Scottish Health Survey 2015 - volume 1: main report

Findings and trends of the Scottish Health Survey 2015, providing information on the health of people living in Scotland.


6 Diet

Ian Montagu

Summary

  • Around one in five adults (21%) met the 5-a-day recommendations on the previous day, while 11% did not consume any fruit or vegetables. These levels have changed little since 2003.
  • Adults consumed a mean of 3.1 portions of fruit and vegetables a day in 2015 (3.3 for women compared with 3.0 for men), similar to those seen in 2003.
  • Mean consumption of fruit and vegetables was lowest for those aged 16-24 (2.6 portions) and highest for those aged 55-74 (3.4 portions).
  • In 2015, 12% of children aged 2-15 met the 5-a-day fruit and vegetables recommendations on the previous day.
  • The proportion of children consuming no fruit and vegetables on the previous day in 2015 (7%) was significantly lower than that in 2012 (11%) and 2013 (10%).
  • There were no significant differences by age or sex in the proportion of children meeting the 5-a-day recommendations.
  • In total, 43% of children whose parents ate no fruit and vegetables on the previous day also ate none themselves, compared with 2% of children whose parents met the 5-a-day recommendations.
  • Mean levels of sodium, potassium and creatinine found in spot urine samples were all higher for men than for women in 2014/2015, although mean Na/Cre and K/Cre ratios were higher for women.
  • Mean levels of urinary sodium and creatinine both decreased with age, while mean K/Cre ratios increased with age.
  • In 2015, 27% of adults and 19% of children consumed vitamin or mineral supplements, including 14% of adults and 16% of children who took supplements containing vitamin D.
  • More women than men took supplements; 30% of women and 24% of men took any supplement, and 16% of women and 12% of men took vitamin D.
  • Supplement use was highest among older adults (33-34% of those aged 65 or over), while consumption of vitamin D was highest among those aged 4-5 (25%).

6.1 Introduction

An individual's diet is one of the contributory factors to health over which they have a degree of control. The risk of many non-communicable diseases, including cardiovascular disease, type 2 diabetes and certain types of cancer is affected by the foods people consume. Estimates from international comparisons have suggested that around 30% of cases of cancer [1] and cardiovascular disease [2] worldwide could be prevented by changes in diet, both through improvements in nutritional content and reductions in body mass [3] .

Early research on diet and chronic diseases focussed on the possible role of fat, particularly saturated fat, and fruit and vegetable intake. Some recent studies have questioned the consideration of fruit and vegetables together, and have shown, for example, that vegetable consumption is more important than fruit consumption in explaining reduced risks of certain types of breast cancer [4] , stroke [5] , and diabetes [6] , while reduced risk of coronary heart disease in women [5] , and oesophagal and stomach cancers [7] are better explained by levels of fruit consumption.

Other aspects of diet, including the potentially positive effects of fibre and wholegrains [8] , oily fish intake [9,10] and antioxidant vitamins [11] have been studied in relation to cardiovascular disease and cognitive decline in later life. Folates have been shown to have a role in the prevention of neural tube defects [12] ; vitamin D and calcium are determinants of bone health [13] ; sugar intake is associated wtih dental decay [14] ; and salt intake is linked to the development of hypertension [15] . A link between consumption of red and processed meats in bowel disease has been proposed [16,17] , while it has been suggested that free sugars may have a particular role in the development of obesity and type 2 diabetes [18] .

Given the broad range of health conditions which may be influenced by diet it is difficult to estimate the economic and social costs of poor eating habits, but some examples can highlight the potential benefits of improving the diet of the population. Treatment of cardiovascular disease, including hypertension, and type 2 diabetes, represent significant costs to the NHS, as do treatment of dental decay in children and bone disease in adults. One study looking at the economic costs of risk factors for chronic disease puts poor diet as the largest burden on the NHS, ahead of overweight and obesity, smoking, alcohol consumption, and physical inactivity [19] .

Surveys of household food intake and of children's diet in Scotland have highlighted socio-economic inequalities in consumption of a wide range of food groups such as fruit and vegetables and soft drinks, though differences in fat and sugar content of the diet between those in more versus less deprived areas are not marked [20,21,22] .

