Perceived Healthfulness, Nutrient Content Awareness, Consumption, and Intention to Purchase Selected Ultraprocessed Products Among Adults in South Africa
Abstract
Objective: To investigate the perceived healthfulness, nutrient content awareness, consumption, and intention to purchase selected ultraprocessed products (UPP) and their sociodemographic determinants.
Design: Cross-sectional study involving secondary data analysis.
Setting: This study was conducted in all nine provinces of South Africa.
Participants: In total, 1951 adults (18–50 years), with 63.5% females and 66.3% from low socioeconomic group.
Methods: Participants were shown A4 images of mock-branded UPP, with no nutrition information provided. Questions asked were based on the images to determine the nutrient content awareness, healthfulness perception, consumption frequency, and intention to purchase the UPP based on sociodemographic characteristics.
Analysis: Descriptive statistics were conducted for nutrient content awareness, perceived healthfulness, consumption, and intention to purchase UPP. Associations with sociodemographic variables were determined using regression analyses: logistic regression for perceived healthfulness and nutrient content awareness, ordinary least square regression for UPP consumption, and intention to purchase was modeled as a latent variable in a multiple indicators multiple cause (MIMIC) model.
Results: Over a third of participants (41.8%) were not aware that fruit juice is high in sugar. Only 13% of the participants perceived fruit juice as unhealthy and more than 50% showed the intention to purchase fruit juice, cereals, and yoghurt in the future. More than 50% reported consuming most UPP either daily or weekly. Perceived healthfulness was associated with gender, while UPP consumption was associated with education, age, gender, and being unemployed. Intention to purchase UPP was the only variable associated with socioeconomic status.
Conclusion and Implications: Intervention strategies such as simplified front-of-pack labeling may have a role in improving nutrition awareness and discouraging UPP consumption.
1. Introduction
Exposure to ultraprocessed products (UPP) continue to increase in low- and middle-income countries, including South Africa [1, 2]. UPP are defined as industrially formulated, ready-to-consume and ready-to-heat products, made by combining several substances derived from foods [3, 4]. These products are associated with noncommunicable diseases (NCDs) due to their unhealthy nutrient profile [4], addictive nature [5], and are associated with poor dietary quality [6]. Most are high in sugar, saturated fats and salt, and are low in essential nutrients and phytochemicals that protect against NCDs. There is consensus that high UPP consumption results in increased energy intake and increases the risks for obesity and NCDs [7, 8].
Based on the nature, purpose, and extent of processing, the NOVA classification categorizes food into four groups, namely the unprocessed or minimally processed (Group 1), processed culinary ingredients (Group 2), processed (Group 3), and UPP (Group 4) [3, 9]. Minimally processed or unprocessed foods are consumed in their natural state or undergo very little processing. These include fresh, squeezed, dried, frozen, canned fruits and vegetables, fresh or pasteurized fruit juice without any added sugar, sweeteners, additives, legumes, eggs, oats, plain yoghurt without any added sugar or artificial sweeteners, etc. [10]. Processed culinary ingredients include ingredients such as salt, sugar, and vegetable oils which are usually used in the kitchen to enhance the taste and flavor of foods from other groups, for example, group 1 foods [11]. Processed foods, on the other hand, include a combination of groups 1 and 2 foods and these include cheese, bread, canned fruit and vegetables, etc. These products may contain additives and usually contain around three ingredients [10, 12]. UPP typically contains five or more ingredients, stabilizers, ingredients such as casein, corn syrup that are not typically used at the household level and may contain very little amounts of group 1 foods. Examples of UPP are carbonated drinks, sweetened yoghurts, sweet and savory snacks, margarine and spreads, sweetened breakfast cereals, sweetened fruit juices, etc. [3, 10].
An analysis of sales demonstrated a leap in UPP sales in South Africa between the period 2005 and 2010 [13] and according to Frank et al. [14], in 2018, almost 80% of all packaged products in the South African supermarkets were ultraprocessed. An analysis of the Euromonitor data in South Africa similarly reported increased consumption of UPP between the years 2005 and 2019 [2]. According to the report, breakfast cereals consumption increased by about 50%, carbonated drinks (sweetened nonalcoholic drinks that contain carbon dioxide) by 82%, and sweet and savory snacks by 100% in that period [2]. The increase in UPP consumption occurs at the same time that the obesity rates [15] and morbidity and mortality from NCDs are increasing [16]. In 2016, NCDs accounted for 51% of deaths in South Africa [17], a prevalence rate that quickly rose to 57.4% a year later [18]. High UPP consumption has thus become a public health concern and this study aims to profile its determinants to inform policy interventions geared toward improving the dietary quality and health status of the population.
