|Year : 2016 | Volume
| Issue : 1 | Page : 22-26
Population-based dietary approaches for the prevention of noncommunicable diseases
Noel P Somasundaram1, Nishan Sudheera Kalupahana2
1 Diabetes and Endocrine Unit, National Hospital of Sri Lanka, Colombo, Sri Lanka
2 Department of Physiology, Faculty of Medicine, University of Peradeniya, Sri Lanka
|Date of Web Publication||18-May-2017|
Noel P Somasundaram
Diabetes and Endocrine Unit, National Hospital of Sri Lanka, Colombo 10
As the incidence of noncommunicable diseases such as diabetes continues to rise at an alarming rate in South-East Asia, it is imperative that urgent and population-wide strategies are adopted. The most important contributors to the rise in noncommunicable disease are a rise in mean caloric intake and a decrease in physical activity. The evidence for population-based dietary approaches to counter these factors is reviewed. Several structural and cohesive interdepartmental coordination efforts are required for effective implementation of prevention strategies. Since low- and middle-income countries may lack the frameworks for effective and integrated multi-stakeholder intervention, implementation of population-based dietary and physical-activity approaches may be delayed and may be too late for effective prevention in current at-risk cohorts. Evidence-based strategies to decrease energy intake and increase physical activity are now well established and their urgent adoption by Member States of the World Health Organization South-East Asia Region is essential. In the context of Sri Lanka, for example, it is recommended that the most effective and easy-to-implement interventions would be media campaigns, restrictions on advertisement of unhealthy foods, taxation of unhealthy foods, subsidies for production of healthy foods, and laws on nutrition labelling that introduce colour coding of packaged foods.
Keywords: best buys, food taxation, NCD, noncommunicable diseases, obesity
|How to cite this article:|
Somasundaram NP, Kalupahana NS. Population-based dietary approaches for the prevention of noncommunicable diseases. WHO South-East Asia J Public Health 2016;5:22-6
|How to cite this URL:|
Somasundaram NP, Kalupahana NS. Population-based dietary approaches for the prevention of noncommunicable diseases. WHO South-East Asia J Public Health [serial online] 2016 [cited 2020 Jul 9];5:22-6. Available from: http://www.who-seajph.org/text.asp?2016/5/1/22/206548
| Background|| |
Noncommunicable diseases (NCDs) such as cardiovascular disease, diabetes and cancers are on the rise worldwide. This rise in NCDs will have a huge social impact, as well as causing exponential increases in the economic costs incurred as a result of secondary prevention and treatment of complications. The highest quantum of rise in NCDs is seen in low- and middle-income countries (LMICs) that already struggle with health allocations and parity of access to the poor. Poverty and barriers in access to health care, together with delays in responding to the rising and changing health-care requirements, can overwhelm the health budgets of most countries. Member States of the World Health Organization (WHO) South-East Asia Region, such as those in India, Maldives and Sri Lanka, show particular vulnerability, with NCDs causing a high proportion of deaths.
There are two major problems in implementation of effective NCD-prevention interventions. Firstly, NCD intervention strategies can be complex and costly. Most LMICs do not have the framework for the effective and integrated multi-stakeholder intervention that is required. Therefore, despite having NCD policies, their implementation is often inadequate. Secondly, there is a time delay in implementation of programmes, and this delay will allow the incidence of NCDs to rise. An example is that of prediabetes. In many countries, 40–50% of the population has dysglycaemia and more than half of these people have prediabetes., By the time system interventions take effect, the individuals with prediabetes will have progressed to diabetes; the number of cases of diabetes can double in one to two decades.
| Causal Factors for the Current Pandemic of Noncommunicable Diseases|| |
The risk factors for most NCDs can be broadly classified into metabolic and behavioural. The former include risk factors such as hypertension, overweight/obesity, hyperglycaemia and hyperlipidaemia, while the latter include tobacco use, physical inactivity, unhealthy diet and misuse of alcohol. It is likely that behavioural factors such as physical inactivity and unhealthy diet increase the risk of NCDs, via an increase in risk for the metabolic risk factors, mainly obesity. Indeed, the increasing prevalence of NCDs such as cardiovascular disease and type 2 diabetes is associated with an increasing prevalence of obesity. In individuals of South Asian descent in particular, the risk for NCDs such as type 2 diabetes starts at a lower body mass index when compared to Caucasians. Moreover, owing to nutrition transition, the annual increase in the prevalence of obesity in LMICs is greater than that in high-income countries. Therefore, urgent action is needed to prevent the escalation of obesity and NCD rates in LMICs. An understanding of the causes of obesity is essential for the development of strategies to treat and prevent obesity, which would help to alleviate the risk for NCDs.
