NDNS: time trend and income analyses for Years 1 to 9

The National Diet and Nutrition Survey – Years 1-9 of the rolling programme (2008/9 – 2016-17)

Time trend and income analysis

This report out today from Public Health England and the Food Standards Agency looks at trends over the course of the 9 years of the rolling programme in terms of food consumption, nutrient intakes and nutritional status in the UK.

They also looked at these outcomes by household income for years 5-9 (2012/13 -2016/17).

The findings highlight both positive and negative changes to the nation’s diet over this time period. The change are described in percentage points representing the numerical difference between percentages over 9 years, and intakes assessed against government recommendations.

Time trends over 9 years 2008/9 to 2016/17

Intakes of free sugars and sugary drinks down, but intakes remain well above maximum recommendation

The biggest changes to both free sugars and sugary drinks were seen in children. Free sugars intakes (as a percentage of total energy) reduced by between 2.7 and 3.5 percentage points across the 9 year period. There were reductions in both the percentage of children who consumed sugar-sweetened soft drinks  (between 17 and 35 percentage points reduced) and the quantities consumed by those who drank them (an average yearly reduction between 3-6%).

For adults, these downward trends were also seen but the reductions were smaller and were not always significant.

No significant change to total fruit and veg intakes or the proportion meeting the 5 A DAY recommendation

Overall there was little change to total fruit and vegetable intakes and the proportion of people meeting the 5 A DAY target remains low at about 30% for adults and around 10% for 11-18 year olds. Intakes of fruit juice decreased across the population but this was only statistically significant in some groups; over the 9 years  this was  estimated as a reduction of 54g/day (children aged 4-10 years (6g average yearly reduction) , 48g/day in girls aged 11-18 years (5g average yearly reduction) and 32g/day in women aged 19-64(4g average yearly reduction).

Generally little change in oily fish consumption to fish intakes

There were no or very small changes to either the proportion of people consuming fish or the amounts consumed, both for oily and for total fish consumption. There was a statistically significant 1 percentage point per year increase in consumption of oily fish for children aged 11-18 year old (increase by 10 percentage points between 2008/9 and 2016/17, but mean consumption remained well below recommended limits  in all age groups.

Reductions in red and processed meat intakes

There were small reductions in red and processed meat intakes across the population although these were not always significant. The greatest yearly reductions of 3g/d were seen in boys aged 11-18 years. For all children aged 11-18 years over the nine year period there was a decline of 15g. Mean consumption of red and processed meat in adult men remained greater than 70g per day.

There were no significant changes to white meat consumption in terms of the percentages consuming white meat, or in the intake of white meat by consumers.

Little change to energy and fat intakes

There was an average decrease in total energy (calorie) intakes across the population although this was not always significant. The largest changes seen were in girls aged 4-10 years (average yearly reduction -24kcal/day) and in boys 11-18 years (average yearly reduction -29kcal/day). For other groups the decrease was less than about 12kcal per day. It’s worth noting that there may be some issues with under-reporting of energy in dietary surveys and that levels of obesity in children aged 10-11 years have continued to increase according to the latest National Child Measurement programme.

There were no consistent patterns in total or saturated fat intakes with the recommendation for total fat providing about 35% of food energy generally being met but with intakes of saturated fat remaining above recommended levels. Intakes of trans fatty acids as a percentage of food energy, which were already below the recommended levels in all groups, were significantly reduced.

Small changes to dietary fibre intakes

There were small reductions in children’s fibre intakes, which were only significant for girls aged 4-10 (0.2g/day per year) and small but significant increases in fibre intakes for adult men (0.3g/d per year). In other groups there were no significant changes to fibre intakes, and on average all intakes remain well below the recommended intake

Downward trends in in proportion consuming alcohol but not amount consumed

There was a downward trend in the percentage of people consuming alcohol for all groups aged 11 and over and this was statistically significant for adults aged 19-64 years (-2% per year) and for girls aged 11-18 years (-1% per year). For adults there was no decrease in the quantity of alcohol consumed by those who drank alcohol and for 11-18 year olds there was a small decrease (-0.3% per year).

Reductions in micronutrient intakes

For a number of micronutrients including vitamin A, riboflavin, folate, iron, calcium, iodine, potassium and zinc, reductions in intakes and an increase in the proportion of people with low intakes (below the lower reference nutrient intake) were seen.  This is a potential concern although it is highlighted in the report that the NDNS captures 4 days of participants’ intake and that this does not necessarily represent sustained low intakes that could lead to negative outcomes. However, as these are essential nutrients for health the possible causes and effects of this finding may warrant further investigation.

Blood folate concentrations decreased significantly over the 9 year period and the proportion of participants with blood folate levels indicating risk of anaemia increased. There was also an increase in the proportion of women of childbearing age (16-49 years) with a red blood cell folate concentration below the threshold for an increased risk of a pregnancy being affected by a neural tube defect from around two thirds to almost 90% over the 90 years surveyed. There was little change to the status of other nutrients where status was measured; riboflavin, vitamins B12, C and D, iron or to lipid profiles.

Concerns with vitamin D status

Average blood vitamin D measures (25-hydroxy vitamin D (25-OHD)) were lowest from January to March when 19% of children aged 4-10 years, 37% of children aged 11-18 years and 29% of adults had levels below the threshold that indicates risk of deficiency (25nmol/L 25-OHD).

Diet and household income (analysis of year 5 to 9 (2012/13 - 2016/17).

The report looked at the effect of each £10,000 of household income on diet and found that with increasing income there was:

• Greater fruit and vegetable intake (except in men aged 65 years and older).
• Lower percentage consumption of sugar-sweetened drinks, higher percentage consumption of fruit juice.
• Small but significantly lower intakes of free sugars in adults; decreasing trend (not statistically different) for children aged 11-18 years and older adults (aged over 65). For younger children (< 11 years) there was no change in free sugars intake with increasing income.
• Higher intakes of fibre, vitamin A and folate.
• Higher intakes of total fat (although not in children, and decreased with income for children aged 1.5-3 years).
• Higher intakes of saturated fat (although changes were small and not always significant).
• Higher intakes of sodium for adults.
• A trend for better nutritional status for micronutrients e.g.
  • No statistically significant trend for haemoglobin (an indicator of risk of anaemia), but ferritin (a measure of the body’s iron stores) tends to increase particularly in adult men aged 19 years and over
  • Significant increase in red blood cell folate and serum folate in most age/sex groups; greatest for men aged 65 years and over;
  • Increases in vitamin C in some children (not children 1.5 -3 and boys 4-10 years) and most adult age/sex groups.

Overall, some positive news on sugar but plenty of room for improvement to UK diets

While the decreases in free sugars intakes and consumption of sugary drinks are welcome there is still much that could be improved in the UK diet according to these figures, including the need to increase fruit and vegetable intakes, increase consumption of fish and dietary fibre and reduce our intakes of saturated fat. The report indicates that those on lower incomes may be more at risk of having a poorer quality diet although this was not the case for all outcomes.

For more information about dietary requirements click here