Purchasing of UPP is influenced by various factors including price [19], taste [20], health consciousness, and perceived healthfulness [21]. Mai and Hoffman [22] define perceived healthfulness as consumers’ expectation of products influence on the state of health. Although unhealthy foods are at times purchased for enjoyment [23], according to Plasek, Lakner, and Temesi [24], the more healthful a product is considered to be, the higher the likelihood that it will be purchased. Accurate perception of products nutritional quality is therefore important in fostering healthy dietary patterns. Consumers are often not aware of the unhealthiness of some UPP [25] as these products are often portrayed as healthy through nutrition/health claims and natural imagery on the front of product packages [10]. This creates a perception of healthfulness in consumers’ minds [10, 26] as consumers often associate certain food categories [27] or nutrition claims [28] with healthfulness.
Previous studies suggest that perceived healthfulness may be product category dependent and misinterpreted. For example, Machiels and Karnal [29] reported increased healthfulness perception for fruit juice due to whole fruit displayed on a fruit juice packaging. In a previous study in South Africa, consumers also perceived 100% fruit juice as healthy and believed it possesses disease prevention properties [25]. Similarly, breakfast cereal is also often associated with greater healthfulness perception due to its association with wholegrains and perceived higher fiber content [29]. Consumption of these foods is increasing in South Africa; however, little is known regarding South African consumers’ perception of these UPP.
Perceived healthfulness and UPP consumption are said to differ according to sociodemographic status. Investigation into these determinants would help identify population groups for targeted interventions. Though not always the case [26], some studies have previously reported an association between sociodemographic factors and perceived product healthfulness [30, 31]. Prada et al. [26], however, reported no associations probably due to the reason that the majority of participants in the latter study were female, young, and had attained higher educational status. Previous studies also indicate that nutrition awareness is higher among females, the younger group [31] and individuals with higher educational attainment [32]. Additionally, a previous study found that low-income participants perceived most UPP as healthful compared to middle- and high-income groups [33]. In the same vein, other studies reported associations between low-income groups and higher consumption of UPP [34, 35], although the results are not always consistent.
South Africa is a middle-income country that experiences both high economic growth and food insecurity simultaneously [36, 37]. Due to high food costs, consumers often rely on UPP that are cheaper and more filling, despite their inferior nutritional composition [38]. In addition, due to urbanization experienced in the country, fewer people produce their own food and rely more on supermarkets that sell more UPP as opposed to healthy food [14, 36]. Studies that determine the extent and determinants of UPP are therefore important in curbing the increasing consumption rates in the country. The current study is particularly important due to the high unemployment rates leading to a large proportion of the South African population living below poverty line and therefore leaning more toward UPP [37, 39].
According to the theoretical framework by Fogg [40], one of the strategies to reduce consumption of UPP is through changing consumers perceptions toward them. Although studies [2, 38] indicate high UPP consumption, little is however known about nutrient content awareness and how South Africans perceive these UPP. This study seeks to close this gap by documenting South African consumers perception toward UPP, their consumption, and future intention to purchase UPP. Additionally, this study reports on the associated sociodemographic determinants. The findings of this study have important implications for strategies aimed at improving nutrient content understanding of foods and may contribute to the prevention of obesity and NCDs.
2. Materials and Methods
2.1. Participants
This cross-sectional study involved analysis of secondary data from a larger project that aimed to develop a front-of-pack food label (FOPL) for South Africa. The study targeted 2500 individuals, with an eventual participation of 1951 adult males and females aged 18–50 years. A sample size was calculated a priori at a power of 90%, 95% confidence level, and an effect size of 0.136 [41], yielding a sample size of 1526. The sample was increased to 2500 to allow for possible nonresponses.
The sample was selected using stratified multistage random sampling technique. The enumerator areas (EAs) were proportionally stratified in the following order, (1) all nine provinces within the country, (2) in each province, the areas were classified into different geographic locations (metro urban or nonmetro urban or rural), (3) within each geographic location, the EAs were divided according to the different socioeconomic statuses (low, middle, or upper income as determined by the neighborhood lifestyle index [NLI]) [42], and (4) lastly by racial groups (African, Colored, or Mixed-race group, White or Indian).
