Guidelines For Healthy Nutrition

Guidelines For Healthy Nutrition

Decades of research that has considered the relationships between diet and disease have left no doubt that defining the optimal diet for a population is a complex process and that communicating dietary advice clearly to the population is a major challenge. Individuals respond metabolically to variation in the composition of the diet in different ways, and this variation will depend upon often poorly understood genetic factors, early life programming influences, the microbiome and lifestyle factors. However, it is clear that in general terms a healthier diet should be a varied diet in which carbohydrate provides the basic staple, with energy intakes from fat and protein providing lesser components of intake (Table 8.1). In most circumstances, healthy adults are advised to base meals on starchy foods, to consume five portions of fruit and vegetables per day, to consume two portions of fish per week (including one of oily fish) and to have low intakes of fats and sugars. Food intakes should be well spaced throughout the day, and breakfast remains an essential meal of the day, as in childhood and USP.

Table 8.1 General guidelines for intake of sugars, fats and salt by adults.

Source: Department of Health (1999).

Guidelines For Healthy Nutrition

Nutrient                       Maximum recommended intake (% of daily energy)


Saturated fatty acids          10

Polyunsaturated fatty acids    10

* Also referred to as population averages.

† Also referred to as free sugars.

Engagement of the public with healthy eating messages is variable and understanding is often poor. To a large extent, this results from the way in which the media portrays nutritional science. The reporting of studies of nutrition, health and disease is often overly simplistic and selective and fails to cover the limitations of studies. Reporting rarely describes an overview of a large body of evidence and instead represents single, isolated studies. Mixed messages and inappropriate reporting can induce scepticism and resentment, leading to rejection of established healthy eating guidelines by the public. For example, a report by Oyebode et al. (2014) demonstrating that consumption of seven or more portions of fruit and vegetables per day reduced all‐cause mortality in the Health Survey for England prompted media reporting that existing guidelines should change and tabloid pronouncements about ‘food police’ and unreasonable demands for dietary change. However, the original paper had done no more than confirm well‐established observations. Similarly, reporting of a meta‐analysis on fats and CVD (Chowdhury et al., 2014) concluded that there was little evidence to back up current advice to replace saturated fats with polyunsaturated fats prompted a media outcry about the merits of butter and further public misunderstanding of science. The media highlights and thrives upon disagreement and controversy, and as a result, the public struggle to understand how scientific evidence accumulates slowly, how the nature of our understanding tends to be provisional, and that the overall balance of data are more important than single studies. UK reporting of a call from Action on Sugar (2014) for aggressive action to reduce sugar consumption suggested to the public that single nutrients or classes of nutrients were drivers of disease, which, as described later in this chapter, is a viewpoint that most nutritional scientists

would now reject and recognize as a mistake in early research into diet and cancer. This view was reinforced by changes to population guidelines to state that intakes of free sugars should be no more than 5% of energy intake

(Scientific Advisory Committee on Nutrition, 2015). The growth of social media as an influencer of beliefs and behaviour is increasingly problematic. Prominent social media figures can promote dietary extremes to suit a particular agenda

(usually a new diet book and personal profit), deride expert advice and condemn nutrition professionals as ‘shills’ for the food industry, without the need to fact check. Observing unqualified, self‐styled nutrition gurus declaring that low‐carbohydrate, high‐fat diets are an ideal and that the dietary advice that has stood in place for more than 40 years is ‘genocide’ (Alliance for Natural Health, 2019), is difficult and hurtful for the dedicated professionals who have made public health and dietetic care their careers.

Despite these contradictions in the media and associated confusion among consumers, highly successful health promotion campaigns across westernized countries, such as the five‐a‐day campaign (NHS England, 2018), mean that many general messages about healthy nutrition are now widely recognized, but are not necessarily fully understood or adhered to. Communicating information such as that shown in Table 8.1 to the population presents a sizeable problem. Concepts such as percentage of daily energy intake are complex and mean nothing within the context of individuals’ daily dietary choices. Even with successful campaigns such as five‐a‐day, understanding of the detail behind the generalized message is often weak. The need to consume five portions of fruit and vegetables per day is simple to remember, but defining a ‘portion’ (actually 80 g of fresh, frozen, canned or dried fruit, vegetables, salad, fruit juice) is beyond most people. As a result, most governments in westernized nations have sought to develop simple pictorial models to act as a guide to healthy adults, showing what comprises a healthy and well‐balanced diet. In the UK, the Balance of Good Health plate model was introduced in the mid‐1990s for this purpose (Health Education Authority, 1995). The Food Standards Agency redesigned this model in 2007 and Public Health England refined it again in 2016, producing the new Eatwell Guide (Figure 8.2).

