Healthy and Sustainable Food Systems

Mark Lawrence, Sharon Friel, Mark Lawrence, Sharon Friel

• Editorial: Routledge
• Año: 2019
• ISBN:
  9781351189019
• Edición: 1
• Categoría: Médecine
• Categoría: Prestation de soins de santé

This comprehensive text provides the latest research on key concepts, principles and practices for promoting healthy and sustainable food systems.

There are increasing concerns about the impact of food systems on environmental sustainability and, in turn, the impact of environmental sustainability on the capacity of food systems to protect food and nutrition security into the future. The contributors to this book are leading researchers in the causes of and solutions to these challenges. As international experts in their fields, they provide in-depth analyses of the issues and evidence-informed recommendations for future policies and practices. Starting with an overview of ideas about health, sustainability and equity in relation to food systems, Healthy and Sustainable Food Systems examines what constitutes a food system, with chapters on production, manufacturing, distribution and retail, among others. The text explores health and sustainable diets, looking at issues such as overconsumption and waste. The book ends with discussions about the politics, policy, personal behaviours and advocacy behind creating healthy and sustainable food systems.

With a food systems approach to health and sustainability identified as a priority area for public health, this text introduces core knowledge for students, academics, practitioners and policy-makers from a range of disciplines including food and nutrition sciences, dietetics, public health, public policy, medicine, health science and environmental science.

PART I

Overarching dimensions of healthy and sustainable food systems

1

HEALTH

Corinna Hawkes and Jessica Fanzo

Introduction

Every human being has the right to adequate, nutritious food. The realisation of this right around the world will not be achieved without food systems that ensure optimal nutrition for everyone, now and into the future. Food systems are meant to provide food that is healthy, of sufficient quality and quantity, affordable, safe and culturally acceptable. However, something has gone wrong, and what we are left with is a high burden of malnutrition in all its forms (undernutrition, micronutrient deficiencies, overweight and obesity) which affects every country on the planet.

With urbanisation and globalisation, economic growth, and food industry consolidation, the length of the food supply chains has increased, and food environments have become more complex. Bold policies, initiatives and investments are needed to shape food systems that contribute to improved nutrition and ensure that food is produced, distributed and consumed in a sustainable manner that protects the right to adequate food for all. This chapter provides an overview of the importance of diets and food systems in shaping nutrition.

Malnutrition and ill-health

Malnutrition, in all its forms (Figure 1.1), is to blame for a significant proportion of global ill-health. Child and maternal malnutrition have been identified as the world’s leading cause of human mortality and years of healthy life lost (or disability-adjusted life-years, DALY) with sub-optimal diets, estimated to be the second top risk factor (Gakidou et al., 2017) (Figure 1.2).

FIGURE 1.1 Malnutrition in all its forms

Source: IFPRI (2016).

FIGURE 1.2 Major risk factors for global morbidity and mortality

Source: Gakidou et al. (2017).

Malnutrition affects people’s health by: (1) impacting negatively on physical and cognitive development; (2) compromising the immune and cellular systems; (3) increasing susceptibility to communicable and non-communicable diseases and associated risk factors; and (4) restricting the attainment of human potential and reducing productivity (Black et al., 2008). Young children are particularly susceptible to malnutrition. As of 2017, 151 million children under the age of 5 suffer from stunting – they do not grow tall enough for their age. Wasting affects 51 million children under the age of 5 (UNICEF et al., 2018). Another indicator of poor nutritional status is low birth weight (LBW), defined as live births in a given population and over a given time period that, with birth weight of less than 2.5 kg, places infants at increased risk of morbidity and mortality. Estimates suggest that 20 million newborn babies have LBW (DI, 2018). In addition, it is estimated that 38.3 million children under the age of 5 are overweight (UNICEF et al., 2018).