The metro urban areas are the big and developed towns and cities with high population sizes and are housed within the following eight metropolitan municipalities, namely, Buffalo City, Cape Town, Nelson Mandela Bay, Ethekwini, Tshwane, Johannesburg, Ekurhuleni, and Mangaung [43]. All the other large towns and cities that do not meet the criteria for a metropolitan city are referred to as nonmetro urban areas. The NLI is a system modeled from population dwelling unit information that classifies neighborhoods according to their income and lifestyle characteristics, ranging from 1 (lowest income/poorest community) to 10 (highest income/most affluent community). For this survey, NLI was categorized into three wealth status groups (low, middle, and upper income). The study included individuals who were mainly or partially responsible for purchasing or preparing food and had children below the age of 18 staying within the households. The exclusion criteria were individuals who were employed by the food industry. Data were collected within the households.
A research agency was contracted to recruit the study participants and to collect data. The research agency trained the fieldworkers before the study commencement and data collection took place between November 2019 and January 2020. The fieldworkers approached the selected households to identify eligible participants and to administer the questionnaires. All the fieldworkers had tablets where they captured participants’ responses.
2.2. Study Procedures
Mock-branded images of products considered to be unhealthy [44] and products whose unhealthiness is often misjudged as healthy in South Africa [25, 45] were designed for the purpose of this study. Unhealhiness in this context referred to products that contained high amounts of sugar, salt, and/or fats as defined by the nutrient profile model proposed for South Africa [14]. The product categories included potato chips, soda, fruit juice, sweet biscuits, cereal, and flavored yoghurt (Figure 1). These products were selected based on the products that generated the highest sales in South Africa, according to the 2018 Euromonitor. The products included two sets of UPP—single and product pairs. Single products included a packet of potato chips, fruit juice, and a soda and product pairs included two packets of sweet biscuits, cereal, and flavored yoghurt (Figure 1). The design of the product packages mimicked the actual products found within the stores in South Africa. For example, the cereal container was rectangular, colorful, with images of cereals and the actual word “cereal” written on the front of the package.
All participants were shown mock-branded images of UPP, one at a time, and asked to provide their assessments of the healthfulness and intention to purchase the products. Single products were shown, one at a time and each pair (e.g., two different types of biscuits) was shown simultaneously for the participants to make a comparison and then followed by another set of products (Figure 1). The field workers first presented an image of potato chips, followed by fruit juice, soda, a pair of sweet biscuits, a pair of breakfast cereals, and lastly a pair of flavored yoghurt.
No nutritional information appeared on product packaging. The participants had to determine the level of healthiness based on the information presented on the front of the package. Participants were not informed that the products were ultraprocessed. They had to deduce their own perception of product healthiness. For frequency of consumption, instead of images being presented, participants were asked to state how frequently they consumed the listed products. All data were captured on smartphones.
2.3. Variables Measured
2.3.1. Perceived Healthfulness
In this study, perceived healthfulness was defined as participant’s ability to correctly identify unhealthy products. Only single products (chips, juice, and soda) were used to test for perceived healthfulness. Paired products were excluded as nutrition information was not provided to enable consumers to compare the healthier version of the two products. All three products were ultraprocessed. UPP were defined as industrially formulated, ready-to-consume and ready-to-heat products, made by combining several substances derived from foods [3, 4]. Participants were shown the three single products and the following question was asked: “Do you think this product is unhealthy or healthy?” with the two response options “it is unhealthy or “it is healthy.”
2.4. Nutrient Content Awareness
Participants were further required to identify products containing excess amounts of nutrients of concern, with response options yes/no/unsure. The questions were also based on the three single products (chips, juice, and soda). The following questions were asked for all three products, in this order: (1) “In your opinion does this product contain sugar at levels higher than recommended for a healthy diet?” (2) “In your opinion does this product contain salt at levels higher than recommended for a healthy diet?” and (3) “In your opinion does this product contain saturated fat at levels higher than recommended for a healthy diet?” The participants were to state whether products contained excess amounts of salt, sugar, and/or saturated fats.
2.5. Intention to Purchase UPP
The intention to purchase the UPP was determined from the following question: “How likely are you to purchase this product for yourself or your family” and the responses were ranked on a four-point Likert scale ranging from: “I would definitely not buy it,” “I am unlikely to buy it,” “I will consider buying it,” and “I will definitely buy it.” Questions were based on both single (chips, juice, and soda) and paired products (sweet biscuits, cereal, and flavored yoghurt).
