What is the FTO gene?
/Dr. Heatherton's biological discovery and its link to childhood obesity
Obesity, especially childhood obesity has become a global epidemic in recent years. Studies have gone back and forth on whether genetics, parenting, society, or personal decisions are primarily to blame.
Dr. Todd Heatherton, Professor in Human Relations in the Department of Psychological and Brain Sciences at Dartmouth College came to StFX in to discuss his research on self-regulation and its impact on obesity.
He defined self-regulation as either not doing something you want to do and inhibiting something rewarding or doing something you do not particularly want to do in order to initiate healthy behaviours. He went on to say that self-regulation problems on campus include cheating, eating disorders, addiction to social media, drugs, alcohol, and even sexual assault.
The Balance Model, a study done by Dr. Heatherton and his colleague Dr. Wagner in 2011, examined threats to self-regulation and, since eating activates reward regions in the brain, if pictures of food could eventually activate the same reward regions eating does. Heatherton’s research question became whether cue reactivity - reacting to pictures of food in this case, could predict whether a student would gain their ‘freshman 15’.
Self-regulation is the balance between reward and control and self-regulation failure is described as the ‘breakdown between reward and control which then results in an increased activity in brain reward regions.
Self-regulation failure, therefore, is a result of resource depletion, the idea that the ability to control oneself can be depleted over time. Dr. Heatherton proposed that resource depletion can be improved with specific training. He goes on to say that threats to self-regulation can have more of an impact on some people than others.
In regards to childhood obesity, some people suggest that the cause is an exposure to fast food advertising and that obese youth may simply be more responsive to food commercials than others. In a study conducted by Heatherton et al., they studied 40 youth between the ages of 12 and 16, twenty of which were obese and the others, of matching sex and age, were of average weight. Heatherton studied brain reactivity in response to food commercials and whether obese adolescents had a stronger reaction.
Interestingly, what was found was that in the overweight youth, their somatosensory networks were active when viewing the commercials, that is, the studies showed that they started to salivate and chew, which was not the result with those of average weight.
Heatherton suggested a few different reasons for why some obese children show greater cue responsivity. He said that genetically, some children simply find food cues more rewarding, which influences the balance between reward and control. Others may have less self-control and therefore a weaker executive system, which, some would speculate, is a result of societal influences. As a result, frontal areas became easy to blame as the reason for childhood obesity.
Dr. Heatherton and his colleagues discovered that the FTO gene, fat mass and obesity-associated, had direct relation to chances of a child becoming obese. In a study performed, those found to possess the FTO gene, even at a young age, were already significantly heavier than their peers and reacted immensely to cue reactivity in reward regions. That is, these children reacted much more to pictures and commercials of food.
To further his study, Dr. Heatherton examined how self-regulation can be strengthened. He discovered that cue reward brain activity can predict real world self-regulatory behaviours and outcomes. Those with greater reward responses are more susceptible to self-regulation failure, meaning no activity because people are instantly regulating in order to resist food.
Childhood obesity is therefore associated with the FTO gene, resulting in increased food cue reactivity, meaning that there is, in fact, a significant genetic component, which, combined with increased media and advertising results in an unhealthy weight. The solution is not to build will-power but to reduce reward responses with food, which would, as a result, make it easier to inhibit unhealthy behaviour.
Obesity is a growing issue and does not have one explanation, nor one solution. However, with the work of Dr. Todd Heatherton, the FTO gene is now a subject of research, and children can be taught at a young age to reduce reward responses to lead to a healthier life.
