Population Nutrition

Metabolic Disease Epidemic

Facts, figures and definitions 2
Burden of Disease attributable to Non-communicable Disease 4
Factors contributing to obesity and metabolic disease 5
Approaches to obesity prevention 9
Obesity prevention and the nutrition transition 12
Summary of key points 14
Conclusion 14
References 15
Introduction
This module will consider the prevalence, causes, and potential public health actions to address the metabolic disease epidemic, which is occurring in Australia and internationally. The term ‘metabolic disease’ refers to diseases that have interrupted normal metabolic function, and includes obesity, particularly abdominal obesity, impaired glucose tolerance, insulin resistance, type 2 diabetes, and altered lipid profiles known to be associated with increased vessel damage. The metabolic disease epidemic is an important current issue in public health nutrition due to the high prevalence in developed countries, the increasing prevalence associated with the Nutrition Transition in developing countries, and the challenges associated with addressing the issues. These diseases place enormous economic costs on the health care systems of all countries, and are among the greatest contributors to global morbidity and mortality.
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Objectives
When you have completed this module, you should be able to:
• Discuss why the metabolic disease epidemic is a public health nutrition priority,
• Describe and assess what contributes to the development of metabolic disease at a population level and groups most at risk, and
• Discuss what public health approaches can and should be undertaken to reduce the rising prevalence of metabolic disease across the population.
Facts, figures and definitions
The terms described below are relevant to understanding the metabolic disease epidemic. The Deakin university unit ‘Diet and Disease’ (HSN301 or HSN703) provides more detail on the conditions outlined below – if you have undertaken one of those units then this first section (two pages) should serve to refresh your knowledge, and if you have not then you are encouraged to read some of the references in more detail.
•A term used to describe the series of demographic, social and economic changes occurring in low and middle income countries, which result in rapid shifts in dietary patterns and lifestyles. In countries undergoing nutrition transition, communicable diseases and under-nutrition co-exist with an increasing prevalence of non-communicable and metabolic diseases and over-nutrition -the worst of both worlds. The nutrition transition is discussed in further detail later in this module.
Nutrition transition
•Metabolic conditions which are non-infectious and non-transmittable (as opposed to communicable diseases, which are infectious). This term refers to similar states of ill health as the term ‘metabolic disease’, but also includes Cardiovascular Disease (CVD), cancers and respiratory disease. Non communicable diseases are usually chronic in nature (long duration) and most are linked to obesity. These health issues are estimated to be the leading cause of death in the world, representing 63% of deaths annually, with 80% of these occurring in low-and middle-income countries (WHO).
Non communicable diseases (NCDs)
•Obesity is typically defined as a Body Mass Index (BMI) = 30, though some definitions also incorporate other measures such as waist circumference (indicating abdominal obesity) and percentage body fat. People who are obese, or overweight (BMI 25-29.9), are at higher risk of Type 2 Diabetes, cardiovascular disease, cancer, joint problems, respiratory problems and some psycho-social issues. According to the World Health Organisation (2014) there are around 2 billion adults overweight, of those 768 million are obese.It is also estimated that over 200 million school-age children are overweight, making this generation the first predicted to have a shorter lifespan than their parents (World Obesity).
Obesity
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According to the 2011-12 Australian Health Survey,
In these Australian data overweight/obesity rates varied across different population groups. The rate was higher for men (70.3%) than women (56.2%), and higher for older people (74.7% of adults aged 65-74) than younger people (38.4% of adults aged 18-24) in the 2011-12 survey. Additionally, according to previous data, a third of Australian adults living in areas of most disadvantage were obese (33%), which is almost double that of people in areas of least disadvantage (17%). Where people lived also influenced prevalence with more adults in outer regional and remote Australia being obese (31%) than those in major cities (23%). These figures reflect some of the greater health risks seen for disadvantaged groups, as discussed in Module 3.