| Causes of Obesity|| |
Body weight is determined by the balance between energy intake and expenditure. Energy intake is from the ingestion of carbohydrates, proteins, fat and alcohol, while energy expenditure is through resting metabolic rate, the thermic effect of food and physical activity. When the energy intake exceeds energy expenditure, a state of positive energy balance occurs, leading to an increase in body weight, of which 60% to 80% is usually body fat. Homeostatic mechanisms for energy balance prevent wide fluctuations in body weight. Despite the evidence for these homeostatic mechanisms, most people gain weight over their adult years. This suggests that there may be limits to the body’s ability to match energy intake and expenditure, especially under changing environmental conditions. For example, data from the National Health and Nutrition Examination Survey suggest that the average daily energy intake in the United States of America (USA) increased by 168 kcal/day for men and 335 kcal/day for women between the years 1971 to 2000. Without mechanisms for energy balance, this increase would theoretically give rise to a yearly weight gain of 8 kg for men and 16 kg for women. Similarly, there is evidence that energy expenditure has also decreased over time. For example, Church et al. have reported that occupational physical activity in the USA has declined by 142 kcal/day since 1960, which in theory would increase body weight by about 7 kg per year. Taken together, the changes in energy intake and energy expenditure over the past decades would predict more weight gain in adults than has actually occurred, if there were no physiological homeostatic processes attempting to maintain energy balance. Therefore, the recent escalation of obesity rates is likely to be due to a combination of increased energy intake and reduced energy expenditure, which have exceeded the body’s limits of homeostatic mechanisms for energy balance. This is an important consideration when developing interventions targeted at both preventing and reversing obesity.
From the perspective of energy balance, it would be easier to prevent obesity than to reverse it, since physiological regulatory mechanisms defending body weight appear to respond much more strongly to weight loss than to prevention of weight gain. Thus, it would be easier to prevent weight gain than to produce sustained reductions in body weight in those who are already obese. Compensatory reductions in resting metabolic rate and increases in hunger occur during energy restriction and weight loss. However, simply preventing positive energy balance should not produce significant compensation through increased energy intake or a reduction in resting metabolic rate. Therefore, a reasonable starting point in addressing obesity is to develop behaviour goals for primary prevention of weight gain. According to different predictive methods, weight gain in adult and child populations could be prevented by an energy deficit of 100 kcal/day and 150 kcal/day respectively. Therefore, population-based strategies for prevention of weight gain need only advocate small changes in physical activity and energy intake to be successful. Such programmes could concentrate on helping people to reduce the energy density and portion size of some foods consumed and increasing lifestyle physical activity.
| Evidence-Based Strategies to Decrease Energy Intake and Increase Physical Activity|| |
Shifts in dietary patterns in Member States of the WHO South-East Asia Region, particularly with respect to greater intake of fat, sugar and foods from animal sources, appear to have contributed to the increase in energy intake in recent years., According to Duffey and Popkin, the number of eating/ drinking occasions per day, portion size per eating occasion, and energy density per eating/drinking occasion are the largest contributors to annualized changes in daily total energy among US children between 1977 and 2010. The energy density of meals is highly dependent on the fat and sugar content in the food. Therefore, effective strategies to reduce the energy density of meals include increasing the consumption of fruit and vegetables and cutting down the consumption of high-fat food and sugary drinks. Reducing portion sizes is also an important strategy in this regard. All these aforementioned changes are behavioural ones, which require population-based interventions to succeed.
A recent review by the American Heart Association of population-based approaches to improving diet and physical activity has identified key evidence-based areas, which are summarized in [Table 1] and [Table 2]. These are broadly classified into media and education, labelling and information, economic incentives, schools, workplaces, local environment, and restrictions and mandates. Since the resources for these interventions are limited, it is important to identify the “best buys” from among them. These are discussed next.
Feasible population-based dietary options for the prevention of noncommunicable diseases in Member States of the South-East Asia Region: “best buys”
The WHO South-East Asia Region has been an emerging frontier for the food industry, which is aggressively marketing to increase the sale of their unhealthy products. Low cost and easy availability of convenience foods have also influenced many South-East Asian populations, particularly in urban areas, to increasingly consume high-saturated-fat snacks, refined carbohydrates and sweetened carbonated beverages. Further, evidence from studies indicates that knowledge about food and healthy food behaviours is inadequate among populations in this region., Media and education campaigns are successful evidence-based strategies in delivering health messages on increasing the consumption of healthful foods such as fruit and vegetables, or reducing consumption of less healthful foods such as high-fat foods and sugary drinks. This strategy can also be used to educate the public to reduce portion sizes. One method to combine both of the above is to introduce a “plate method”, which focuses on both reducing the energy density of food (half the plate should be vegetables) and decreasing portion sizes (only one quarter of the plate should be grains/starches). Media and education campaigns are particularly relevant in South-East Asian countries, considering that much of the food eaten in this region is from the informal sector, such as from street vendors, and therefore beyond the control of labelling strategies or marketing restrictions.
