Introduction

The rising burden of non-communicable diseases (NCDs) has emerged as an invisible epidemic in low- and middle-income countries (LMICs). Of all of the deaths from NCDs worldwide, nearly three-quarters occur in LMICs, driven by aging populations, unhealthy lifestyles, and increasing consumption of processed and ultraprocessed food products [1]. In Bangladesh, changes in lifestyle, increased purchasing power, and rapid urbanization contributed to a notable shift in dietary preferences toward the consumption of commercially produced packaged foods (hereafter, termed as packaged foods) [2,3].

Recent evidence shows widespread consumption of packaged foods across both rural and urban areas in Bangladesh, with significant variation by age group [4]. The frequency of unhealthy food and beverage consumption among adolescents in Bangladesh is high in both urban and rural areas [5]. The same national survey also reported higher consumption of unhealthy foods and beverages among adults (20–59 y) [6] and elderly people (≥60 y) [7].

Packaged foods are typically high in sugar, sodium, SFAs, and trans fatty acids and are high in energy. Excessive intake of these foods leads to an enhanced risk of overweight and obesity, NCDs, and related mortality [[8], [9], [10]]. In current practices, to protect consumers’ health and safety, food labeling is regulated by the Bangladesh Food Safety Authority, and regulations include nutrition information (total calories, protein, fat, carbohydrates, total sugar, sodium, and salt) per 100 mL or 100 g pack [11]. However, recent evidence indicates that consumers predominantly check the manufacturing or expiry date on packaged foods, while only a small proportion consult the nutrition facts panel, and those who do often face difficulties interpreting the information provided [12]. To help consumers identify unhealthy packaged foods and beverages, front-of-package labels (FOPLs) have been recommended by the WHO [13]. Therefore, introducing FOPLs in Bangladesh is now essential to control the consumption of ultraprocessed foods, overcoming barriers such as illiteracy, low awareness, and distrust.

Existing literature suggests that using a warning label (WL) to inform consumers about unhealthy foods and discourage their consumption is likely to produce the most considerable health benefits. In contrast, there is limited country-specific evidence on the effectiveness of other interpretive FOPLs, such as multiple traffic lights (MTLs), health star ratings (HSRs), and the guideline daily allowance (GDA) [14]. A qualitative study on FOPL was conducted in Bangladesh [15] to assess potential consumers’ reactions to various FOPL formats especially designed for Bangladesh and found that interpretative FOPLs were well understood by consumers, particularly WLs. However, no previous study in Bangladesh has systematically assessed the effect of exposure to various FOPL formats on the ability of consumers to identify foods high in fat, sugar, and sodium (HFSS), a key step on the pathway to reducing consumption. Moreover, experimental studies conducted in other countries such as India [16], South Africa [17], and Kenya [18] did not include adolescents, a population that frequently consumes packaged foods.

The objective of this study was to experimentally test the impact of 4 FOPL formats (WL, HSR, MTL, and GDA) compared with a control label on Bangladeshi adults’ and adolescents’ ability to identify HFSS foods and their intention to purchase these products. In addition, the secondary objective of the study was to study the perceptions of unhealthiness, perceived message effectiveness (PME), and cognitive elaboration. Additional outcomes assessed included participants’ reactions to different FOPL formats.