2.6. Consumption of UPP
To determine UPP consumption, participants were asked, on a four-point Likert scale to indicate the frequency of consumption of selected products. The products included potato chips, regular or diet soda, fruit juice, sweet biscuits, sweet breakfast cereals, and flavored yoghurt. The response options included never, monthly, weekly, or daily.
2.7. Sociodemographic Data
The following sociodemographic variables were obtained: age; gender (male/female); educational level (primary [<Grade 7], secondary [Grades 7–11] Grade 12, or tertiary education); urban residency (yes/no); employment status (employed [if receiving any form of income] or unemployed) and metropolitan residency (yes/no). Other variables included the presence of children below 18 years of age within the household (yes/no), whether they were grocery buyers or not (no/yes/share responsibility) and socioeconomic status. Socioeconomic status was categorized as residing in a low- (poorest), middle-, or high-income (most affluent community) area.
2.8. Statistical Analysis
To describe healthfulness perception, nutrient content awareness, intention to purchase and consumption frequency, proportions of the different answers (e.g., yes–no or Likert scale options), and their 95% confidence interval were calculated per food item.
Logistic regression was conducted to assess the association between the subjects’ responses to the perceived healthfulness and nutrient content awareness questions (included as the dependent variable) and sociodemographic factors (included as independent variables). For each of the single products (i.e., chips, juice, and soda), a separate model was built, resulting in three models for perceived healthfulness and four models for nutrient content awareness (i.e., chips high in salt, chips high in fat, juice high in sugar, and soda high in sugar). To study the association between consumption (included as the dependent variable) and sociodemographic factors (included as independent variables), ordinary least squares were used. Likert scale responses for each of the products were transformed to binary variables with “never,” “monthly,” or “weekly use” set equal to 0 and “daily use” set equal to 1). The resulting scores were summed together to a composite score reflecting consumption. While this transformation made the most sense conceptually, sensitivity analysis was conducted using the sum of the nontransformed Likert scales. Intention to purchase was modeled as a latent variable in a multiple indicators multiple causes (MIMICs) model with the same sociodemographic factors included as independent variables. This latent variable was inferred through modeling the variables that measured subjects’ intention to purchase each of the six products using Likert scale responses. The levels of significance were set p-value < “ ∗∗∗” 0.001, “ ∗∗” 0.01 and “ ∗” 0.05.
Considering the sampling strategy, stratification for geographical area, socioeconomic status (SES) and province, clustering at the level of the EAs, and survey design weights were taken into account in the descriptive and regression analyses. R software (R package survey version 4.0) was used for data analysis [46].
3. Results
The study population contained a higher proportion of women (63.5%), middle-aged (27.2%), and most (66.3%) belonged to the lowest of the three socioeconomic status categories (Table 1). The highest proportion of participants had Grade 12 qualification (37.6%), followed by Grades 7–11 (29.3%) and the number employed (50.9%) was more or less equal (49.1%) to those who were unemployment.
| Variables | Response Option | n (%) |
|---|---|---|
| Gender | Female | 1238 (63.5%) |
| Male | 713 (36.5%) | |
| Age category | 18–24 | 368 (18.9%) |
| 25–29 | 339 (17.4%) | |
| 30–39 | 531 (27.2%) | |
| 40–49 | 342 (17.5%) | |
| 50–59 | 200 (10.3%) | |
| 60+ | 169 (8.7%) | |
| Educational level | <Grade 7 | 155 (7.9%) |
| Grade 7–11 | 571 (29.3%) | |
| ≥Grade 12 | 734 (37.6%) | |
| Tertiary | 491 (25.2%) | |
| Socioeconomic statusa | Low | 1293 (66.3%) |
| Middle | 547 (28.0%) | |
| Employment | High | 111 (5.7%) |
| Yes | 993 (50.9%) | |
| Married or living together | No | 1194 (61.2%) |
| Yes | 757 (38.8%) | |
| Place of residence | Metro, urbanb | 1133 (58.1%) |
| Nonmetro, urban | 645 (33.1%) | |
| Nonmetro, rural | 173 (8.9%) | |
| Influence on food purchase | No, I am not the main buyer | 150 (7.7%) |
| Yes, I am the main buyer | 1112 (57.0%) | |
| No, but I do share the responsibility | 689 (35.3%) | |
| Children in household | No | 430 (22.0%) |
| Yes | 1521 (78.0%) | |
- aSocioeconomic status was defined as residing in a low-, middle-, or high-income area.