6.1.1 Policy background

The most widely promoted diet and health message has been the World Health Organisation ( WHO) '5-a-day' advice for adults to consume at least five varied 80g portions of fruit and vegetables per day. In Scotland the poor record on diet was first highlighted in 1993 with the publication of the Scottish Diet report and associated Action Plan [23,24] . The Action Plan included specific Scottish Dietary Targets for eight nutrients and food groups which would constitute a balanced diet. These were replaced in 2013 by the Scottish Dietary Goals [25] and revised again in 2016 [26] . Goals include the 5-a-day recommendation and a target to reduce salt intake from around 9g to 6g per day for adults. There is a goal in place to reduce average calorie intake by 120 kcal per day and average intake of red meat to 70g per day as well as advice to limit fat and sugar intake and increase consumption of fibre and oil-rich fish. In 2016 new recommendations were introduced to reduce the average intake of free sugars to 5% of total dietary energy. Intakes of dietary fibre should be increased to 30g/day for adults and intakes of starchy carbohydrates should remain at 50% of total dietary energy. A soft drinks industry levy [27] was proposed in the UK Government's 2016 Budget, to be paid by producers and importers of soft drinks across the UK that contain added sugar. Consultation on this is planned in 2016. In addition, existing UK healthy eating advice was updated as the Eatwell Guide to illustrate the proportions and types of foods from major food groups which would make up a healthy diet [28] .

Following recommendations from the Scientific Advisory Committee on Nutrition ( SACN), Scottish Government advice on vitamin D for all age groups has been updated [29] .

To tackle the poor diet of children in Scotland, the main target has been food in schools with Healthy Eating in Schools guidance on implementing the Schools Food and Nutrition legislation which prohibits the sale of foods and drinks high in fat, sugar and / or salt in schools [30] . The foods available to children who leave school at lunchtimes have also been considered in the Beyond the School Gate advice to caterers in the vicinity of schools [31] .

The Scottish Government has also developed the Better Eating Better Learning guidance. This has provided refreshed guidance to a range of stakeholders (schools, local authorities, caterers, procurement departments, parents, children and young people) to support them to work in partnership to make further improvements in school food and food education [32] .

Specific measures which could be taken by retailers, manufacturers and caterers which would affect the wider population are outlined in the Scottish Government's Supporting Healthy Choices framework [33] . This is a voluntary framework based on four core principles. These are to:

  • Put the health of children first in food-related decisions
  • Rebalance promotional activities
  • Support consumers and communities
  • Formulate healthier products

The Scottish Government is also funding a number of programmes aimed at encouraging people to make healthier choices in the way they shop, cook and eat, through its Eat Better Feel Better campaign.

A key part of the Health Promoting Health Service is a focus towards the provision of healthier food choices in hospitals. All NHS-run restaurants for staff, visitors and patients now have the Healthyliving Award Plus as a mandatory requirement with all voluntary sector establishments holding the award. The Healthcare Retail Standard is being implemented in 2016-17 to ensure that any retail outlet in healthcare grounds provides a range of food items that are not high in fat, salt and sugar and that only foods which should be consumed more often or in greater amounts, e.g. fruit and vegetables, are promoted [35] .

6.1.2 Reporting on diet in the Scottish Health Survey ( SHeS)

This chapter provides information on fruit and vegetable consumption among adults and children from 2003 to 2015. Urinary sodium, potassium and creatinine in adults are presented as an indicator of trends in salt intake from 2003 to 2014/2015 with analysis by age and sex presented for 2014/2015. Information on vitamin and mineral supplement use by adults and children in 2014/2015 is also provided. Supplementary tables on diet, including analysis by socio-economic classification, household income and area deprivation are also published on the Scottish Health Survey website [36] .

6.2 Methods And Definitions

6.2.1 Measuring fruit and vegetable consumption

The module of questions on fruit and vegetable consumption was designed with the aim of providing sufficient detail to monitor adherence to the 5-a-day recommendation. These questions have been asked of all adults (aged 16 and over) participating in the survey since 2003 and of children aged 2 to 15 since 2008.

