New study shows children are less fat – but less fit. The ‘obesity crisis’ may be a fitness crisis

A long-term study by the University of Essex has found that, although the average BMI (body mass index) of children has fallen, their fitness levels are down, too. In short, they are less fat but also less fit.

The researchers said that one of the least fit children they tested in 1998 would be one of the five fittest in a class of the same age today.

In 2009 they found that child fitness had declined by eight percent over the previous decade. This time the decline is even greater – but the children were on average thinner than those monitored previously.

As Christopher Snowden points out, BMI is calculated by dividing a person’s height by their weight. The Essex study – which shows no correlation between lower BMI and increased fitness – lends support to the argument that it is of limited usefulness.

The researchers tested 300 pupils aged between 10 and 11. They expected that children with a lower BMI would perform better than the heavier children they measured six years ago, but that wasn’t the case.

‘Simply put, if you weigh less it is easier to run and turn so you should do better on our test,’ said Dr Gavin Sandercock, the project’s lead researcher.

‘But despite finding a lower average BMI in the children measured in 2014 than in 2008 we found the children still couldn’t run as fast, showing they had even lower cardiorespiratory fitness.’

‘Our findings show there is no obesity crisis in the schools we went to, as less than five per cent of pupils were obese and the average BMI is now below 1998 values. This would be good news if BMI was all we had measured, but our fitness tests tell a different story.’

The findings suggest that fitness has been declining at 0.95 per cent per year – over twice that of the international average. And male fitness levels are falling at a particularly alarming rate.

The Essex scientists are calling for a rethink on how children’s health is monitored. They would like to introduce child fitness testing in schools, which would measure a child’s ‘physical literacy’ at each key stage, as they do currently for academic subjects.

In the meantime, the study suggests that Britain’s much-publicised ‘obesity crisis’ may be less significant than a fitness crisis in our schools.


  • JessAskin

    I am not familiar with the details of this particular study.

    As a GP I would say that BMI is limited in its scope and we know this. But as a measure it does have a role. I expect that most Doctors usually consider a range of measures when they look at their patients to determine if there are issues. However, we need to be especially careful about all these measures when we consider children. We tend to look at “the whole picture” rather than any one measure.

    My own observation has been that childhood obesity is on the rise but it largely depends where in the country and what socio demographic group we are talking about. Nevertheless, there is no doubt that I see children who are far more obese than those that I saw when I started practising. What is far more noticeable is the rise in obesity of 40+ year olds. My clinical observation correlates well with many cross country observations.

    What I often find is the reluctance of people to accept that they are obese. There always is an excuse – with men it typically is that they play Rugby or that they are big boned. With women it is “their metabolic rate” or similar. It is in their genes. And so on. They then point to others who they think are “really fat”.

    Has fitness dropped? Well I don’t specifically measure this. But you would not be surprised to know that the Obese children that I see mostly don’t exercise in any meaningful way and similarly for older people.

    Having said that it is noticeable that there are lots of people in certain socio demographic groups who are exercising more than before. We see this via the rise in various sports e.g. cycling. Growth of Gyms and Gym memberships also suggests that more people are exercising.

    Does exercise happen in schools? My children in State schools have timetabled PE lessons. These lessons seem to me to be rigorous. We need to be careful about what we push to schools (or to Doctors). Both already are overloaded. In simple terms – most of us need to exercise more and eat less.

    • Tarek

      I have to agree with your observations; children are getting fatter unfortunately, and I lay this at the door of overconsumption of processed, sugary laden frankenfoods as well as less exercise. Years ago children were eating white bread, crisps and pudding yet did not enjoy anywhere near the amount of obesity as these were seen as a treat and not a staple part of the diet. They need role models in the form of adults doing their best to be healthy, but also need to be kept away from the kind of destructive advertising we see today, not to mention the cheap and plentiful availability of such unhealthy fare being served not only in shops and from vending machines but also school caffeterias. Sugar is addictive, to at the very least EXTREMELY habit forming, as is the proportion of sugar to fat in most junk food, something that happened by design. We wouldn’t tell an alcoholic to sit in a pub and not drink and whilst I’m not suggesting that most people are “sugar addicts” in the way we formally define addition, I will say that easy access to cheap processed food doesn’t help people eat healthy, especially when they are late coming home from work/school, hungry and in many cases not particularly prosperous. A pound can buy you a couple of filling Kitkat chunks; a similar amount spent on fruit will buy you little fruit that will not satisfy any hunger. Add to this of course the fact that 2x week PE lessons of my youth have given rise to 1x week or even no PE lessons and that many children do not have the freedom to play outdoors as they did many years ago its no surprise that the two pillar of obesity i.e. lack of exercise and unhealthy food have been so destructive.