- bMetro urban = 8 specific large cities and towns in the country, urban areas = other cities and towns that do not meet the metropolitan criteria.
A higher proportion resided in a metropolitan urban area (58.1%) and most participants were the ones mainly responsible for buying groceries (57%) or at least they shared this responsibility (35.3%).
3.1. Healthfulness Perception and Nutrient Content Awareness
Most participants (82.8% and 79.6%) correctly perceived chips and soda as unhealthy, respectively. Only a few participants (13%) knew that fruit juice was unhealthy (Table 2).
| Food item | Healthy | Unhealthy |
|---|---|---|
| Percentage (95% CI) | Percentage (95% CI) | |
| Potato chips | 17.2 (13.2–21.2) | 82.8 (78.8–86.8) |
| Fruit juice | 87.0 (84.8–89.3) | 13 (10.7–15.2) |
| Soda | 20.4 (17.7–23.1) | 79.6 (76.9–82.3) |
- Note: Responses based on images presented to participants. Estimates and standard errors were adjusted for clustering at the level of the enumerator area, survey design weights, and stratification of geographical area and demographic groups.
- Abbreviation: 95% CI, 95% confidence interval.
Regarding nutrient content awareness, more than half (58.1%) were not aware that chips are high in fat, and over a third (41.8%) were not aware that fruit juice is high in sugar (Table 3).
| Item | Yes (%) (95% CI) | No (%) (95% CI) | Unsure (%) (95% CI) |
|---|---|---|---|
| Chips high in salt | 64.1 (60.8–67.4) | 27.2 (24.0–30.3) | 8.7 (7.0–10.4) |
| Chips high in fat | 41.8 (38.3–45.3) | 39.4 (36.3–42.5) | 18.7 (15.4–21.9) |
| Fruit juice high in sugar | 58.2 (54.4–61.9) | 35.1 (31.7–38.6) | 6.7 (5.4–7.9) |
| Soda high in sugar | 72.1 (68.5–75.6) | 18.3 (15.2–21.5) | 9.6 (7.8–11.4) |
- Note: Estimates and standard errors were adjusted for clustering at the level of the enumerator area, survey design weights, and stratification of geographical area and demographic groups.
- Abbreviation: 95% CI, 95% confidence interval.
3.2. Intention to Purchase Selected UPPs
More than 50% of the participants reported high intention to purchase fruit juice (59%), cereal (50.3%), and flavored yoghurt (52.5%) (Table 4). Soda was the least likely (32.4%) product to be purchased.
| Food item | Intention to purchase | Percentage (%) | 95% Confidence interval |
|---|---|---|---|
| Potato chips | Definitely yes | 45.1 | (40.8–49.4) |
| Fruit juice | Definitely yes | 59 | (55.8–62.2) |
| Soda | Definitely yes | 32.4 | (29.7–35) |
| Sweet biscuits | Definitely yes | 47.1 | (42.8–51.4) |
| Breakfast cereal | Definitely yes | 50.3 | (46.7–54) |
| Flavored yoghurt | Definitely yes | 52.5 | (49.5–55.6) |
- Note: 95% confidence interval. Estimates and standard errors were adjusted for clustering at the level of the enumerator area, survey design weights, and stratification of geographical area and demographic groups.
3.3. Self-Reported Consumption of UPP
Self-reported consumption of UPP was high. For each category, consumption on at least a weekly basis exceeded 50%, except for chips (46.7%) and soda (37.9%) (Table 5). For each category, at least 10% of participants reported to consume UPP on a daily basis, except for soda consumption (i.e., 9.5%).
| Food type | Frequency | Percentage | 95% CI |
|---|---|---|---|
| Potato chips |
|
|
|
| Regular or diet soda |
|
|
|
| Fruit juice |
|
|
|
| Sweet biscuits |
|
|
|
| Breakfast cereal |
|
|
|
| Flavored yoghurt |
|
|
|
- Note: 95% confidence interval. Estimates and standard errors were adjusted for clustering at the level of the enumerator area, survey design weights, and stratification of geographical area and demographic groups.