To establish the total number of portions consumed in the 24 hours to midnight preceding the interview, the module includes questions on consumption of the following food types: vegetables (fresh, frozen or canned); salads; pulses; vegetables in composites (e.g. vegetable chilli); fruit (fresh, frozen or canned); dried fruit; fruit in composites (e.g. apple pie); and fresh fruit juice. A portion is defined as the conventional 80g of a fruit or vegetable. Since 80g is difficult to visualise, a 'portion' was described using more everyday terms, such as tablespoons, cereal bowls and slices. Examples are given in the questionnaire to aid the recall process, for instance, tablespoons of vegetables, cereal bowls full of salad, pieces of medium sized fruit (e.g. apples) or handfuls of small fruits (e.g. raspberries). In spite of this, there may be some variation between participants' interpretation of a portion. These everyday measures were converted back to 80g portions prior to analysis. The following table shows the definitions of the portion sizes used for each food item included in the survey:

Food item Portion size
Vegetables (fresh, frozen or canned) 3 tablespoons
Pulses (dried) 3 tablespoons
Salad 1 cereal bowlful
Vegetables in composites, such as vegetable chilli 3 tablespoons
Very large fruit, such as melon 1 average slice
Large fruit, such as grapefruit Half a fruit
Medium fruit, such as apples 1 fruit
Small fruit, such as plums 2 fruits
Very small fruit, such as blackberries 2 average handfuls
Dried fruit 1 tablespoon
Fruit in composites, such as stewed fruit in apple pie 3 tablespoons
Frozen fruit/canned fruit 3 tablespoons
Fruit juice 1 small glass (150 ml)

Since the 5-a-day recommendation stresses both volume and variety, the number of portions of fruit juice, pulses and dried fruit is capped so that no more than one portion can contribute to the total number of portions consumed. Interviewers record full or half portions, but nothing smaller.

6.2.2 Child fruit and vegetable consumption by parental fruit and vegetable consumption

Analysis of child fruit and vegetable consumption by parental fruit and vegetable consumption is based on children in the main sample where at least one of their parents was also interviewed (and answered the questions on fruit and vegetables). The data have been re-weighted so that the analysis shows the pattern of association between child and parental consumption, and provides population estimates of the prevalence of child fruit and vegetable consumption in households with different parental consumption patterns. For households with fruit and vegetable data for two parents, the measure of parental consumption was based on whichever parent's consumption was the highest.

6.2.3 Measuring urinary sodium, potassium and creatinine

Sodium (Na) is obtained from the diet in the form of sodium chloride (salt) and potassium (K) from fruits and vegetables. Urinary excretion of sodium and potassium over a 24-hour period reflects the dietary intake over that day in healthy individuals. However, collection of urine over 24-hours is inconvenient and completeness of collection is difficult to achieve. Spot samples (taken at any time of day) are much easier to collect but the concentration of electrolytes is influenced by hydration. Creatinine (Cre), a non-enzymic breakdown product of creatine in muscle, is produced and excreted in the urine at a constant rate, so the ratio Na/Cre or K/Cre are considered more robust indices for comparative purposes than sodium or potassium concentrations alone.

High levels of sodium in a urine sample may be indicative of a high salt diet, but may also indicate health problems, including kidney problems. Low levels may also be due to kidney damage, as well as a number of other health problems. Abnormal levels of potassium or creatinine may also indicate kidney or other health problems, as well as dietary intake of potassium in fruit and vegetables and creatine from meat or supplements.

Although the concentration of sodium and potassium in spot urine samples cannot be used to estimate 24-hour excretion and hence intake, the values can provide an indication of differences between subgroups within a population and of trends over time.

Reference ranges for each of the analytes in millimoles per litre (mmol/l) are provided by the laboratories and shown in Table 6A below. These are the range of values that would be expected to be seen in 95% of healthy people.

Table 6A Reference ranges for urinary sodium, potassium and creatinine

Men Women
Sodium (Na) 27 - 167 mmol/l 27 - 167 mmol/l
Potassium (K) 17 - 83 mmol/l 17 - 83 mmol/l
Creatinine (Cre) 6.0 - 11.8 mmol/l 4.7 - 10.6 mmol/l

These ranges are based on 24-hour excretion. Higher or lower concentrations in the spot urine samples do not necessarily mean abnormal functioning of the kidneys or high or low levels of salt or meat intake, as they will be influenced by levels of hydration and other factors.

Further information about the collection and analysis of urine samples is provided in volume 2 of this report.

