Soda Consumption Among Adolescents: Implications for Low- and Middle-Income Countries

Sugar-sweetened beverages (SSBs) have no nutritive value, and robust epidemiological evidence from both randomized trials and observational studies has established the harmful effects of SSBs on adiposity, type II diabetes, cardiovascular disease, site-specific cancers, and dental caries.^1–4 Consumption of SSBs, including sodas, energy drinks, and numerous other commercial and homemade beverages with added sugar, is therefore often seen as “low-hanging fruit” to be targeted by public health efforts to stem epidemics of obesity, diabetes, and cardiovascular disease.

Globally, significant burdens of morbidity and mortality from chronic diseases among adults are attributable to SSB intake, with low- and middle-income countries (LMICs), which encompass most of the world’s population, currently carrying the brunt of this burden.⁵ Concurrent with modest declines in SSB consumption in some high-income countries, SSB manufacturers have redirected and redoubled efforts to market SSBs in low- and middle income countries. Previous global analyses assessed SSB intake and associated disease burdens among adults in 187 countries around the world, identifying large heterogeneities in SSB consumption levels in different world regions and highlighting particularly steep age gradients in regions of high consumption, such as Latin America and the Caribbean, with the highest consumption of SSBs in younger adults.⁶

Considering the current evidence on the importance of diet throughout the life course, as well as the well-established effects of marketing and advertising on children, the next logical step in investigating the scope of SSB consumption worldwide is to quantify levels of SSB consumption in children in global populations. In this issue of AJPH, Yang et al. investigate this important issue, using data from a large multicountry survey that measures dietary habits, including SSB consumption, among adolescent populations in LMICs (p. 1095).

GLOBAL SCHOOL-BASED HEALTH SURVEYS

Yang et al. present an analysis of data collected through the Global School-based Health Surveys, an ongoing surveillance effort started in 2003 that is led by the World Health Organization and US Centers for Disease Control and Prevention. The Global School-based Health Surveys collects information on the health behaviors of adolescents aged 12 to 15 years in LMICs around the world. These nationally representative, cross-sectional surveys include a brief questionnaire on dietary habits among adolescents, including since 2009, intake of carbonated soft drinks, which constitute one category of SSBs.

The authors analyzed data from 53 countries reporting soft drink consumption through Global School-based Health Surveys from 2009 to 2013, including 137 449 adolescents with roughly equal proportions of boys and girls aged 12 to 15 years. The countries in this analysis spanned five major world regions: Africa, Central and South America, the Middle East, Southeast Asia, and the Western Pacific.

On the basis of this analysis, soda consumption among adolescents was most frequent in Central and South America, averaging 1.70 times a day, and least frequent in Southeast Asia, where sodas were consumed by adolescents on average 0.85 times each day. Importantly, this analysis indicates that across the entire population of adolescents surveyed in 53 countries, half (54.0%) consumed soft drinks at least once a day. Moreover, roughly one in five adolescents (22.5%) in Central and South America (including the Caribbean) consumed soft drinks three or more times per day.

The countries with the highest consumption levels included Trinidad and Tobago, Kuwait, Algeria, Niue, and Suriname, and those with the lowest consumption included Kiribati, Syria, Malaysia, Benin, and the Maldives, indicating significant heterogeneity within regions other than Central and South America, where frequency of intake was uniformly high across many of the countries surveyed.

PARTIAL PICTURE

The analysis by Yang et al. provides important evidence indicating frequent consumption of sodas among young adolescents in many LMICs and is derived from nationally representative data from 53 countries from all major world regions that were collected using uniform surveillance methods across countries. However, this analysis presents only part of the whole picture of SSB consumption in LMICs because it covers less than half of the approximately 135 countries that the World Bank currently categorizes as low or middle income.

A strength of this investigation is that the data are fairly recent, from 2009 to 2013, but the lack of older data precludes analysis of time trends of soda consumption among youths. Furthermore, by examining only intake of carbonated sodas, which are a single class of SSBs, this analysis may underestimate the true frequency of all SSB consumption in adolescents, particularly in countries where homemade SSBs, such as frescas, are widely consumed.

A single eight-ounce serving of a carbonated soda contains roughly 24 to 30 grams of sugar, and 30% of the adolescents surveyed in this analysis reported consuming sodas two or more times a day. This reflects a large population of adolescents in LMICs whose daily intake from sodas alone, not including other SSBs or other sources of added sugars, puts them above the World Health Organization recommendation of consuming less than 10% of their total daily energy intake from added sugars; it also puts this population well above the World Health Organization ideal of limiting added sugars to less than 5% of their total daily energy intake.