3.4. Associations With Sociodemographic and Socioeconomic Status
There was no association between SES and perceived healthfulness or nutrient content awareness for any product (p > 0.05). Nutrient content awareness and perceived healthfulness (Tables 6 and 7) did not show any consistent associations across products except for males judging selected UPF to be unhealthy less often than females (Table 7).
| Predictor | Chips (SE) |
Juice (SE) |
Soda (SE) |
|---|---|---|---|
| Age 24–29 yearsa |
|
|
|
| Age 30–39 yearsa |
|
|
|
| Age 40–49 yearsa |
|
|
|
| Age 50–59 yearsa |
|
|
|
| Age 60+ yearsa |
|
|
|
| Education: 7–11 yearsb |
|
|
|
| Education: 12–13 yearsb |
|
|
|
| Education: tertiaryb |
|
|
|
| Gender: male |
|
|
|
| Metropolitan resident |
|
|
|
| Urban resident |
|
|
|
| Main buyerc |
|
|
|
| Shared responsibilityc |
|
|
|
| Children in household |
|
|
|
| Married or living together |
|
|
|
| Currently employed |
|
|
|
| SES-category middled |
|
|
|
| SES-category upperd |
|
|
|
- Note: Logistic regression estimates for awareness of unhealthiness adjusted for clustering at the level of the enumerator area, survey design weights, and stratification of geographical area and demographic groups.
- Abbreviation: SE, standard error.
- aAge 18–23 years.
- bEducation: <6 years.
- cNot the main buyer.
- dSES-, category lower.
- Significance codes: “ ∗” 0.05, “ ∗∗” 0.01, “ ∗∗∗” 0.001.
| Predictor | Chips salt (SE) | Chips fat (SE) | Juice sugar (SE) | Soda sugar (SE) |
|---|---|---|---|---|
| Age 24–29 yearsa |
|
|
|
|
| Age 30–39 yearsa |
|
|
|
|
| Age 40–49 yearsa |
|
|
|
|
| Age 50–59 yearsa |
|
|
|
|
| Age 60+ yearsa |
|
|
|
|
| Education: 7–11 yearsb |
|
|
|
|
| Education: 12–13 yearsb |
|
|
|
|
| Education: tertiaryb |
|
|
|
|
| Gender: male |
|
|
|
|
| Metropolitan resident |
|
|
|
|
| Urban resident |
|
|
|
|
| Main buyerc |
|
|
|
|
| Shared responsibilityc |
|
|
|
|
| Children in household |
|
|
|
|
| Married or living together |
|
|
|
|
| Currently employed |
|
|
|
|
| SES-category middled |
|
|
|
|
| SES-category upperd |
|
|
|
|
- Note: Logistic regression estimates for awareness of nutrients of concern adjusted for clustering at the level of the enumerator area, survey design weights, and stratification of geographical area and demographic groups.
- Abbreviation: SE, standard error.
- aAge 18–23 years.
- bEducation: <6 years.
- cNot the main buyer.
- dSES-, category lower.
- Significance codes: “ ∗” 0.05, “ ∗∗” 0.01, “ ∗∗∗” 0.001.
Low or middle SES, having children in the household and not residing in a metropolitan area were associated with a higher intention to purchase UPP (Table 8) (p < 0.05). Intention to purchase UPP was the only variable associated with socioeconomic status. The analysis did not reveal any association with educational status.
| Predictor | Intention to purchase (SE) |
Consumption (SE) |
|---|---|---|
| Age 24–29 yearsa |
|
|
| Age 30–39 yearsa |
|
|
| Age 40–49 yearsa |
|
|
| Age 50–59 yearsa |
|
|
| Age 60+ yearsa |
|
|
| Education: 7–11 yearsb |
|
|
| Education: 12–13 yearsb |
|
|
| Education: tertiaryb |
|
|
| Gender: male |
|
|
| Metropolitan resident |
|
|
| Urban resident |
|
|
| Main buyerc |
|
|
| Children in householdd |
|
|
| Married or living together |
|
|
| Currently employed |
|
|
| SES-category middlee |
|
|
| SES-category uppere |
|
|
- Note: Ordinary least square regression estimates for intention to purchase and consumption of ultraprocessed foods adjusted for clustering at the level of the enumerator area, survey design weights, and stratification of geographical area and demographic groups.
- Abbreviation: SE, standard error.
- aAge 18–23 years.
- bEducation: <6 years.
- cNot the main buyer.
- dNo children in household.
- eSES-category lower.
- Significance codes: “ ∗” 0.05, “ ∗∗” 0.01, “ ∗∗∗” 0.001.