Figure 1: Overweight/Obesity rates across different population groups in Australia
Older people -65-74 years (74.7%)
Younger people -18-24 years (38.4%)
Men (70.3%)
Women (56.2%)
Outer regional and rural areas (31%)
Major Australian cities
(23%)
Most disadvantaged (33%)
Least disadvantaged (17%)
“In 2011-12, 63.4% of Australians aged 18 years and over were overweight or obese, comprised of 35.0% overweight and 28.3% obese. A further 35.2% were of normal weight and 1.5% were underweight”. “Prevalence of overweight and obesity in adults aged 18 years and over has continued to rise to 63.4% in 2011-12 from 61.2% in 2007-08 and 56.3% in 1995. However the prevalence of overweight and obesity in children aged 5-17 has remained stable at 25.3% in 2011-12.” (ABS)
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Burden of Disease attributable to Non-communicable Disease
The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) is a large and detailed collection and representation of data to quantify levels and trends in health. The GBD provides a tool to quantify health loss from hundreds of diseases, injuries, and risk factors. GBD research incorporates both the “prevalence” of a disease or risk factor and the “relative harm” it causes. The Australian data indicates that:
• Non-communicable diseases are the leading contributors to burden of disease
• High body mass index and dietary risks now both out-rank tobacco smoking as the top risk factors contributing to the burden of disease
• Go here to view the Australian data and here to look at the whole GBD program and compare with other countries.
•Diabetesis diagnosed when a person’s insulin response to carbohydrate ingestion is significantly impaired.Globally there are 374 million people living with diabetes, with an estimated further 50% undiagnosed. Most of these cases are type 2 diabetes, which is caused by ‘lifestyle factors’ including physical inactivity, unhealthy diet, and overweight/obesity.People with diabetes are at higher risk of health conditions such as cardiovascular disease, kidney failure and eye disease. In Australia, diabetes is the 6thleading cause of death and contributes 10% to all deaths. Those living in disadvantaged areas are twice as likely to have diabetes as those living in least disadvantaged areas. For further information on diabetes in Australia, please see the Diabetes Australia website (https://www.diabetesaustralia.com.au/diabetes-in-australia).
Diabetes
•Cardiovascular disease comprises diseases and conditions of the heart and blood vessels. Globally, it is estimated that 17.3 million people died from CVD in 2008, with a projected figure for 2030 of 23.6 million. Given CVD is known as a disease of affluence it is perhaps surprising to find that the majority of deaths (80%) are seen in lower to middle income countries. (WHO: http://www.who.int/cardiovascular_diseases/en/). In Australia, according to the 2011-12 Australian Health Survey, 1 million people (4.7%) reported having CVD.
Cardiovascular disease (CVD)
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Essential Task 4.1: Read
Read Nader P, et al. 2012, Next Steps in Obesity Prevention: Altering Early Life Systems to Support Healthy Parents, Infant and Toddlers, Childhood Obesity, vol. 8, no. 3. pp. 195-204.
This paper should firstly reinforce and extend your knowledge from Module 1 regarding the importance of early influences across the lifecourse, and developmental and intergenerational effects. Take note of any new information about the lifestages considered most important for obesity prevention.
Following this, you are encouraged to consider:
– What are some key features of a systems approach?
– Look at the model (figure also shown below), and take note particularly of the two way (bidirectional) arrow between the individual/family and social and physical environment support.
– What are some relevant/useful examples of systems interactions for nutrition promotion and obesity prevention?
Factors contributing to obesity and metabolic disease
This infographic from the Institute of Medicine titled Obesity: complex but conquerable presents some key facts and figures on obesity, particularly on five contributing factors – suggested as areas which need improvement.
Another infographic from the Obesity Society titled Potential Contributors to Obesity illustrates the complexity of the determinants of obesity and presents a more detailed lsit of factors that have been raised in the literature as potential contributors.
This complexity of the genesis of obesity is nicely summarised by Deakin’s Head of the School of Exercise and Nutrition Sciences Professor David Crawford:
“The obesity epidemic is a complex phenomenon (and) this complexity exists at a number of levels… The underlying influences on our eating and physical activity are not straightforward, involving a range of personal, social and structural factors that are likely to vary in their relative importance for different populations and for different sub-groups within the same population. In addition, there are powerful global commercial and political interests at stake.” (Crawford et al, 2010.)