Micronutrient deficiencies, in particular, Vitamin A, iodine, iron and zinc, affect billions of people. Although the estimates of the true extent of the problem are incomplete, the link between deficiencies and disease is well established (Allen de Benoist, Dary, & Hurrell, 2006). Iodine deficiency is associated with goitre and can compromise mental health, leading to reduced intellectual capacity. Vitamin A deficiency is associated with visual impairment and increased risk of diarrhoeal disease and measles. Deficiencies affect a whole range of further problems for growth and development, including birth defects, growth impairment, reduced cognitive function and greater vulnerability to infectious diseases. Iron deficiency is one cause of anaemia, which is associated with maternal and child mortality, poor physical performance, and chronic kidney and heart disease (Lopez, Cacoub, Macdougall, & Peyrin-Biroulet, 2016). Anaemia prevalence in girls and women aged 15–49 is 32.8 per cent and among pregnant women, 40.1 per cent in 2016 (DI, 2018). Currently, millions of women are too thin; 9.7 per cent of women and 5.7 per cent of adolescent girls are underweight. All forms of women’s undernutrition affect their health (Fox et al., 2018), and if during pregnancy, contributes to foetal growth restriction, in turn, increasing the risk of infant deaths and among those who survive, stunting (Black et al., 2013).

At the same time, a staggering 2 billion adults are overweight, 678 million with obesity. Data on the prevalence of overweight adults (age 18+ years) show an increase from 35.7 per cent in 2010 to 38.9 per cent in 2016. Obesity prevalence in adults also shows an increase from 11.2 per cent in 2010 to 13.1 per cent in 2016. Globally, women have a higher prevalence of both overweight and obesity compared to men (DI, 2018). Obesity is a risk factor for a wide range of non-communicable diseases. Diet-related non-communicable diseases are a leading contributor to this mortality and morbidity, notably heart diseases, diabetes and some cancers. In total, “NCDs were responsible for 41 million of the world’s 57 million deaths (71 per cent) in 2016, of which diet was one of the four leading risk factors” (WHO, 2018). Some 15 million of these deaths were premature (within the ages of 30–70 years). Some 78 per cent of all NCD deaths occur in low- and middle-income countries. Of these, 85 per cent are premature deaths.

Countries experience multiple burdens of these different forms of malnutrition. Data analysed by the 2018 Global Nutrition Report show that 88 per cent of the 141 countries with consistent data on three forms of malnutrition – childhood stunting, anaemia in women of reproductive age and overweight adults – experience a high level of at least two types of malnutrition, with 29 per cent (41 countries) having high levels of all three (DI, 2018). Most of these 41 countries are in Africa. When thinness among women is added, 23 per cent – almost one quarter of countries – have high burdens of four forms of malnutrition.

In individuals, estimates suggest that 1.9 per cent (8.23 million children under the age of 5) experience conditions associated with both deficiency (stunting) and excess (overweight) at the same time (DI, 2018). Almost 4 per cent of under-fives globally are both stunted and wasted – 15.95 million children. While the physiological mechanisms leading to this are not well understood, important evidence indicates that these children are at an elevated risk of mortality comparable to that associated with severe wasting (McDonald et al., 2013). Different forms of malnutrition can overlap in individuals and households (Tzioumis & Adair, 2014). Studies have shown that some households contain both overweight parents and undernourished children. The prevalence of these “double burden” households varies considerably (Tzioumis & Adair, 2014; Wojcicki, 2014). In Asia, for example, the prevalence of double burden households ranges from 5.0 per cent in Vietnam to 30.6 per cent in Indonesia (Rachmi, Li, & Baur 2018).

The link between diets and malnutrition

The burden of ill-health caused by malnutrition is directly linked to the food system because what people eat is a common cause of malnutrition in all its forms. Other factors also matter, including breastfeeding, access to clean water and physical activity. However, eating the right diets to meet nutrient needs is necessary, albeit not sufficient. Diets that promote good nutrition and health outcomes can be termed “healthy diets”. There is no one single diet that promotes good health, but to avoid malnutrition and related health outcomes, a person must meet their needs for essential macronutrients (proteins, fats and carbohydrates, including dietary fibres) and micronutrients (vitamins, minerals and trace elements), which vary with their gender, age, physical activity level and physiological state. Conversely, healthy diets do not include excessive amounts of dietary energy, nor nutrients that have negative health outcomes when consumed in excess, such as trans and saturated fats, added sugars, salt. Available scientific evidence has led to recommendations on the general dietary patterns that promote health (Box 1.1).