We considered the association between sociodemographic determinants and the number of UPP reportedly being consumed on a weekly or daily basis (Table 8). Lower educational status, male, older age (50–59 years), not being employed and not living with children below 18 years of age were associated with higher consumption of the selected UPP (p < 0.05).
4. Discussion
The objective of this study was to describe the perceived healthfulness, nutrient content awareness, consumption, and intention to purchase selected UPP. The study also investigated the sociodemographic determinants of UPP. Most participants perceived fruit juice as healthy and a considerable number of participants were not aware that fruit juice is high in sugar. Although UPP consumption differed by product category, more than half of the participants reported consuming UPP either daily or on a weekly basis for most products.
The associations across products and across the envisaged outcomes of awareness, intention to purchase and UPP consumption showed to be inconsistent. For example, people of older age were more aware of chips and juice being unhealthy while an opposite trend seemed to hold for soda (although not fully significant). Perceived healthfulness was however associated with gender: females were more likely to perceive UPP as unhealthy. Higher UPP consumption was associated with education, age, and gender. The intention to purchase UPP was higher among the low and middle SES group compared to high SES.
Overall, consumption of the selected UPP was high in the current study. This is in line with other local studies that showed high consumption of UPP [38] such as sugar-sweetened beverages, sweet biscuits and salty snacks, instant noodles, and sugar-sweetened breakfast cereals [2]. The high UPP consumption could be explained by the mushrooming of shops and supermarkets mainly offering and therefore increasing the accessibility of UPP [47], especially in more impoverished areas [47]. UPP may be more appealing as they are convenient, tastier, and more affordable and their consumption may be fueled by marketing from manufacturers [48]. Consumption needs to be curbed to prevent further increases in obesity rates and obesity-related NCDs.
A high proportion of participants correctly perceived soda and chips as unhealthy whilst a very low proportion correctly perceived fruit juice as unhealthy. Only about half of the participants in the current study were aware that fruit juice is high in sugar, which could have explained the misperception about fruit juice healthiness. Similarly, previous studies in more developed countries reported that participants perceived soda as unhealthy and fruit juice on the other hand as healthy [49, 50]. There is scarcity of data related to perception of healthiness of fruit juice in lower- to middle-income countries, which would be interesting to compare. Fruit juice contains vitamins and minerals and is believed to contain natural sugar [25] and this could have influenced its healthfulness perception in this study. Packaged fruit juice is often marketed as a healthier alternative to soda, despite its high sugar content, which may have also contributed to the misperception of its healthiness. It is also interesting to note that while participants were aware that chips are high in salt, a considerable number were not aware of its fat content. Potato chips are often portrayed as high in salt and the message about its fat content may be overlooked during nutrition education, which may explain the findings of this study. There is therefore a need to create more awareness about the chips nutrient content as a strategy to prevent obesity and NCDs.
The perception of soda as unhealthy by most participants in this study may have been affected by the implementation of the Health Promotion Levy in South Africa [51, 52]. Murukutla et al. [44] in their evaluation of knowledge and attitudes of South African consumers toward SSB tax reported a statistically significant increase (13% vs. 29%) from pre- to post-campaign recall of messages about the harms of sugary drinks. According to Thow, Downs, and Jan [53] application of tax on unhealthy food may raise public awareness as consumers learn that a product is unhealthy because it is being taxed. Other population-wide measures such as taxes and FOPL [54] could be applied to other UPP such as fruit juice to better inform the public. Although influenced by other environmental factors, nutrition knowledge is one of the important steps toward behavior modification and better dietary quality [55].
More than half of the participants in the current study reported that they intended to purchase yoghurt, cereal, and fruit juice in future. The authors speculate that the intention to purchase these products could have been driven by their perceived healthfulness as reported in other studies [25] and as generally portrayed in the media. Among the three products (yoghurt, cereal, and fruit juice), the healthfulness perception was only tested for fruit juice in the current study and it would be interesting to find out what the perception of South African consumers is toward the other two products. Since this was a secondary study, the authors could not analyze the healthfulness perception of yoghurt and cereal (as paired products) due to the way questions were posed in the original study.