Previous studies have indicated that SSB consumption and disease burdens attributable to SSB consumption are higher in younger adults than older adults, suggesting a possible generational effect in which younger generations have higher intakes than do older generations.^5,6 Results from the analysis by Yang et al. support the idea of this generational effect, which raises particular concern, because if high intakes in youths persist into older ages, the harmful effects of SSB consumption on chronic disease will be compounded by effects of aging, leading to even greater potential future burdens of obesity, cardiovascular disease, and diabetes.

These results also support previous findings that SSB intakes are particularly high in countries in Latin America and the Caribbean, highlighting it as an area of particular concern to policymakers.

POPULATION-BASED MEASURES

A suboptimal diet, including consumption of SSBs, is often seen as an entirely individual choice, when in actuality a multitude of factors are involved, including the availability and price of SSBs versus other beverages such as potable water, marketing and advertising by manufacturers, and overall food environment in the home, neighborhood, school, and workplace, to name a few. Therefore, it is critical that policies to improve diet not be limited to individual-level education of high-risk populations with very poor dietary habits (e.g., very high SSB intakes); these policies must also include population-based measures that can reach entire populations because, as stated in Geoffrey Rose’s Strategy of Preventive Medicine (Oxford, UK: Oxford University Press; 1993), “a large number of people at a small risk may give rise to more cases of disease than a small number who are at high risk.”^(p431)

Policies to reduce consumption of SSBs have been implemented in several diverse populations worldwide, including Mexico, Brazil, South Africa, France, the United Kingdom, US cities (including San Francisco, CA; Berkeley, CA; Philadelphia, PA; and Seattle, WA), and Pacific Island countries (including Fiji, Samoa, Nauru, and French Polynesia). Such policies are an important first step in improving and protecting population health through public policy; however, much remains to be done.

SSBs present a clear target for health policy; however, policies targeting SSBs alone will address only part of the problem. Poor diet is currently ranked as the greatest contributor to morbidity and mortality in 16 of 21 world regions, primarily because of lower than optimal intakes of healthful, whole-food components of diet such as fruits, vegetables, nuts and seeds, and whole grains, as well as higher than optimal consumption of sodium. Policies to limit the sales of SSBs should be balanced by those to increase intakes of fruits, vegetables, and other basic healthful components of diet.

Of course, policy efforts to target SSB intake are more straightforward because SSBs are a single component of the diet, are mostly industrially produced, and provide no nutritive value. Conversely, increasing intakes of fruits, vegetables, whole grains, nuts, seeds, and fish requires investments in improved food systems, sustainable agriculture and aquaculture, and effective governmental policies.

DIETARY AND HEALTH SURVEILLANCE

The analysis by Yang et al. adds to a large body of evidence indicating the need to reduce SSB intake through implementation of effective population-based strategies targeting multiple sectors of society. Their work also highlights the necessity for robust dietary and health surveillance in LMICs. These countries are most heavily affected by the nutrition transition and increases in chronic disease burdens; however, in many LMICs, health surveillance and health care systems were built around treatment of infectious diseases and nutritional deficiencies.

Many LMICs face the double burden of under- and overnutrition both within populations and within individuals. Without robust health systems integrating surveillance, prevention, and management of both communicable and noncommunicable diseases, it will be impossible to evaluate the population-level effectiveness of health policies. The past century has provided remarkable public health success stories, particularly in high-income Western countries. These successes include (1) large reductions in smoking and concordant decreases in lung cancer; (2) reductions in coronary heart disease mortality because of advances in treatment of hypertension and hypercholesterolemia, and improved emergency medical response methods and systems; and (3) reductions in road traffic injuries because of multisectorial improvements, including driver education, improvement of roadways, signage, and infrastructure, and the development of automobile safety requirements.

Similar multisectorial approaches are critical to the primary prevention of chronic diseases in LMICs, and diet as a whole, as well as particular dietary components such as SSBs and sodium, provide prime targets for population-based prevention measures. Emphasis on implementing such policies in LMICs is key, because they encompass the majority of the world’s population and will shoulder ever-larger burdens of chronic diseases if current dietary trends, including SSB consumption, continue.