Anti-obesity campaigns are making British teens overestimate their weight and could even be driving them to obsessive dieting, a new study warns.
They found 60.5 per cent of British girls and boys aged between 14 and 16 had exercised to lose weight, compared to 6.8 per cent in 1986.
More than ever, teenagers are exercising with the specific aim of losing weight, rather than for the love of the activity or the feeling of being healthy.
While this is good news for cutting childhood obesity, researchers are concerned the push to ‘fight the fat’ may be tipping healthy young people of a normal weight towards eating disorders like anorexia.
More kids are dieting specifically to lose weight than in 1986. Experts believe anti-obesity drive could push teens of a normal weight towards eating disorders
According to government figures, 20.1 per cent of children aged between 10 and 11 in England are obese and 14.2 per cent are overweight.
Government strategies for the prevention of obesity in childhood include raising awareness of food caloric intake (partly by using the ‘traffic light’ system on food packaging), introducing the Soft Drinks Industry Levy in 2018 and increasing anti-obesity advertising.
But this growing focus on obesity prevention ‘might have had unintended consequences’, experts write in a new paper.
‘Our findings show how the way we talk about weight, health and appearance can have profound impacts on young people’s mental health, and efforts to tackle rising obesity rates may have unintended consequences,’ said study author Dr Francesca Solmi at University College London (UCL).
‘An increase in dieting among young people is concerning because experimental studies have found that dieting is generally ineffective in the long term at reducing body weight in adolescents, but can instead have greater impacts on mental health.
British Cohort Study
People born in 1970; data collected in 1986
Children of the 90s Study
People born 1991-92, data collected in 2005
Millennium Cohort Study
People born 2000-02, data collected in 2015
(Participants from all three cohorts were between the ages of 14 and 16 years.)
‘We know, for instance, that dieting is a strong risk factor in the development of eating disorders.’
Dr Solmi and her team at UCL investigated whether weight-control behaviours have changed in the three decades between 1986 and 2015.
To do this, the researchers reviewed data from 22,503 adolescents in the UK, taken from three different cohort studies representing children born in the eighties, nineties and noughties.
All participants from the three cohorts were aged between 14 to 16 years from the general population.
Researchers said the of the participants ranged across the full spectrum, from healthy to obese.
The adolescents were all asked questions about whether they were, or had been, trying to lose weight, whether they had dieted or exercised to lose weight and whether they perceived themselves to be underweight, about the right weight or overweight.
These personal estimates were compared to their actual height and weight measurements, including body mass index (BMI) – which indicates if one is of a normal weight, overweight or obese.
Subjects also filled out the Short Mood and Feelings Questionnaire (SMFQ) to gauge depressive symptoms.
SMFQ includes statements like ‘I felt miserable or unhappy’ that subjects have to rank on a three-point scale based on how they’ve felt in the last two weeks.
Out of 10,793 British kids from the most recent cohort (who were born between 2000 and 2002), 4,809 (44 per cent) had dieted and 6,514 (60 per cent) had exercised to lose weight, the team found.
42 per cent of 14 to 16-year-old girls and boys said they were trying to lose weight in 2015, compared to 28.6 per cent in 2005
This figure compared with 1,952 teens (33 per cent) of the same age dieting and 344 exercising (6 per cent) to lose weight out of 5,878 back in 1986.
Also of the most recent cohort, 4,539 (42 per cent) were trying to lose weight in any way, compared with 1,767 (28 per cent) in 2005.
Both girls and boys also became more likely to overestimate their weight from 1986 to 2005, and even more so by 2015.
But girls trying to lose weight were also more likely to experience depressive symptoms than in previous years.
While girls have consistently been more likely to diet to lose weight, the researchers found a greater increase over the years among boys doing so too.
Engagement in vigorous physical activity has remained relatively stable among adolescents over the past few decades – but is engaged in for different reasons, researchers estimate.