6.2.4 Measuring vitamin and mineral supplement use

The following question, designed to measure self-administered supplement use, is included in the core interview, for all adults and children from 2015:

At present, are you taking any vitamins, fish oils, iron supplements, calcium, other minerals or anything else to supplement your diet or improve your health, other than those prescribed by your doctor?

For those who answered positively, this was followed by a new question:

Are you currently taking vitamin D supplements, including as part of a multi-vitamin supplement?

Women aged between 16 and 49 were also asked about their use of folic acid with the question:

At present, are you taking any folic acid supplements such as Solgar folic acid, Pregnacare tablets, Sanatogen Pronatal, or Healthy Start, to supplement your diet or improve your health?

6.3 Fruit And Vegetable Consumption

6.3.1 Trends in adult fruit and vegetable consumption since 2003

In 2015, adults consumed a mean of 3.1 portions of fruit and vegetables per day (median 2.7). These figures were identical to those measured in 2003. Mean and median fruit and vegetable consumption among adults have fluctuated by small amounts across this period (mean 3.1-3.3, median 2.7-3.0).

Just over a fifth (21%) of adults in 2015 met the 5-a-day recommendations on the previous day. This was a significant decrease from a peak of 23% in 2009, but at the same level as in 2003. The proportion of adults eating no fruit and vegetables on the previous day was 11% in 2015, having been at 9-10% in the previous survey years.

Mean fruit and vegetable consumption among women in 2015 was 3.3 portions, whilst among men mean consumption was significantly lower at 3.0 portions. In each year since 2003 the mean level of fruit and vegetable consumption among women has been measured at between 0.1 and 0.3 portions higher than among men.

The proportion of women eating at least the recommended five portions of fruit and vegetables on the previous day in 2015 was 22% (between 20% and 25% in the years 2003 to 2014). The proportion of men meeting the 5-a-day guidelines on the previous day was 19% (between 19% and 22% in the earlier years of the survey). The difference between men (19%) and women (22%) meeting the guideline was not significant. In 2015, significantly more men (13%) than women (9%) ate no fruit and vegetables on the previous day.

Table 6.1

6.3.2 Adult fruit and vegetable consumption in 2015, by age and sex

Figure 6A shows the relationship between the consumption of fruit and vegetables among adults and age in 2015. Mean daily fruit and vegetable consumption was highest among those aged 55-74 (3.4 portions) and lowest for those aged 16-24 (2.6 portions), the same broad pattern as seen in each survey year since 2003.

In 2015, 15% of those aged 16-24 met the recommended 5-a-day guidelines on the previous day, with this rising to 25% among those aged 55-74. Those aged 16-24 were most likely not to have eaten fruit or vegetables (18%) on the previous day, with this declining with age to 6% among those aged 75 and over.

The proportion of men not having eaten any fruit or vegetables on the previous day was highest for those aged 16-24 (22%) and lowest for those aged 75 and over (7%), with the proportion meeting the 5-a-day guideline increasing with age (from 13% among those aged 16-24 to 25% for those aged 75 and over). For women, the proportion not having eaten any fruit or vegetables on the previous day was highest for those aged 16-24 (15%) and lowest for those aged 65 and over (5-6%). The proportion of women meeting the guideline was lower for those aged 16-24 (16%) and 75 and over (15%) than those aged 25-74 (21-28%).

Figure 6A, Table 6.2

Figure 6A Percentage of adults (16+) eating 5+ portions of fruit and vegetables, no portions, and mean number of portions consumed per day, 2015, by age

6.3.3 Trends in child fruit and vegetable consumption since 2003

Table 6.3 shows trends in fruit and vegetable consumption among children aged 5-15 since 2003, and among children aged 2-15 since 2008. Due to similarities between the mean level of fruit and vegetable consumption among those aged 2-15 and those aged 5-15 (a difference of only 0-0.1 mean portions each survey year), the following paragraphs focus exclusively on figures for the 2-15 age group. Figures for children aged 5-15 indicate no real difference in fruit and vegetable consumption between 2003 and 2008.

In 2015, mean fruit and vegetable consumption among children aged 2-15 was 2.7 portions. There has been little change in the level of consumption of fruit and vegetables among this age group over time, with mean consumption measured at between 2.6 and 2.8 portions in each survey year since 2008.