Figure 8.2 The Eatwell plate. This pictorial representation of the relative proportions of foods from each of five groups that should be included in a healthy diet is used as one of the key aids in health education in the United Kingdom.

Source: Public Health England (2016).

The Eatwell Guide works on a principle that is common to similar models that are used in other countries, for example, the US Food Pyramid (US Department of Agriculture, 2005). Foods are divided into food groups. Within the Eatwell model, there are fruits and vegetables, breads, cereals and potatoes, milk and dairy, meat, fish and alternatives and foods containing fat and sugar. The sectors on the plate (Figure 8.2) are supposed to reflect the relative amount of food intake that should come from each group; hence, breads, cereals and potatoes, fruits and vegetables should provide approximately two thirds of intake. The most recent iteration of the Eatwell Guide removed foods rich in free sugars completely and confined oils and spreads to a very small component, to emphasise the message that fats and sugars should be consumed at a minimal level. There are variations on this model (e.g. Japanese Spinning Top Food Guide, Swedish Food Circle), and within the US Food Pyramid, for example,

fruits and vegetables are in their own separate food groups, and it is suggested that intakes of foods from the breads, cereals, pasta and rice group outweigh intakes of the fruit and vegetable groups. The Swedish Food Circle is similar in design to the Eatwell plate but crucially lacks the foods containing fat and sugar food group (hence discouraging their intake altogether) and separates vegetables into ‘root vegetables’ (starchy roots such as carrots and potatoes) and ‘essential vegetables’ (green leafy vegetables that are important micronutrient sources). The US Food Pyramid was first introduced in 1992 and was widely taken up by other countries in Europe, Australasia, Africa and Asia. An updated version of the pyramid model, MyPyramid, was introduced in the United States in 2005 to reflect some of the factors, including age, weight and ethnicity, that shape nutrient demands. In 2011, the US Department of Agriculture replaced the Food Pyramid with ‘MyPlate’, which recommends targets for food group consumption with detail on what and how much to eat within a daily energy allowance based on age, sex, body mass index (BMI) and level of physical activity. This provides a more personalized format for nutrition advice but required positive engagement with users who need to input their own health data. This latter point emphasizes the major problem with all such pictorial guidance schemes, as they can educate, but are of little practical use to individuals in daily life.

When confronted with the infinite variety of food products in supermarkets, individuals either forget or become confused by healthy eating messages. This has prompted many countries to promote improved food labelling schemes that provide clear and simple nutritional messages at the point of sale. In the UK, attempts to introduce a food ‘traffic light’ scheme in which foodstuffs would bear a label showing content of fat, saturated fat, sugar and salt highlighted as red for high, amber for medium and green for low has largely failed due to lack of commitment from supermarkets. It is now common practice for foods to be labelled with the less informative ‘guideline daily amounts’ (Figure 8.3). Consumers in Norway, Sweden, Iceland and Denmark have a simplified guide to healthy options when buying food in shops or eating out. The Livsmedelsverket Keyhole (Figure 8.3) symbol is a voluntary label, and food producers take responsibility for ensuring that foods bearing the symbol conform to regulations and are low in fat, sugar and salt and high in dietary fibre.

Guidelines For Healthy Nutrition

Figure 8.3 Symbols used in food labelling. a) A guideline daily amount‐based food label. Guideline daily amounts on food labels represent the average requirements of an adult woman. Presenting front‐of‐pack information on energy, sugar, fats and salt is intended to enable consumers to make healthy choices. b) The Swedish National Food Administration Keyhole symbol. Only foods that are low in fat, sugar and salt can carry this logo, which allows consumers to identify the foods that comprise a healthy diet, both in shops and when eating out.

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