However, media and education campaigns need to be supplemented by other strategies, such as labelling of packaged foods. Labelling is another strategy to increase public awareness, as well as to modify the behaviour of the food industry. This strategy includes mandating panels showing nutrition facts on packaged food items. An additional strategy would be to colour code foods based on the “healthfulness” of the food item. This strategy, however, would need legislative changes by the government. Education campaigns can also be used for increasing physical activity with minimal cost. An example is the display of point-of-decision prompts to encourage the use of stairs instead of elevators. At present, nutrient labelling of packaged foods is voluntary in most Member States in the South-East Asia Region and front-of-pack labelling is only practised in Thailand.
|Table 1: Summary of evidence-based population approaches to promoting healthy diets|
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|Table 2: Summary of evidence-based population approaches to improving physical activity|
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Economic incentives are also important in changing consumer behaviour. These include providing subsidies to lower the prices of healthful foods such as fruit and vegetables, since the relatively high cost of fruit and vegetables in many countries discourages consumption of such healthy food items. Providing concessions to the agriculture sector to create an infrastructure that facilitates production, transportation and marketing of healthier foods, sustained over several decades, would be important in maintaining a constant supply of these foods.
Tax strategies to increase the prices of less healthful foods and beverages is another method to increase the price of unhealthy foods and reduce their consumption. For example, a recent economic-epidemiologic modelling study showed that sustained taxation of sugar-sweetened beverages at a high tax rate could mitigate rising obesity and type 2 diabetes in India among both urban and rural subpopulations.
Schools and workplaces are important sites for implementation of interventions to prevent NCDs. Providing specialized educational curricula including healthful behaviours, training teachers on NCD prevention, and providing healthy food and beverage options at schools are important strategies in this regard, and have been shown to be successful., To increase physical activity in schoolchildren, it is important to increase the availability of school playground spaces and equipment.
Increasing physical education (PE) classes and having trained PE teachers at schools are important ways by which physical activity can be increased without much expense. Having regular classroom physical activity breaks during academic lessons could also be important in breaking long spells of sedentary behaviour. Workplace “best buy” interventions include providing access to healthy food options, providing a set time for physical activity during work hours and adding new, or updating, worksite fitness centres.
Restrictions and mandates are also important strategies that a government can enforce to promote healthy behaviours. This includes restrictions on television advertisements for less healthful foods or beverages advertised to children and restrictions on advertising and marketing of less healthful foods or beverages near schools and public places. However, WHO’s recommendations on restricting the marketing of unhealthy foods and sugar-sweetened beverages have not yet been implemented in Member States of the South-East Asia Region. Recommending general nutrition standards for foods and beverages marketed and advertised to children is another strategy to cut down consumption of high-energy foods by children. Finally, regulatory policies to reduce specific nutrients in foods (e.g. trans fats, salt, sugar) is another method to reduce consumption of these nutrients.
Making changes to the local environment is an important strategy by which physical activity can be increased. While it can be argued that this incurs a huge cost, incorporation of these strategies to new constructions can overcome this problem. Improved accessibility of recreation and exercise spaces and facilities (e.g. building of parks and playgrounds, increasing operating hours, use of school facilities during non-school hours), improved pavement and street design to increase active commuting (walking or cycling) to school by children, improved traffic safety, improved neighbourhood aesthetics (to increase activity in adults) and improved walkability are some of the areas that can be addressed to increase physical activity.
| Opportunities and Challenges to Implementation: The Example of Sri Lanka|| |
NCD interventions must be urgent and simple, in order to be effective. The “best buy” model is to implement the most cost-effective approach. However, “best buys” that have been considered are themselves too complex and require multiple departments and ministries in various levels of governance to come together to implement the model as a cohesive unit. Therefore, it is important that the “best buy” is actually the simplest as well as the most cost-effective approach and can be implemented with the fewest structural changes in the particular country.
For example, in the context of Sri Lanka, we recommend that the most feasible approaches are: media campaigns, restrictions on advertisement of unhealthy foods, taxation of unhealthy foods, subsidies for production of healthy foods, and laws on nutrition labelling that introduce colour coding of packaged foods. In Sri Lanka, the mass media, especially the electronic media, play a significant role in making the public aware of current issues, which can have an impact on public behaviour. Moreover, these media organizations are involved in mobilizing the public in issues of national significance. For example, several media organizations were at the forefront of collecting and delivering aid to the individuals affected by the 2004 tsunami. In this context, media campaigns on health promotion, as well as restriction of advertisement of unhealthy foods, would be of paramount importance. Food taxation, although not very popular, has been shown to be effective in decreasing the consumption of foods that have been targeted. The taxation has to be transparent and implemented with consultation of the population, and, in order to be effective and acceptable, the taxation of food should not be seen as revenue earning but as encouraging and rewarding a switch to alternative healthy foods. The tax should be applied not just for foods where caloric sweetener has been added but for all foods that are calorie dense.
In terms of implementation of these strategies, one approach would be a consensus from an expert panel on the types of foods to be subjected to these taxes or concessions. This expert panel should include nutrition professionals, academics and clinicians with an interest in obesity. Once a consensus is reached, their recommendations should be presented to administrators and policy-makers for implementation. Evidence-based strategies to decrease energy intake and increase physical activity are now well established. Countries in South-East Asia face an overwhelming burden of NCDs and preventive interventions must be implemented as a matter of urgency.
Source of Support: Nil.
Conflict of Interest: None declared.
Authorship: Both authors contributed equally to the preparation of this manuscript.
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[Table 1], [Table 2]