From 2008 to 2015, mean fruit and vegetable consumption has fluctuated between 2.7 and 2.9 portions for girls aged 2-15, and between 2.5 and 2.7 portions for boys aged 2-15. In 2015, girls consumed 2.8 mean portions and boys consumed 2.7.

The proportion of those aged 2-15 meeting the recommended 5-a-day guideline on the previous day in 2015 was 12%. As with mean fruit and vegetable consumption among this age group, this figure has fluctuated only by small amounts since 2008 (12-15%).

The proportion of those aged 2-15 eating no fruit or vegetables on the previous day was 7% in 2015, a significant decrease on levels seen in 2012 (11%) and 2013 (10%).

Table 6.3

6.3.4 Child fruit and vegetable consumption in 2015, by age and sex

There was no difference in the proportion of children eating their recommended 5 portions of fruit and vegetables on the previous day by either by age group (fluctuating between 8 and 14%) or sex (12% among boys and 13% among girls). The proportion of those aged 2-4 consuming no fruit and vegetables on the previous day was 3%, rising with age to 12% of those aged 13-15. Boys (9%) were significantly more likely to have eaten no fruit and vegetables than girls (5%). Eating no fruit and vegetables tended to increase with age for both boys (4% for those aged 2-4 to 16% for those aged 13-15) and girls (2% for those aged 2-4 to 8-9% for those aged 11-15).

Figure 6B, Table 6.4

Figure 6B Percentage of children (2-15) eating 5+ portions of fruit and vegetables and no fruit and vegetables per day, 2015, by age

6.3.5 Child fruit and vegetable consumption in 2012-2015 (combined), by parental fruit and vegetable consumption

Figure 6C shows the relationship between the consumption of fruit and vegetables by children aged 2-15 and that of their parents in 2012-2015. The mean number of portions consumed by children increased in line with parental consumption from 1.0 portions per day among those whose parents consumed no fruit and vegetables on the previous day to 3.7 portions for those whose parents consumed the recommended daily five or more portions. A similar pattern was seen both for boys (from 1.0 to 3.4 mean portions) and for girls (from 1.0 to 3.9 mean portions).

In 2012-2015, 43% of children aged 2-15 whose parents consumed no fruit and vegetables on the previous day also consumed no fruit and vegetables themselves, compared with 2% of those whose parents consumed the recommended five or more portions. Conversely, 22% of those whose parents did consume the recommended five or more portions met the 5‑a-day guideline compared with 1% of those whose parents did not consume any fruit and vegetables.

Figure 6C, Table 6.5

Figure 6C Percentage of children (2-15) eating 5+ portions of fruit and vegetables, no portions, and mean number of portions consumed per day, 2015, by parental consumption

6.4 Urinary Sodium, Potassium And Creatinine In Adults

6.4.1 Trends in urinary sodium, potassium and creatinine in adults, since 2010/2011 (combined)

Table 6.6 shows mean urinary sodium (Na), potassium (K) and creatinine (Cre) levels among adults aged 16 and over for survey years 2003, 2008/2009, 2010/2011, 2012/2013 and 2014/2015, measured using spot urine samples. Median levels and levels for the 5th, 10th, 90th and 95th percentiles, are also presented.

Some caution should be applied in the interpretation of these trends, given the changes in assay methods for all three analytes in 2010 (see volume 2 of this report). The following paragraphs therefore cover the period from 2010/2011 to 2014/2015.

In 2014/2015 the mean urinary level of sodium in adults was 100.5mmol/l, with it being significantly higher for men (109.2mmol/l) than for women (92.5mmol/l). Mean sodium levels for all adults have not changed significantly since 2010/2011, although there has been a significant decrease for men since that date, when the mean urinary level of sodium stood at 117.6 mmol/l. Median sodium levels for men and levels at the 10 th and the 90 th percentiles also followed this pattern of decline.

Mean urinary potassium levels were also higher for men (59.3 mmol/l) than women (54.6 mmol/l) in 2014/2015. These levels were similar to those observed in 2010/2011. The level for all adults in 2014/2015 was 56.9 mmol/l.

Similarly, mean urinary levels of creatinine were also higher for men (11.4 mmol/l) than women (8.6 mmol/l) in 2014/2015, with no significant change since 2010/2011. The level for all adults in 2014/2015 was 9.9 mmol/l.