The complexity referred to has been operationalised by many researchers (if you are interested in this topic for postgraduate study, a potential unit of interest is HSN734 Obesity Prevention). In the following reading you’ll find both a discussion around a focus for obesity prevention but also an example of a model that could be applied to ensure obesity and its sequelae might be addressed.
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Essential Task 4.2: Read
Please read this paper by Giskes et al, an interesting systematic review looking at which environmental factors significantly contribute to the development of overweight/obesity. Please note which ones were the strongest drivers for obesity. Giskes K et al. 2011, A systematic review of environmental factors and obesogenic dietary intakes among adults: are we getting closer to understanding obesogenic environments? Obesity Reviews, vol. 12, no. 5. e95-e106.
A community systems framework of early intervention of childhood obesity with feedbacks between individuals and the environment (Nader et al. 2012).
The complexity referred to by Crawford above has also been operationalised by Davidson and Birch’s socio-ecological model (figure shown below). The socio-ecological model highlights a similar but slightly different conception of causality suggesting that obesity and metabolic disease will be affected by individual, interpersonal, and environmental factors. The figure below focusses
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Supplementary Task: Read
This paper provides a fascinating insight into a key element of the food environment: ultra-processed foods. Monteiro C et al. 2013, Ultra-processed products are becoming dominant in the global food system, Obesity Reviews, vol. 13, no. S2, pp. 21-28.
The discussion of the spread of these foods to middle-income countries is linked to the discussion of the nutrition transition at the end of this module.
on how these different levels can influence the weight status of a child, but a similar model can be applied to a variety of health outcomes and life stages.
The environmental or ecological drivers affecting food choice and physical activity can include:
The food environment includes the type of food that is available, the cost of food, how it is marketed, and policies regulating the food supply. The food environment is becoming increasingly globalised, with highly processed foods transported around the world and often available for relatively low prices. The international nature of the food environment makes regulation challenging because of differences between countries, and because trade agreements related to food are usually focused on economic and political rationale, thus unrelated to nutrition.
The built environment includes the type of buildings, neighbourhoods, transportation systems, and other man-made features of the landscape e.g. roads, pavements, buildings, sports facilities, parks, escalators/stairs. These features affect people’s ability to participate in physical activity (eg.
Source: Davison KK, Birch LL. Childhood overweight: a contextual model and recommendations for future research. Obes Rev. 2001;2:159–71
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Supplementary Task: Watch
You might find it interesting to watch this short (~10 minute) video with Dr William (Bill) Dietz, discussing the issue of obesity in the United States – in particular issues related to inequalities, the likely key dietary factors contributing to the issue of obesity, and some examples of strategies to address these.
If there are no safe, well-lit footpaths it is difficult to walk anywhere), as well as the ability of people to access food (eg. If there is no reliable transport to shopping centres, people may rely on convenience food stores closer to home).
This cartoon is an amusing reminder with a serious message about the obesity-promoting nature of the current environment.
Source: The Age newspaper, 2012
In addition to environmental factors which affect food choice and physical activity, the socio-ecological model also shows that interpersonal and individual factors are likely to be important. The skills, knowledge, perceptions and attitudes of individuals, and those of their friends and family, will shape the way a person eats. For example, if a parent has a high level of nutrition knowledge, cooking skills, and self-efficacy to eat well, then they are likely to have a good quality diet and consequently be a healthy weight. Also, if the parent models healthy eating and eats with the child, uses appropriate feeding practices, and has healthy foods available in the home, then their child is also likely to eat and enjoy healthy foods throughout their life (Spence et al., 2010).
Conversely, there are many individual and interpersonal factors which do not promote healthy eating and are therefore associated with obesity. Many people have limited knowledge and skills of how to prepare tasty and nutritious meals. Lack of time, financial difficulties, stress, and lack of motivation to eat well and promote health are all common reasons for people to regularly eat unhealthy, processed foods. Considering ways to address these factors at a population level is another important aspect of public health nutrition.
