A recent study suggests that the pleasure sensors in our brains could be the main driving factor behind weight gain in adolescence and body fat later in life – meaning that many of our bad eating habits are picked up when we are teenagers, making them more difficult to break as we get older.

The new research, published by Monash University, argues that it is actually brain health which is a more accurate indicator of body composition and body fat, rather than BMI which has traditionally been used.

Researchers found that an individual’s body fat percentage correlated with the size of their medial orbitofrontal cortex (OFC) – a region at the front of the brain that is involved in reward processing of food cues.

Essentially, those with a larger OFC experience higher levels of pleasure and joy from eating, meaning as a teenager they begin to associate eating food with positive feelings, making it harder to eat well and make controlled, healthy choices when it comes to food as an adult.

“We know that both reward-based learning and executive control are compromised in people who are overweight or obese,” said lead scientist Dr Naomi Kakoschke. “People with excess weight show heightened responsivity to highly palatable food cues, such as television commercials for food, and less ability to control those unhealthy urges.”

The study examined the association between body fat (an index of weight severity), impulsivity (a vulnerability factor for obesity) and brain structure in 127 people across the body mass index (BMI) spectrum.

“Studies have repeatedly shown that reward sensitivity is elevated in people with obesity, particularly for those with binge eating disorder. We hope future studies can point to brain health as being a more accurate indicator of body composition and body fat than BMI,” Dr Kakoschke concluded.