Obesogenic environment: origin and consequences

Dietary behaviours of young adults born into an obesogenic environment

Young adulthood and obesogenic food environments

The genesis of the obesogenic environment dates back to the early 1980s. All the population has been affected by this food milieu but today’s young adults (18 to 35 year-olds) have never experienced any other type of foodscape. We fi nd their dietary habits shaped by the modern food environment with its abundance of offerings of foods prepared outside the home and ready access to ultra-processed foods. Larger portion sizes have been their social norm with no memory of a time when serving sizes were smaller. Of concern is that in countries such as Australia, Generation Y is becoming more overweight and obese at a younger age than their parents’ generation did1.

Consumption of food and beverage groups associated with promoting or preventing obesity

Among young adults internationally, there is a remarkable similarity in consumption of foods and beverages associated with weight gain and protection from weight gain. Many young adults drink sugar-sweetened beverages, which are implicated in weight gain. Burgers, fries, pizzas, hot dogs, pies, tacos, and fried chicken typically purchased from fast-food outlets heavily feature on the menus of young adults. Fast food consumption is not just restricted to the United States and the United Kingdom. For example, even in an Asian country, we find 44% of young Singaporeans eat these foods on a regular basis, and only one in ten avoids fast foods. By comparison, three in five 50 to 59-year-olds are non-consumers of fast foods2.

When it comes to vegetables, we discover young adults are the worst consumers. Poor intake is a usual scenario across the USA, UK, Australia and many Western European countries like Germany, Italy, and France. Evidence to support the role of vegetable intake in prevention of weight gain is equivocal but ten-year follow-up of a cohort of young adults in the US, showed males eating more vegetables gained less weight3. In an intervention study to prevent incident obesity in overweight young adults, we showed that increased vegetable intake accounted for 20% of weight loss in intervention participants4. Whether vegetables prevent weight gain or not, they certainly have a role in the prevention of cardiovascular disease, stroke and all-cause mortality5.

Foods outside the core food groups, so-called ultra-processed, or extra or discretionary foods, high in saturated fats and sugars, like confectionery, cookies, and cakes are making considerable contributions to energy intakes. In Australia, these foods account for more than one-third of energy intake and in Brazil, ultra-processed foods feature more frequently in young adults’ diets.

Advent of a ‘global dietary pattern’ in young adulthood

During emerging adulthood (19 to 25 year-olds) dissociation from the peer-group pressure of adolescent years grows. The all-engulfi ng pressure dictating their food choices begins to lessen. Young adults are very much a part of a global society, and the interconnectedness of modern communication means highly persuasive, and youth-targeted food advertising has global reach. Overall dietary patterns of young adults within a country show variation but a universal picture of dietary patterns appears despite quite diverse national cuisines. In a sample of Japanese young women, four dietary patterns emerged. One was more traditional i.e. ‘fi sh and vegetables’ with a good nutritional profi le, but a more Western pattern was also found labeled ‘bread and confectioneries’ that contained not only those foods but also sugar-sweetened beverages and cocoa. Findings from two different Brazilian studies indicate that young Brazilians have diets more closely resembling Americans’ diet than do older Brazilians. Furthermore, pattern analysis shows diets ranging from ‘healthy’ and ‘traditional Brazilian’ to an ‘energy-dense pattern’ (including desserts, cookies, chocolates and fried potato among the typical foods) and a ‘bar’ pattern (including animal sourced foods, salty snacks and alcohol). Young adults in Northern Ireland, demonstrated ‘social/drinker’ (including alcohol, white bread, meat dishes), ‘Western’ (soft drinks, crisps and chips), ‘sweet tooth’ (including desserts and confectionery) and ‘healthy’ (fruit and vegetables and brown bread) patterns6. Thus, young adults in each country showed healthy and unhealthy patterns. Research as to why some young adults are more vulnerable to adoption of poor patterns in the obesogenic foodscape should continue. Social determinants, poor food literacy, lack of cooking skills, and food insecurity should be further studied.

It is clear that the social norm for diet in young adults reflects the main characteristics of an obesogenic food environment. Foods high in saturated fat, sugar and sodium and beverages sweetened with sugars are staples of their diets. Inadequate intakes of vegetables by all young adults prevail. In South America, Europe and Asia change from more traditional meal patterns to those typically encountered in the USA is occurring. Whether the dietary patterns of the current generation of young adults continue through their adult lives is yet to be answered.

  1. Allman-Farinelli MA, Chey T, Bauman AE, Gill T, James WP. Age, period and birth cohort effects on prevalence of overweight and obesity in Australian adults from 1990 to 2000. European Journal of Clinical Nutrition. 2008;62(7):898-907.
  2. Whitton C, Ma Y, Bastian AC, Fen Chan M, Chew L. Fast-food consumers in Singapore: demographic profi le, diet quality and weight status. Public Health Nutrition. 2014;17(8):1805-
  3. Quick V, Wall M, Larson N, Haines J, Neumark-Sztainer D. Personal, behavioral and socio-environmental predictors of overweight incidence in young adults: 10-yr longitudinal fi ndings. The International Journal of Behavioral Nutrition and Physical Activity. 2013;10:37.
  4. Partridge SR, McGeechan K, Bauman A, Phongsavan P, Allman-Farinelli M. Improved eating behaviours mediate weight gain prevention of young adults: moderation and mediation results of a randomised controlled trial of TXT2BFiT, mHealth program. The International Journal of Behavioral Nutrition and Physical Activity. 2016;13:44.
  5. Oyebode O, Gordon-Dseagu V, Walker A, Mindell JS. Fruit and vegetable consumption and all-cause, cancer and CVD mortality: analysis of Health Survey for England data. Journal of Epidemiology and Community Health. 2014;68(9):856-62.
  6. Allman-Farinelli M, Partridge SR, Roy R. Weight-Related Dietary Behaviors in Young Adults. Current Obesity Reports. 2016;5(1):23-9.
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