Traffic light food labels (pictured) aim to give consumers a straightforward and unambiguous indication about the fat, salt and sugar content of their purchases
‘It seems that young people are exercising for different reasons than they did before,’ said study author Dr Praveetha Patalay at UCL.
‘More adolescents seem to be thinking of exercise predominantly as a means to lose weight rather than exercising for fun, socialising and feeling healthy.
‘Societal pressures for girls to be thin have been around for decades, but body image pressures on boys may be a more recent trend,’ Dr Patalay.
Researchers add a warning voice to further plans to cut childhood obesity, including applying ‘exercise-equivalent’ labels to food packaging
Recent research suggests these labels – which would tell people how much exercise they would have to do to burn off the contents – would be successful by ‘guilting’ people into healthier choices and cutting national obesity.
For example, a 266g pack of milk chocolate digestives would carry a warning that it take more than two hours of solid running to burn off the calories inside for the average person weighing 80kg
A 266g pack of milk chocolate digestives would take more than two hours of solid running to burn off for the average person weighing 80kg. Researchers say exercise labels like these on food packaging will drive kids towards exercising to lose weight and could lead to eating disorders
But UCL researchers suspect exercise-equivalent labels would further reinforce the idea that exercise is more of a means to lose weight than anything else.
‘Media portrayals of thinness, the rise of the fitness industry and the advent of social media may all partly explain our results, and public health messaging around calorie restriction and exercise might also be causing unintended harm,’ said Dr Solmi.
‘Public health campaigns around obesity should consider adverse mental health effects, and ensure they avoid weight stigma.
‘By promoting health and wellbeing, as opposed to focusing on “healthy weight”, they could have positive effects on both mental and physical health.’
Dr Solmi pointed out that dieting can lead to eating disorders across the full BMI spectrum and not just among adolescents who are in the normal BMI range.
‘People generally tend to associate eating disorders with low weight, but eating disorders can occur at any weight – however, they tend to be overlooked in people who are not at a low weight,’ Dr Solmi told MailOnline.
‘We believe that the increase in dieting and exercising to lose weight, as well as in concerns with body image, that we observe are worrying trends, regardless of adolescents’ weight.
‘These behaviours are not only ineffective at long-term weight-loss, but are also associated with internalised weight stigma, depression, and eating disorders, all of which lead to poor physical as well as mental health throughout individuals’ lives.’
The research has been published in JAMA Pediatrics.
OBESITY: ADULTS WITH A BMI OVER 30 ARE SEEN AS OBESE
Obesity is defined as an adult having a BMI of 30 or over.
A healthy person’s BMI – calculated by dividing weight in kg by height in metres, and the answer by the height again – is between 18.5 and 24.9.
Among children, obesity is defined as being in the 95th percentile.
Percentiles compare youngsters to others their same age.
For example, if a three-month-old is in the 40th percentile for weight, that means that 40 per cent of three-month-olds weigh the same or less than that baby.
Around 58 per cent of women and 68 per cent of men in the UK are overweight or obese.
The condition costs the NHS around £6.1billion, out of its approximate £124.7 billion budget, every year.
This is due to obesity increasing a person’s risk of a number of life-threatening conditions.
Such conditions include type 2 diabetes, which can cause kidney disease, blindness and even limb amputations.
Research suggests that at least one in six hospital beds in the UK are taken up by a diabetes patient.
Obesity also raises the risk of heart disease, which kills 315,000 people every year in the UK – making it the number one cause of death.
Carrying dangerous amounts of weight has also been linked to 12 different cancers.
This includes breast, which affects one in eight women at some point in their lives.
Among children, research suggests that 70 per cent of obese youngsters have high blood pressure or raised cholesterol, which puts them at risk of heart disease.
Obese children are also significantly more likely to become obese adults.
And if children are overweight, their obesity in adulthood is often more severe.
As many as one in five children start school in the UK being overweight or obese, which rises to one in three by the time they turn 10.