Teenagers who turn their backs on a healthy lifestyle and turn to drink, cigarettes and junk food are significantly unhappier than their healthier peers.
New research also shows that 12-13 is a catalyst age when young people turn away from the healthy habits of their younger years and start to get involved in risky behaviours.
The research, which used information from Understanding Society, a long-term study of 40 000 UK households funded by the Economic and Social Research Council (ESRC), looked at the responses of 5 000 young people between the ages of 10-15 to questions about their health-related behaviours and levels of happiness. The results show that:
Young people who never drank any alcohol were between four and six times more likely to have higher levels of happiness than those who reported any alcohol consumption.
Youth who smoked were about five times less likely to have high happiness scores compared to those who never smoked.
Higher consumption of fruit and vegetables and lower consumption of crisps, sweets and fizzy drinks were both associated with high happiness.
The more hours of sport youth participated in per week the happier they were.
Researchers at the Institute for Social and Economic Research at the University of Essex believe the data showed that unhealthy behaviours such as smoking, drinking alcohol and taking no exercise are closely linked to substantially lower happiness scores among teenagers, even when socio-demographic factors such as gender, age, family income and parent's education are taken into account.
Twelve per cent of 13-15 year olds reported that they smoked compared with 2% of 10-12 year olds. The figures for alcohol consumption were even more striking with 8% of 10-12 year olds reporting having had an alcoholic drink in the last month rising to 41% amongst 13-15 year olds.
The research also showed that between the ages of 13 and 15, when young people are given more autonomy over their lifestyle choices, their food consumption becomes less healthy and their participation in exercise reduces.
Only 11% of those aged 13-15 years reported consumption of 5 or more portions of fruit and vegetables per day and even amongst the 10-12 year olds less than a fifth reported eating fruit and vegetables 5 or more times per day.
Dr Cara Booker, one of the co-authors of the research said: "What this research shows us is that young people across the social spectrum are failing to eat healthy balanced diets and are starting to consume alcohol at a young age.
This is storing up problems for later life, because we know that there are clear long-term links between health-related behaviours and well-being in adulthood. Helping young people to reduce damaging health choices as they start making independent decisions are important in order to reduce the number of adults at risk from chronic disease because of their low well-being and poor health-related behaviours."
(EurekAlert, March 2012)
Teen: health tips
Diet & Nutrition