Friday February 18 2011
Diet appears to be improving but there is still more to do
Today’s children are a junk food generation facing a “diabetes timebomb” according to The Daily Mail. The newspaper says that research into the modern diet of UK children also shows that many consume just half of their recommended fruit and vegetable intake.
The research brought together published studies, surveys, health guidelines and reports that had addressed the diet of UK children in order to examine dietary changes over the years and the current nutritional issues facing children today. The authors say that while there has been improvement in children’s diet over the years, many still experience dietary deficits, and that there need to be child-specific targets for fibre, long-chain fatty acids, vitamin D, and fruit and vegetable consumption.
While interesting reading, the study does not indicate how the studies were selected, and it is possible that other relevant or conflicting literature has not been considered. A rise in type 2 diabetes in children was only briefly mentioned in the review as the narrative focused on dietary patterns rather than their potential health consequences.
Where did the story come from?
The study was carried out by researchers from Nutrition Communications and Manchester Metropolitan University. No sources of funding were reported. The study was published in the peer-reviewed journal, Nutrition and Food Science.
The body of the Daily Mail’s article discusses the findings of this narrative review, but its headline relating to diabetes is misleading as the condition was only mentioned in passing in this review.
What kind of research was this?
This was a literature review that aimed to discuss published studies and reports that had in some way addressed the diet of children in the UK. It referenced material examining issues such as dietary changes over the years and current dietary issues facing children today. The researchers principally aimed to examine whether children are currently achieving their recommended nutritional intake and to identify particular subgroups of the population who may be at higher risk of nutritional and dietary deficiencies.
The authors have consulted a range of literature and constructed a broadly narrative review, making reference to numerous guidelines, surveys, nutritional databases and other study data. It is not possible to consider this a systematic review, as the methods by which publications were identified and assessed for inclusion are not explained in the report: it is possible that other literature relevant to the issue of child diet in the UK has not been considered in the review.
What did the research involve?
In summary, the researchers have gathered together various guidelines, and data from surveys, databases and studies and provided a narrative discussion of their findings. As mentioned above, the methods used to gather this information are not explicitly provided and therefore cannot be evaluated.
The authors discuss the background to their study, saying how the prevalence of child obesity is increasing with age. For example, they refer to data from the National Child Measurement Programme 2007/08 that indicates that 10% of children in reception classes were classified as obese compared with 18% in Year 6 classes (aged 10-11 years). They say that type 2 diabetes is becoming more common in children and that poor dietary factors can contribute to the early onset of other chronic diseases.
What were the basic results?
It is not possible to give a full account of the paper’s narrative, but a summary of some of the discussion points are given below.
The National Diet and Nutrition Survey
The NDNS collects cross-sectional survey data every 10 years and has found that the diet of UK children appears to have improved in recent years. However, intakes of several key nutrients remain below dietary recommendations. It suggests that:
- The diets of UK children are particularly lacking in fruit and vegetables, oily fish and fibre.
- Children over 11 years would be expected to reach close to the adult target of 400g/day of fruit and vegetables, but the survey found average consumption of 200g/day in 15 to 18 year olds, and 170-190g/day in younger children.
- Children in households receiving benefit and those from manual work social class groups were more likely to have low fruit and vegetable intake.
- Average intakes of oily fish ranged between 5-10g/week in those aged 4-18 years, which is equivalent to less than 0.1 portion/week; lower than the recommended two portions per week.
- The mean intake of wholegrain fibre in children aged 4-18 years in 1997 was 12g/day; similar to the intake of 13g/day reported in 2005. Adolescents are expected to increase their intakes of fibre of towards the adult recommendations of 18g/day, but there are no guidelines for younger children.
Recommended micronutrient intakes do not appear to be met by all UK children. For example:
- recent survey data shows that 58% of females meet their recommended daily intake of iron.
- studies show that vegetarian girls consuming fibre-rich diets are most at risk of iron deficiency.
- data published in 2007 shows that calcium, magnesium, zinc, potassium, iodine and folate deficiencies appear to be increasingly apparent in children from low-income groups.
There are also concerns that many UK children are vitamin D deficient. The 2008 Northern Ireland Young Hearts Project reported daily intakes of 1.7 microgrammes in children aged 12-15 years, while 1997 NDNS data estimated that low-income children consume on average about 2 microgrammes of vitamin D/day. The European Recommended Daily Allowance they report to be 5 microgrammes.
Vitamin and mineral supplements
Data published in 2009 showed that vitamin and mineral supplements made a significant contribution to overall nutrient intakes in children aged 2-17 years, with supplement use varying between ethnic groups. Asian or Afro-Caribbean children were most likely to take supplements. Another publication concluded that children most in need of supplements are often the least likely to take them.
The authors say there is evidence that healthy eating messages on saturated fat are being implemented. They also say that NDNS data shows a decline in intakes of total fat, saturated fat and trans-fatty acids (said now to be less than 2g per day for all age groups).
How did the researchers interpret the results?
In their discussion the authors conclude that while there has been progress in improving children’s diets, further improvements are still needed. They also say how the lack of child-specific
targets for fibre, long-chain fatty acids, vitamin D and fruit and vegetable portions makes it difficult to properly evaluate children’s diets for these important dietary components.
This narrative review discusses national guidelines, surveys and study data to assess the dietary intake of children in the UK and compare it with the pattern seen over the preceding decades. The study should not be considered to be a systematic review, as the methods by which publications were identified are not explained in the report, and it is possible that the authors have not included other literature relevant to the issue of child diet in the UK. It should therefore be considered primarily as a narrative based on the authors’ consideration of the literature that they have evaluated.
While a rise in type 2 diabetes in children was mentioned in the introduction of the review, the focus of this narrative was dietary patterns themselves rather than their potential health consequences. As such the article raises some interesting points for consideration, but should not be taken as a predictor of a “diabetes timebomb” or to provide an accurate estimate of how children’s nutrition today will impact on disease in the future.