Thursday May 15 2014
Is the UK Europe's fat man?
“Too much sugar, salt and fat: healthy eating still eluding many Britons,” The Guardian reports, while the Daily Mail rather bizarrely warns of a “fruit juice timebomb”. Both papers are covering a major survey that looked at the nation’s eating habits over recent years.
The survey found that, overall, adults and children are eating too much saturated fat, added sugar and salt. We are also not getting the recommended levels of fruit, vegetables, oily fish and fibre that our bodies need.
Who produced the survey?
Public Health England, an agency of the Department of Health, has released data from the National Diet and Nutrition Survey (NDNS) from 2008 to 2012. The NDNS is undertaken by Natcen Social Research, MRC Human Nutrition Research and the University College London Medical School. It is funded by the Food Standards Agency (FSA) and Public Health England.
How was the national diet and nutrition survey carried out?
In 2008, 2009, 2011 and 2012, a randomly selected group of people aged 18 months or more, from 799 different postcodes, were invited to take part in the survey, via post. Response rates to the survey were 56% in Year 1, 57% in Year 2, 53% in Year 3 and 55% in Year 4. Up to one adult and one child were selected from each address, and this gave a sample size of 6,828 people over the four years (3,450 adults and 3,378 children).
An interviewer recorded background information during a face-to-face interview with the adult, child or child’s parent or guardian, to determine their socioeconomic status. They also took height and weight measurements, and were then asked to complete a four-day food and drink diary using estimated portion sizes. Those who recorded at least three days of consumption were given a £30 voucher for a high street shop.
Participants were asked to complete a 24-hour urine collection and have a fasting blood sample taken by a nurse, alongside other measures.
About half the participants agreed to this.
Results were split for children of different ages, adults aged 19 to 64 and older adults aged 65 and over. Comparisons were also made when combining results from 2008/9 and 2011/12.
What were the main findings of the diet survey?
The survey went into extensive detail about the diets of participants, who were deemed to represent "typical" British people.
Fruit and vegetables
Only 30% of adults and 41% of older adults were eating or drinking the recommended five portions of fruit or vegetables a day, and only 10% of boys and 7% of girls aged 11 to 18 got their “5 A Day”. Adults aged between 19 and 64 consumed on average 4.1 portions of fruit or vegetables per day – a portion less than the minimum amount recommended for good health.
Estimated salt intake was based on the amount excreted in the urine. On average, this was higher than the recommended levels for all groups of children and adults, except girls aged 7 to 10 and older adults. Salt intake was estimated to be higher in males than females.
The average intake of total fat met the recommended level (no more than 35% of food energy) in all age groups apart from men over 65, who were just over the recommendation, with 36% of their food energy coming from fat. However, the average (mean) intake of saturated fat exceeded the 11% recommendation in all age groups (coming in at 12.6% for the adults surveyed).
Read more about fat in your diet.
Non-starch polysaccharide (dietary fibre) for adults and older adults was 13.7-13.9g per day, which is below the recommended minimum of 18g.
Oily fish consumption was less than half the recommended one portion per week in adults.
Average (mean) intake of non-milk extrinsic sugars (added sugars – such as sugars added to some fruit juices and soft drinks) was higher than the recommended limit of 11% for all ages. The levels came in at 14.7% for children aged 4 to 10 and 15.6% in children aged 11 to 18. The main source of this sugar was soft drinks and fruit juice, which accounted for 30% of the intake for those aged 11 to 18.
Read more about sugar in your diet.
Iron and minerals
Average (mean) intake of iron was below the recommended levels for women and girls aged 11 to 18, and intake was below the lowest threshold in 23% of women and 46% of girls in this age group. Intake of calcium, zinc and iodine was also low. The intake of other minerals such as potassium, magnesium and selenium were below recommended levels in all age groups, except children aged under 11. Read more about minerals in your diet.
Blood cholesterol levels
A third of adults had cholesterol levels high enough to place them at a marginally higher risk of cardiovascular disease, which is one of the main causes of death in England. A further 10% of adults had cholesterol levels that moderately increased their risk, with a further 2% having a high risk of cardiovascular disease.
Vitamin D levels
Low vitamin D was found in a proportion of all age groups, which included 7.5% of children aged 18 months to 3 years, 24.4% for girls aged 11 to 18, 16.9% in men over 65 and 24.1% in women over 65.
Comparison between 2008/9 and 2011/12
There were very few changes in food consumption between the two time points; in 2011/12, the average total fat was lower, but there was a higher carbohydrate intake.
Were there any limitations to the nutrition survey findings?
The survey asked for food and drink consumption over four days, and weekends were over-represented. This is because eating habits are known to change over the weekend. This means that estimating the overall food consumption based on the four days could be inaccurate.
The survey is also reliant on people’s own assessment of portion size and intake. However, the survey was conducted as a food diary kept over 4 days, which should be more accurate than a commonly used method of relying on consumption recall in the previous 24 hours or past few days. The report suggested there may have been under-reporting of calorie intake.
What are the implications of poor diet on people’s health?
The findings are concerning as the risks of a poor diet are quite clear, for example:
What does this mean for those trying to improve Britons’ health?
There have been numerous health campaigns stating the benefits of eating at least five portions of fruit and vegetables a day, as well as limiting sugar, salt and saturated fat.
It would seem that, based on this survey's findings, these core messages may not have prompted dietary improvements for many people. However, they may have had impact in preventing people’s health from worsening – there is some evidence that since 2009, obesity rates have stopped rising.
There could be numerous reasons for the public health messages failing to lead to a widespread change in eating patterns. For example, many more people may now be aware they should be eating at least five portions of fruit and vegetables a day, but choose to ignore the message. Some commentators have also argued that some food manufacturers may be “manipulating” the 5 A Day message with confusing labelling.
Complimentary explanations include the fact that people want to eat healthily, but find many barriers to doing so, such as being unable to easily get healthy foods that are cheap and easy to prepare. Another explanation is that people are living in what is known an “obesogenic environment”. This is an environment that “promotes” obesity – such as working in an area that has plenty of takeaway burger and kebab shops, but no fruit and veg sellers.
Public health officials want to make healthy choices easier, so that people who want to eat healthily can do so. Doing so involves raising awareness of what is considered a healthy diet from a medical standpoint, so people can make informed choices about whether their own diet is healthy and make changes to their diet if they want to.
However, some critics argue that as well as employing a “carrot”, it may be necessary to employ a "stick" and “punish” people for unhealthy eating habits. One such idea is the controversial concept of a sugar tax, which would deliberately make foods high in added sugar more expensive.
Changing the eating habits of the British public is possible, but may take some time.
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.