Eighteen per cent of school children who took part in two health surveys carried out a year apart admitted they had eating problems, according to research published in the latest Journal of Advanced Nursing.
Thirteen per cent admitted eating problems in either the first or second survey and a further five per cent reported problems in both surveys.
Students who had ongoing eating problems were more likely to report multiple psychological problems and health complaints.
"For example we noticed that students who reported suffering from anxiety earlier in adolescence were 20 times more likely to have ongoing eating problems" says Lea Hautala from the Adolescent Psychiatry Clinic at the University of Turku, Finland.
"And teenagers who were dissatisfied with their appearance only had recurring eating problems if they also reported anxiety earlier in adolescence."
Researchers from the University surveyed 372 students aged between 15 and 17, repeating the survey after one year with the same pupils. 57 per cent were girls and 43 per cent were boys.
"A total of 66 students reported eating problems - 23 only reported problems in the first survey, 24 only reported them in the second survey and 19 reported them in both surveys" she adds.
"Students who had previous problems with anxiety were much more likely to suffer sustained eating problems, while those who didn't have previous psychological problems only experienced temporary eating problems and dissatisfaction with their appearance.
"We also found that girls were twice as likely to report eating problems on one occasion than boys and five times more likely to have ongoing problems."
When the researchers compared average results across the two surveys for students with persistent problems and no problems they discovered that:
- 70% of students with persistent problems reported one or more health problems (abdominal pain, dizziness, fatigue, headache and insomnia), compared with only 40% of the students with no eating disorders.
- 47% of students with persistent problems reported anxiety, compared with 12% of non reporters.
- 31% reported depression, compared with 5% of non reporters.
- 77% were unhappy with their weight and 46% with their appearance. This was much higher than the 8% and 18% reported by students without eating problems.
Despite this, when the researchers looked at the height and weight records kept by the school nurses, they found that even students with persistent eating problems were more likely to be normal weight than over or underweight.
63% of the students who reported eating problems were normal weight, compared with 79% of the students who didn't report any eating problems. And 37% were overweight and none were underweight, compared with 20% and 1% of the students without problems.
The researchers also found higher levels of psychological problems and health complaints in students who only reported eating problems in one of the two surveys.
"Our study backs up previous research that shows that eating problems often fluctuate in children of this age and in 50 to 60% of cases last about one to two years" says Lea Hautala. "However in ten per cent of cases their eating problems can persist into adulthood.
"Although almost a fifth of the students who took part in our study reported eating problems at some point, these problems clearly sorted themselves out in the majority of cases. However, one in twenty students continued to report problems.
"We believe that our results point to the need for schools to screen adolescents with psychological problems or multiple health complaints for eating problems, as these are the two key predictive factors that emerged from our study."