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Approaches to obesity prevention
If preventing obesity were easy we’d have prevented the obesity epidemic we currently face. Clearly, and as this module highlights, preventing population obesity is not simple and there is much to be done. In this section we consider a number of approaches to obesity prevention, with a focus on complex systems thinking. The over-riding philosophy remains that complex problems will require complex solutions with co-ordinated action occurring at multiple levels. This section discusses some examples of current strategies – as with all the issues presented in this unit, a variety of strategies is required to address the variety of issues across different populations, and different experts have different views about which approaches are “best”. You can use these activities to inform your own viewpoint about the most useful strategies (and as an opportunity for you to consider whether any of these areas might appeal to you as career, advocacy or research options in future).
Examples of settings and strategies for nutrition promotion for obesity prevention are listed below, and then some are discussed in more detail with further examples. Please note this is by no means a finite list, and there are many other types of strategies and settings – you might like to add to this list with other examples that you know of.
Type of strategy/setting
Example of nutrition promotion in action
Point-of-sale information and availability
Traffic-light labelling
Health star rating system (some commentary here)
Financial incentives and pricing strategies
Mexican tax on sugar sweetened beverages
‘Fat tax’ as per Smed & Robinson reading task 4.8 below
Community-based programs
Bell et al. Preventing childhood obesity: the sentinel site for obesity prevention in Victoria, Australia, HPI.
Healthy Together Victoria
Schools
Healthy Kids Eat Well Get Active
Sports clubs
Be the influence
Government resources
Healthy Weight Guide
Mass media campaigns
See essential task 4.7 below
Some strategies are implemented within a single organisation, while others are implemented systematically through a particular sector. The National Healthy School Canteens Project is an example of a strategy with the potential for wide reach across the nation. While such a strategy does not necessarily mean that all schools immediately follow new healthy food and drink
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Essential Task 4.3: Read and think
Please read this short article discussing and comparing nutrition promotion strategies which rely on educating and upskilling the individual to make changes, versus strategies which change the environment. Adams et al. Why Are Some Population Interventions for Diet and Obesity More Equitable and Effective Than Others? The Role of Individual Agency, PLOS Medicine 2016.
Create a list of the pros and cons of interventions requiring more agency (individual responsibility) versus less agency (use the paper as a starting point, but add to your list with your own experiences and knowledge and opinions).
Then, while you are working through all the remaining tasks in this section, think about how much agency (individual responsibility) is required for each of the very different initiatives discussed to be effective.
Essential Task 4.4: Read and think
Access this 2016 report of the Commission on Ending Childhood Obesity. Open the report and read the Executive Summary, pages VI to XI (8 -13 in your PDF viewer). Despite the complexities of the issue of obesity discussed earlier, you will note that this report has managed to define a list of very specific suggested strategies, which have the strongest evidence base to support reductions in childhood obesity.
As you are reading (particularly pages VIII & X related to nutrition strategies), consider how easy or difficult it might be to implement each strategy. For example, consider:
• Who might some of the stakeholders be, and are they likely to agree on strategies (especially when food industry is involved)?
• How many different settings and systems would be involved to implement the strategy?
• How expensive would it be? Who would pay?
• How popular would it be?
• How far removed is this from current practice? In Australia and internationally?
guidelines, it does give impetus and start the process of improvements. Where such strategies are supported by appropriate resources from the government, there is potential for benefit across the population of school-aged children.
You might like to discuss your responses to this activity on the CloudDeakin discussion
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Essential Task 4.8: Read and Think
Please read the short, 2 page article by Smed & Robinson 2012 which discusses the implementation of a ‘fax tax’ in Denmark. Smed, S, & Robinson, A,(2012 ) ‘Are taxes on fatty foods having their desired effects on health?’, British Medical Journal, 2012, vol. 345: e6885.
This tax was implemented in 2011, and then abolished in 2012 – you may wish to look at some of the commentaries and viewpoints available about this issue online.
Write down some pros and cons for using a tax on some foods in Australia as a public health nutrition strategy.
Essential Task 4.6: Watch
Please watch the video with A/P Karen Campbell for a description of why early childhood is a particularly important stage to target for obesity prevention. Karen will also discuss the Infant Program, an example of a community-based intervention targeting individual and interpersonal influences on obesity at this life stage.