The perception of products’ unhealthiness was higher among females which is in line with other studies [30, 31]. Literature indicates that females have better nutrition knowledge [31, 55] which may explain the gender differences in healthfulness perception. The lack of association between SES and UPP consumption was unexpected and is in contrast with findings from other studies that reported high UPP consumption in disadvantaged communities [33, 34], mainly due to food insecurity as is the case for South Africa. A possible explanation for this lack of association is that SES in this study was based on the income level of the EA in which the household was located. As a result, all households from the same EA were considered as having the same SES, even though there may have been differences. The clustering has likely reduced the power of our study. Findings could also have been influenced by the selection of products and the smaller proportion of participants in the high SES category. Future studies should consider a different approximation of SES, including a broader range of products. The lack of association for SES and UPP consumption in this study may imply that these social determinants of health may play a lesser role within the South African context. These findings however need to be investigated further as they differ with findings from different contexts and could change as the situation in South Africa evolves.
Consistent with other studies, we found that lower educational status (less than 7 years of schooling) was associated with higher UPP consumption [32, 56]. Additionally, consistent with other studies, the current study found that more men than women reportedly consumed UPP [56, 57]. Females are reported to be more aware of nutrition information due to higher exposure to food- and health-related information [58].
Being above 60 years of age was positively associated with increased UPP consumption in the current study, contrary to findings by other authors who reported lower UPP among older people [56, 59]. According to Marchese et al. [57], it is not uncommon for older adults to indulge in unhealthy dietary behaviors. In the latter study, the authors reported that although the younger participants had the highest UPP consumption, participants over the age of 71 years had a higher UPP intake compared to the 50–70-year-olds. While consumption in the younger generation is influenced by marketing, higher consumption of unhealthy foods in the older generation may be due to a sense of letting go at times and eating for enjoyment [23]. The reason for the higher consumption of UPP in the older generation in the South African context is not clear. More studies, including qualitative studies, could be conducted to provide more insight.
An important strength was that our study was based on a probability sample, randomly collected from the general population of South Africa. Data were also collected in person which made it possible to reach low socioeconomic segments of the population that may not have online access. The selection of images was based on products that are commonly sold in South Africa and therefore relevant to the context of this study, which is a strength of this study.
SES was measured by a proxy consisting of a combination of income and residential characteristics. This minimized reporting bias compared to variables based on self-reported information. However, using dwelling unit information likely ignored individual variation resulting in lower precision. Hence, we may have lacked power to show an existing association. Future studies could analyze SES at household than at EA level to reflect individuals’ differences. The other limitation in performance could have been limited by the few items assessed and that the healthiness of soda and chips is not very subtle. However, the items were meant to cover both obviously unhealthy products that are usually perceived as unhealthy and those which are often thought of as healthy in South Africa and these findings provide important insight data for policymakers. Self-reported measures and not actual consumption were utilized and we make recommendations that future research considers more objective measures. No nutritional information was presented on the packaging which may have potentially limited the ability to correctly assess products’ healthfulness for some participants. The information was however omitted as previous studies indicate its ineffectiveness in informing consumers on the product’s nutritional composition due to its complexity. Since only a limited number of products were used, future studies could expand on a wider range of food products. It would also be interesting to find out how yoghurt and breakfast cereals are perceived as their consumption is increasing in South Africa. These research gaps could be explored in future studies.
5. Conclusion
Awareness of the unhealthiness and nutrient content of UPP was limited among study participants. It is crucial to address this lack of awareness to decrease to burden of NCDs. Additionally, the consumption of selected UPP was high among South African adults. SES did not seem to be an important determinant of perceived healthfulness, nutrient awareness, or UPP consumption. Associations with sociodemographic factors were not consistent across UPP products and were also not consistent across the studied outcomes of awareness, intention to purchase, and reported consumption. Discrepancies across products are somehow expected since different strata of the population will interact differently toward different types of UPP. As such, our findings support addressing the broader South African population, rather than a specific target group through measures such as implementation of a simplified front-of-package labeling, mass campaigns to sensitize the public about UPP and taxation on UPP. These measures could be leveraged to assist consumers in identifying unhealthy products and changing their consumption behavior.
Conflicts of Interest
The authors declare no conflicts of interest.
Author Contributions
Makoma Bopape and Jeroen De Man shared the first authorship.
Funding
This research was funded by Bloomberg Philanthropies, grant number 5108311.
Acknowledgments
We thank the School of Public Health at the University of the Western Cape and the DSI/NRF CoE in Food Security (UID 91490) for administrative support.
Open Research
Data Availability Statement
The data that support the findings of this study are available from the corresponding author upon reasonable request.