BOX 1.1 A HEALTHY DIET

Based on the available scientific evidence on the link between diet, malnutrition and diseases, The World Health Organization (WHO, 2015a) recommend the following as a diet that prevents malnutrition in all its forms and diet-related non-communicable diseases:

• High in fruits, vegetables, legumes (e.g. lentils, beans), nuts and whole grains (e.g. unprocessed maize, millet, oats, brown rice).
• Intake of animal source foods (dairy, meat, eggs, fish and shellfish, etc.) in moderation, and limit processed meats.
• Low intake of refined sugars that are added to foods or drinks by the manufacturer, cook or consumer, and concentrated sugars naturally present in honey, syrups, fruit drinks and fruit juice concentrates.
• Substitute unsaturated fats or vegetable oils (e.g. found in fish, avocado, nuts, sunflower, canola and olive oils) in place of saturated fats (e.g. found in fatty meat, butter, palm and coconut oil, cream, ghee and lard). Industrial trans fats, or partially hydrogenated oils (found in processed food, fast food, snack food, fried food, baked goods, margarines and spreads), are not part of a healthy diet.

Whatever form they take, to promote health, diets must be sufficient and balanced in terms of quantity, quality and safety, each of which is described below:

Quantity

The first consideration is quantity. For optimal nutrition, diets must be adequate in energy (in the form of calories) to maintain life, support physical activity and maintain a healthy body weight, but without excessive consumption of dietary energy. If dietary energy intake exceeds energy expenditure, overweight and obesity can potentially ensue. Everyone requires different amounts of energy each day, depending on age, sex, size and activity level. When insufficient energy is consumed, hunger ensues. Even temporary periods of hunger can be debilitating to longer- term human growth and development. Acute hunger is when lack of food is short-term and is often caused by shocks, whereas chronic hunger is a constant or recurrent lack of food (Webb et al., 2006). The term undernourishment defines insufficient food intake to continuously meet dietary energy requirements with the Food and Agricultural Organization (FAO) further defining hunger as the consumption of less than 1600–2000 calories per day.

Quality

The second consideration is quality – the types of foods consumed and their diversity. Dietary diversity is a vital element of diet quality – the consumption of a variety of foods across and within food groupings including vegetables, fruits, whole grains and cereals, dairy foods and animal- and plant-based protein foods, while limiting foods and beverages high in saturated and trans fats, added sugars and salt. Fibre, legumes, omega-3 fatty acids, and polyunsaturated fatty acids, are other dietary elements that contribute positively to health. Consuming in this way more or less guarantees an adequate intake of essential nutrients and important non-nutrient factors. Research has demonstrated a strong association between dietary diversity and diet quality, and nutritional status of children and women (Arimond & Ruel, 2004; Jones, 2017). It is also clear that household dietary diversity is a sound predictor of the micronutrient (vitamins and minerals) density of the diet, particularly for young children (Girard, Self, McAuliffe, & Olude, 2012). Consuming inadequate amounts of nutrient-dense foods – particularly fruits, vegetables, whole grains, and nuts and seeds – is a leading contributor to the global burden of disease (see Figure 1.2) (Gakidou et al., 2017).

However, diversity in and of itself is not sufficient if the diet includes too many foods high in fats, sugars and salt, leading to obesity and non-communicable diseases (NCDs). The quality of diets thus also depends on limiting foods and beverages high in saturated and trans fats, added sugars and salt. Diets high in red meat, processed meat (smoked, cured, salted or chemically preserved), sugar-sweetened beverages, trans fats and sodium detract from diet quality and health. Minimally processed whole grains with higher dietary fibre content promote health relative to refined grains (e.g. starchy white breads). There are healthy sources of fats including monounsaturated and polyunsaturated fats that lower risk of NCDs, including olive oil, canola and sunflower oil, as well as fats found in certain foods like seeds and fish. Unhealthy fats are trans fats, made from partially hydrogenated oil and less so but still not with minimal harm, saturated fats found in coconut and palm oils, red meats, butter and cheese (Hu, 2010).

Foods undergo various forms of processing. This includes milling brown rice into white and wholewheat flour into white, pasteurisation and fermentation of milk, cutting up, canning and freezing ve...