Essential Task 4.5: Healthy Together Victoria
View: Revisit the Healthy Together Victoria: Complex Systems Thinking video, approx. 3 mins.
Visit: Healthy Together Victoria home page and take a good look around and consider the complexity of the response to obesity prevention in Victoria in 2013-2015.
View: Please watch this video interview with Debbie Leslie, about her experience working in health and nutrition promotion in Whittlesea, and the Healthy Together Victoria initiative.
Future thoughts: Evaluation of the Healthy Together Victoria program is currently taking place. Look out for these results in coming years, which will be informative for future systems health promotion efforts.
Essential Task 4.7: Watch and think
Briefly review strategies such as the Live Lighter campaign, and ads to Reduce soft drink consumption:and Set a better example. These promote individuals to modify behaviours such as reduce their portion sizes and spend more time in active outdoor pursuits.
What do you think are some strengths and limitations of such initiatives? What are they likely to achieve (effect, target audience reach, would you change your behaviour after seeing one of these ads?) How do they compare to some of the other strategies mentioned below?
Debbie is another Deakin alumni, who shares with us her experiences in the health promotion field at an early stage of her career.
You might like to discuss your responses to this activity on the CloudDeakin discussion board.
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Supplementary Task: Online
If you are interested in further information on food policies, there is a great 17 minute audio clip of an interview between Kelly Brownell and Jane Martin (Obesity Policy Coalition Australia) online, see: https://itunes.apple.com/itunes-u/the-rudd-report/id341653648#ls=1 (click on ‘Pricing and Food Marketing in Australia’ number 41 on the list).
There are also other units offered by Deakin University focused entirely on food policy, which you might consider studying – HSN706 (postgraduate) and HSN309 (undergraduate).
Supplementary Task: Online
Visit some websites to find about more about obesity prevention advocacy in Australia. For example:
• Parents’ Voice
• Obesity Policy Coalition
• Public Health Association of Australia
Supplementary Task: Online
Swinburn B, Wood A 2013, Progress on obesity prevention over 20 years in Australia and New Zealand, Obesity Reviews, vol. 14, no. 2, pp. 60-68 – this paper discusses lessons learned from over 20 years of obesity prevention efforts in Australia and New Zealand, and suggests directions for future efforts.
Obesity prevention and the nutrition transition
Obesity and its consequent diseases affect most countries around the world. Stunningly, countries such as Mexico, where stunting and malnutrition remain prevalent are also showing some of the highest rates of obesity in the world. This paradoxical situation, seen in many poorer countries has come to be known as the nutrition transition. Professor Barry Popkin introduced this notion to the world and his work is profiled in the Globesity documentary recommended below.
In low- and middle-income countries experiencing an increase in wealth, obesity tends to occur firstly in women before men, and in those of middle age before younger people and children. It is first predominant in people living in urban areas of higher socio-economic position. Over time, as economic development continues in these countries, the proportion of people who are underweight decreases, and the proportion of overweight increases. As the nutrition transition continues, overweight and underweight often coexist together, before obesity eventually becomes more common in the lower socio-economic population groups.
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Supplementary Tasks
Read: Popkin B, Adair L and Ng S. 2012 Global nutrition transition and the pandemic of obesity in developing countries. Nutr Rev.70(1):3-21, for a summary of this issue by expert Barry Popkin.
Read: Kelishadi R, 2007, Childhood overweight, obesity and the metabolic syndrome in developing countries, Epidemiological Reviews, vol. 29, pp. 62-76, for a discussion of the impacts of the nutrition transition on children’s health.
View: Globesity – Fat’s New Frontier, Foreign Correspondent, ABC, 1hr.
View: BBC documentary Horizons program via EduTV, ‘The nine months that made you’, 52 mins.
Reflect: What stays with you after viewing these videos? What are the take home
Essential task 4.11: Think
Consider how your learnings from this module intersect, align with, or oppose, your learnings from the other modules studied in this unit so far. As some prompts:
– Why is investigation of the nutrition transition important, even if obesity rates in many mid- or low-income countries are not as high as those in developed countries?
