Fast food linked to depression in kids

Back in 2012 we wrote about a study that looked at the relationship between eating fast food and depression in adults. In a sample of nearly 9,000 adults, those who ate the most fast food - about 22 times more, by weight, than those who ate the least - were 40% more likely to report developing depression over the course of the 8-year study.

The World Health Organization estimates that at least 20% of all children suffer from a mental health disorder, and as many as half of all mental health issues are known to first appear in adolescence. With childhood obesity a major concern as well, a group of researchers in Pakistan sought to determine if there was a link between symptoms of mental health disorders and diet in children (Nutrition 2014;30(11-12):1391-1397).

They made use of data gathered through a large-scale national sample of children aged 6-18 (over 13,000 of them) and their parents. The students responded to two questionnaires: one asked them to describe how often they felt anxiety, insomnia, confusion, sadness or hopelessness, or worthlessness, and also how often they were in a fight, bullied others, or were themselves bullied. The second questionnaire was about diet and included questions about how often they ate different types of junk food, including sweets (including cookies, cakes, or candies), sweetened beverages (soda or other soft drinks), fast foods (hot dogs, hamburgers, pizza, or fried chicken), and salty snacks (such as potato chips, popcorn, or pretzels).

The parents responded to questions relating to demographics, including their family size, economic status, education, and general family history.

The researchers then correlated the diets of those children reporting mental distress or engaging in violence with those who did not. After taking into account such variables as family history of chronic diseases, mother's education, physical activity, economic status, and the body mass index of the child, they found that those children who consumed fast foods at least weekly were up to 20% more likely to experience depression, 46% more likely to experience insomnia, 23% more likely to experience anxiety, and 29% more likely to experience feelings of worthlessness.

Worse yet, those who ate fast food on a daily basis were nearly 2 times as likely (94% more likely) to experience depression. They were also twice as likely to experience feelings of worthlessness and nearly twice as likely (81%) to experience anxiety.

The relationships between the other types of junk foods - soft drinks, salty snacks, and sweets - and weekly or daily intake also showed increased risks of mental distress, but not as strong as fast food.

What this means for you

Once again we must caution you that correlation does not mean causation: eating fast food was related to mental distress, but it's impossible to tell for sure from this study that eating fast food is in any way causing this mental distress. It's worth noting, however, that the research team took into account body mass index in their analysis - being overweight, which might be a source of some of these negative feelings, is unlikely to be a factor for that reason. This does underscore the importance of a healthy diet for children and adolescents - body and mind.

First posted: November 12, 2014