utilized for remote online data collection. We developed and tested two simplified PSTs that could be utilized online: (1) portion size images presented simultaneously along a horizontal continuum slider and (2) multiple-choice images presented vertically. One hundred and fifty participants (M = 21.35 years old) completed both simplified PSTs, a standard computerized PST and a series of questionnaires of variables associated with portion size (e.g., hunger, food item characteristics, Three Factor Eating Questionnaire). We found average liking of foods was a significant predictor of all three tasks and cognitive restraint also predicted the two simplified PSTs. We also found significant agreement between the standard PST and estimated portion sizes derived from the simplified PSTs when accounting for average liking. Overall, we show that simplified versions of the standard PST can be used online as an analogue of estimating ideal portion size.

Integrating nutrition into the mathematics curriculum in Australian primary schools: protocol for a randomised controlled trial

Background

Nutrition education programs in schools have been effective in improving children’s knowledge and behaviours related to food and nutrition. However, teachers find it challenging to implement such programs due to overcrowded curricula. Integrating nutrition with core subjects such as mathematics could potentially address time constraints and improve the learning of both. The primary aim of this randomized controlled trial (RCT) is to evaluate the impact of a cross-curricular nutrition and mathematics program on primary school students’ portion size estimation skills. Secondary aims include impact on their nutrition knowledge, attitudes towards mathematics and evaluating the quality of the lessons.

Methods

Twelve Year 3–4 classes from Catholic schools in New South Wales, Australia will be randomised to intervention (n = 6) or control (n = 6) groups. Teachers in the intervention group will receive a professional development workshop and resources to teach 4–5 lessons on portion size and measurements across 1–4 weeks. Outcome measures include portion size estimation skills, nutrition knowledge and attitudes towards mathematics, with data collected during three school visits (pre-intervention, immediately post-intervention, 4 weeks post-intervention). Additionally, teaching quality will be assessed in both intervention and control groups and process evaluation undertaken using teacher interviews and student focus groups.

Discussion

This RCT uses an innovative approach to improve both nutrition and mathematics related learning outcomes among primary school children. It has the potential to impact teaching practices regarding integration of nutrition into curricula and enhance the implementation of nutrition education interventions.

Trial registration

Australian and New Zealand Clinical Trials Register ACTRN12619001071112 31/07/2019.