– How can nutrition promotion messages regarding all the topics studied so far (food sustainability, food security and obesity) all align?
Essential task 4.10: View and think
Look at this WHO website which hosts data regarding global obesity rates. Explore the functions available. Suggest which countries may be going through nutrition transition. (This website allows you to map both underweight and overweight/obesity. Note not only the prevalence, but also which countries do not have sufficient data for inclusion.)
Essential task 4.9: Read
1. A special edition on the nutrition transition was published in the journal Public Health Nutrition in 2013. Please ensure you read the short editorial: The nutrition transition: the same, but different.
You are also encouraged to view the full table of contents for this issue, and read any of the further papers mentioned in the editorial which are of interest.
2. Read: Rivera J et al. 2013, Childhood and adolescent overweight and obesity in Latin America: a systematic review, Review, vol. 2, published online December 13, 2013. The authors state: “Policies in most countries favour prevention of undernutrition” – while reading this paper consider some of the reasons WHY this might be the case.
Let’s discuss your responses to this task in the module 4 online tutorial in week 8.
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Summary of key points
The metabolic disease epidemic is an important current issue in public health nutrition due to the high prevalence in developed countries, the increasing prevalence associated with the nutrition transition in developing countries, and the challenges associated with addressing the issues.
Obesity rates vary across different population groups, and are higher in more disadvantaged groups, highlighting the need for considerations of equity when addressing this issue.
Factors contributing to obesity and metabolic disease are complex – it is important to understand these in order to propose appropriate interventions to address the issue(s)
Solutions and interventions to address metabolic disease are therefore also often complex – action is probably needed in a variety of sectors using a variety of strategies. It is important to be aware of some of the opportunities and evidence-based suggestions for action, and to consider the amount of personal or public responsibility, and ‘agency’ required for the various intervention types to be effective.
Obesity and its consequent diseases affect most countries around the world. Some countries where stunting and malnutrition remain prevalent are also showing some of the highest rates of obesity in the world. This paradoxical situation, seen in many poorer countries has come to be known as the nutrition transition, and is a key current issue in public health nutrition.
Conclusion
Metabolic disease is a major contributor to global disease burden, and is in large part a consequence of poor nutrition. There are many complex and interconnected factors which contribute to the current metabolic disease epidemic. It is an important current issue in public health nutrition due to the high prevalence in developed countries, the increasing prevalence associated with the nutrition transition in developing countries, and the challenges associated with addressing the issues. Public health nutritionists must work with other sectors, utilise available examples and evidence, and apply complex systems theories to understand and address the multifaceted and interconnected factors that influence dietary intake.
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References
Australian Bureau of Statistics: http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/4364.0.55.001Chapter4002011-12
Australian Institute of Health and Welfare. Public health expenditure in Australia, 2008-9. Accessed 22/02/13 from www.aihw.gov.au/public-health-expenditure/
Campbell, K., et al. The Infant Feeding Activity and Nutrition Trial (INFANT) an early intervention to prevent childhood obesity: Cluster randomised controlled trial. BMC Public Health, 2008; 8: 103.
Clark R, Armstrong R and Waters E. Local government and obesity prevention: An evidence resource. Interventions to prevent obesity in early years settings; tackling food insecurity and built environment changes to support physical activity. 2010; CO-OPS Secretariat, Deakin University, Geelong.
Crawford D., Ball K., Jeffery RW., and Brug J. P445 from: Obesity epidemiology, from aetiology to public health, second edition, Oxford University Press, 2010.
International Obesity Taskforce 2010. Accessed 22/02/12 from http://www.iaso.org/iotf/obesity/obesitytheglobalepidemic/
Spence A., Campbell, K., Hesketh, K. Parental correlates of young children’s dietary intakes: a review. Australasian Epidemiologist, 2010; 17(1): 17-20.
World Health Organization. Accessed 22/02/13 from http://www.who.int/features/factfiles/noncommunicable_diseases/en/

Metabolic Disease Epidemic