As noted in section 6.2.3, the sodium / creatinine and the potassium / creatinine ratios are considered better indices for comparative purposes than sodium or potassium concentrations alone. These have both remained fairly constant between 2010/2011 and 2014/2015 for men and women alike. Mean levels were, however, significantly higher on both measures in 2014/2015 for women (mean Na/Cre ratio 14.2, mean K/Cre ratio 7.7) than men (mean Na/Cre ratio 11.9, mean K/Cre 6.1).

Table 6.6

6.4.2 Urinary sodium and potassium in adults in 2014/2015 (combined), by age and sex

Table 6.7 presents levels of urinary sodium, potassium and creatinine levels for adults in 2014/2015 by age and sex.

Sodium levels among adults in 2014/2015 declined with age. Among those aged 16-44, the mean urinary level of sodium stood at 111.5 mmol/l in 2014/2015, with lower levels for those aged 45-64 (96.0 mmol/l) and those aged 65 and over (84.8 mmol/l).

Mean urinary sodium levels among men were higher than those among women in every age group, albeit with less of a difference between men and women aged 16-44 (117.6 mmol/l for men compared with 105.6 mmol/l for women) than those aged 65 and over (96.0 and 75.9 mmol/l respectively).

Levels of potassium did not vary significantly with age in 2014/2015, with levels for those aged 16-44, 45-64 and 65 and over at 57.8, 57.2 and 54.4 mmol/l respectively.

As with levels of sodium, creatinine levels decreased with age, from 11.1 mmol/l among those aged 16-44 to 9.3 mmol/l among those aged 45-64 and 8.5 mmol/l among those aged 65 and over.

In line with the decreases with age in both mean urinary sodium levels and mean urinary creatinine levels, the mean Na/Cre ratio did not vary significantly with age (between 12.6 and 14.4 for the three age groups).

The mean K/Cre ratio did increase significantly with age, from 6.2 for those aged 16-44 to 7.7 for those aged 65 and over. This pattern held for both men (5.5 to 6.8 respectively) and women (6.8 to 8.5 respectively).

Table 6.7

6.5 Consumption Of Vitamin And Mineral Supplements

6.5.1 Adult consumption of vitamin and mineral supplements in 2015, by age and sex

Figure 6D shows the 2015 levels of consumption of vitamin or mineral supplements among adults aged 16 and over by age and sex. In 2015, 27% of adults consumed vitamin or mineral supplements, including 14% who consumed a supplement containing vitamin D.

The level of vitamin or mineral supplement consumption differed significantly between men and women in 2015, with 30% of women consuming supplements compared with 24% of men. Women were also significantly more likely than men to take supplements containing vitamin D (16% compared with 12%).

In 2015, among women, supplement consumption was highest in the 65 and over age group (35-37%). Among men, supplement consumption was highest for those aged 25-34 and those aged 75 and over (both 31%). For both men and women, supplement consumption was lowest among those aged 16-24 (16% of men and 25% of women).

Figure 6D, Table 6.8

Figure 6D Percentage of adults (16+) consuming vitamin or mineral supplements, 2015, by age and sex

Consumption of supplements containing vitamin D in 2015 was highest for those aged 25-34 (20%) and lowest for those aged 45-54 (10%), with a similar pattern being seen for both men and women.

Supplements containing folic acid were being used by 6% of women aged 16-49 at the time of the survey. Such supplements were being used by 2% of women aged 16-24,10% of those aged 25-34, 8% aged 35-44, and 3% aged 45-49.

Table 6.8

6.5.2 Child consumption of vitamin and mineral supplements in 2015, by age and sex

In 2015, 19% of children aged 0-15 consumed vitamin or mineral supplements, including 16% who consumed a supplement containing vitamin D. There were no significant differences for boys and girls either for total vitamin supplementation (19% for both boys and girls) or vitamin D consumption (15% for boys and 16% for girls).

Consumption of vitamins and minerals by children did vary with age. The highest levels of consumption were seen among those aged 4 and 5 (27% were taking any supplements, including 25% who consumed a supplement containing vitamin D). The lowest levels were seen among those aged 12 to 15 (10-11% taking any supplements and 7-8% taking a supplement containing vitamin D).

Figure 6E, Table 6.9

Contact

Email: Julie Landsberg, julie.landsberg@gov.scot

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