Teaching Kids That What They Eat Matters
Understanding the impact of food choices on behaviour, brain health and development
Kids are not generally renowned for being health-conscious with what they eat. In fact, what teens are more typically known for is a fondness for fast food and soda. Active kids and teens who are into sport often do not give much thought to their food choices - after all, they have a happy knack for staying lean whatever they eat. From a performance perspective this seems short-sighted - high-performance engines require the highest quality of fuel and they are quite literally putting sugar in the gas tank. But there are bigger problems. The growing rates of obesity among kids and teens indicate there is a need to give kids’ eating habits urgent attention. Beyond the visible deleterious effects on physical health, there is growing evidence of hidden threats, including serious negative consequences for brain development, behaviour and mental health.
So what are the problem foods that pose the biggest risks and what are the potential ill effects that parents and kids need to be made aware of? Let’s start with the first question. The threat lurks in essentially every supermarket, convenience store, vending machine, food court and cafeteria, which gives them the umbrella term ‘convenience foods’. Convenience foods are ultraprocessed, tend to be high in both fat and refined sugars (notably fructose-rich corn syrup) and are designed to be highly palatable. Broadly, this includes junk food, snack foods and many other food items that dominate the supermarket shelves away from the fresh food aisle.
Like other mammals, we have evolved to crave and seek out food sources that provide the specific array of nutrients we need at a given time and our taste buds are similarly geared to sensing the nutrient content of the foods we eat. By design, ultraprocessed convenience foods break the usual relationship between nutrient content and palatability. They are tasty despite being low in nutrient quality and these foods are also highly calorific. The combination of high palatability with low density of key nutrients (especially protein and fibre) causes a tendency to consume these foods in excessive amounts despite their high calorie content, as the body’s usual signals that cue us to stop eating are not triggered. For these reasons convenience foods are known to drive obesity.
Convenience foods are prevalent to the point of being ubiquitous - a telling sign is that regular consumption of these foods is termed ‘the Western Diet’. Ultra-processed, high fat, high sugar convenience foods are everywhere, even in environments such as school cafeterias where we might hope that kids would be presented with food choices that are more conducive to the health of young bodies and brains. Convenience foods are heavily marketed with advertisements specifically aimed at children and teens. In the societies we live in, it is considered quite normal for kids to consume these foods on a daily basis.
It is not difficult to see why these foods are so popular, especially for busy parents and kids who just want to grab something tasty on the go. They are relatively cheap, readily available, highly convenient and designed to be very tasty. There are, however, darker reasons behind their mass consumption.
It is becoming evident that habitual snacking on these foods hijacks the brain’s reward system in a way that leads us to crave these foods, whilst simultaneously making healthy whole foods less palatable to our taste buds. In other words, regularly eating these convenience foods affects our brains in ways that changes our eating behaviours. This creates a vicious cycle of compulsive consumption that in turn reduces the inclination to choose healthier options.
We tend to assume that kids’ attitudes and behaviours towards food will mature as they do. However, this ignores the considerable scope for real damage to be done in the meantime. Eating behaviours are in part socially-driven, such that changes in the preferences of their maturing peer group over time is a factor. However, the brain also has a lot to do with dietary habits. Habitual consumption of convenience foods can lead to the rewiring of kids’ brains as they are developing and can even alter parts of the brain that are critical for regulating behaviour. All of this means that the eating habits of children and teens are more consequential and the effects are more enduring than we think.
Adolescence is a critical period for brain development and it is also a phase in their development when kids are especially prone to the allure of junk food and snack food. Part of the mix is the natural urge to assert independence and meal times are no exception, plus socialising with their peers often involves copious junk food. Going against the grain in this regard is especially challenging at a time when kids are hyper-conscious of social judgement, which means that the urge to conform is never greater.
Resisting these social forces is all the more challenging given that the area of the brain that equips kids to choose to do the harder thing when it is the right thing and in the best interests of their future self is very much still under construction (and will continue to be until they reach their early 20s). For similar reasons, how the teenage brain processes rewards is highly prone to being hijacked. Adolescents are notorious for being impulsive and engaging in sensation-seeking behaviour - sometimes recklessly and to excess. These are characteristic features of this phase in their development. As parents of teenage boys will testify, they also have voracious appetites that can empty a fridge as soon as it is filled. Convenience foods are engineered to not only satisfy these urges but also feed the craving and reinforce compulsive eating behaviours, almost as if they were custom-designed to take advantage of these traits.
What is evident is that regular consumption of convenience foods has the potential to shape and condition kids’ eating behaviours in an adverse manner. Whilst this is clearly a problem, more alarming is that this may lead to enduring neurological changes that alter the function of key parts of the brain and even reduce the volume of brain matter. Downstream negative effects of habitual consumption of highly processed snack foods in early life include cognitive deficits, impaired memory and lower IQ. Similarly, kids’ eating habits during the critical period of adolescence can have a lasting impact on their ability to regulate behaviour once they reach adulthood.
The ‘Western diet’ of junk food and ultraprocessed snack foods is implicated in neurodevelopmental disorders such as ADHD, the rates of which continue to spiral upwards. There is likewise mounting evidence that heavy convenience food consumption might be contributing to the worsening mental health among children and teens. The data indicate that boys may be particularly susceptible. The link between poor dietary habits and anxiety is most evident in adolescent males and boys are diagnosed with neurodevelopmental disorders at much higher rates.
All of that said, it is important to not engage in scare tactics. To be clear, these issues arise with regular consumption and over-consumption. The occasional treat or visit to a fast food outlet is not likely to cause profound ill effects. Likewise, it is important to emphasise that there is a way out for those kids and teens who are excessive consumers of convenience foods. Happily, the adverse changes described do appear to be reversible if teens switch to more healthy diet.
Good nutrition is a well established pillar of sports performance. What is far less widely recognised is that a high quality diet during the formative childhood and adolescent years is also vital for brain health and development and this is where we need to raise awareness. Understanding that childhood food choices can have an enduring impact on our behaviours and even brain development is crucial. Kids and parents need to know what is at stake. Part of the solution is to arm kids with the knowledge to resist marketing and social cues and enable them to make better informed choices. In the process, we can help them avoid falling into bad habits that will make this more difficult.
Physical exercise is among the most potent means we have at our disposal to counteract the negative effects described. Participation in sport and engaging in physical exercise on a regular basis supports physical, metabolic and brain health and ameliorates the negative health impacts of poor dietary habits. Importantly, physical exercise also boosts kids’ ability to regulate their own behaviour and thus confers some protection against having their food choices and eating behaviours hijacked.
For the aspiring young athlete, exercising agency in their day-to-day food choices offers ample scope for developing their self-regulation capabilities. As kids reach early adolescence we can help them to meet the challenge of resisting momentary temptations and choosing to act in the best interests of their future selves as they pursue their sporting aspirations. Beyond the opportunity to practise self-discipline, making good choices and maintaining good habits in the crucial area of nutrition is a powerful way to affirm their commitment to their chosen mission.