We all know that diet plays an important role in health. It clearly plays a role in weight, diabetes, heart attacks, and strokes. Most people, however, aren’t too worried about these things in children. These are usually diseases of older people, so most parents don’t think about them when it comes to their children. Many parents don’t worry too much about what their kids are eating. They’re young, after all, so they can usually burn off any extra calories. Newly published research, however, raises concern about this approach.
The research, published in JAMA Psychiatry, suggests that two factors closely linked with diet — insulin levels and obesity — may be strong predictors of which children go on to develop serious mental illness. The researchers followed almost 15,000 children from ages 1 to 24. They measured fasting insulin levels at 9, 15, 18, and 24 years of age, and body mass index repeatedly over the 24 years. They then measured the children’s risk for depression and psychosis at 24 years old. What they found was alarming.
Children who had persistently high insulin levels (a sign of insulin resistance) beginning at age 9 were five times more likely to be at risk for psychosis, and three times more likely to already be diagnosed with a psychotic disorder, usually bipolar disorder or schizophrenia. These are devastating disorders that can ruin lives. These children were also at somewhat higher risk of depression, but it wasn’t a statistically significant difference.
Children who had a significant increase in body mass index around the time of puberty were four times more likely to develop depression by the time they turned 24. They were also more likely to develop a psychotic disorder, but this difference wasn’t statistically significant. With depression now the leading cause of disability in the world, it’s not a disorder to take lightly.
Unfortunately, this research can’t tell us for sure if changing diet in childhood or adolescence can make a difference, but there is reason to believe that it might help. It will certainly help to address obesity and the risk for diabetes, which are no small matters.
What can parents do?
- You already have access to your child’s body mass index (BMI). This is measured annually at the pediatrician’s office. Find out if your child’s BMI is in the healthy range. Pay particular attention to significant increases in BMI around the time of puberty, according to this research.
- Ask your child’s pediatrician if he/she will check a fasting insulin level for your child. This could be particularly important if you have a family history of serious mental illness.
- If either the BMI or the fasting insulin levels are abnormally high, you and your child can do something about this. Dietary interventions have been shown to help reduce weight and insulin levels.
What type of diet is recommended?
Sadly, this is where there is tremendous controversy. The Dietary Guidelines for Americans have been around since 1980. Unfortunately, since that time, rates of obesity and insulin resistance have skyrocketed. The guidelines change every five years. The most recent version of the guidelines, issued in 2020, didn’t include any research related to weight loss or insulin resistance, so it’s not clear if those guidelines will help people address these issues if needed.
Some people are recommending the elimination or reduction of processed foods in favor of eating primarily whole foods, such as meats, fish, poultry, vegetables, and fruits. The paleo and Whole 30 diets are examples of such diets.
For addressing insulin resistance, there is some evidence that the Mediterranean diet can help. Low carb diets can also help. In 2019, the American Diabetes Association introduced guidelines which include low-carb and very-low-carb diets as one way to reduce blood glucose levels and improve insulin resistance. They reported that low-carbohydrate eating patterns “are among the most studied eating patterns for type 2 diabetes.”
In the end, if your child is having problems with weight or high insulin levels, you should discuss this with your child’s pediatrician and develop a plan. Obviously, you’ll also need to discuss this with your child. It will be important to develop a plan that he or she is willing to try. Ideally, the entire family should make a change, as it will increase the likelihood that your child can stick with the plan, too.
Christopher M. Palmer, M.D., is a Harvard psychiatrist and researcher working at the interface of metabolism and mental health. He is the director of the Department of Postgraduate and Continuing Education at McLean Hospital and an Assistant Professor of Psychiatry at Harvard Medical School.