From an evolutionary perspective, we have always eaten in order to live. But too many of us live to eat. Consequently, more than 1 in 5 adults are overweight, and more than a third of them obese. Today, with 24-7 access to food, a biological drive to eat high-calorie fare has rapidly evolved into a health burden.
The brain has developed a faulty anticipation of energy needs. Overriding evolution is a desire for the feel-good mood boost that many foods now bring us and which may be fostering an unconscious urge to overeat.
The human brain is easily tricked by pleasure foods as they confuse the brain’s regulating systems. In North America, it seems we get the most pleasure from refined carbohydrates, vegetable oil, and diet pop to name a few. Refined carbs – empty-calorie foods – may make us feel good, but because the brain seeks micronutrients and empty-calorie foods like white bread, pasta, cake and cookies don’t provide these micronutrients, the “eat more” signal typically stays on. It also turns out that vegetable oils – found in most snack food – may be making us stoned! Vegetable oil promotes snacking because new research suggests that it plays on endocannibinoid receptors much the same way that marijuana causes the “munchies.”
Sugar-free soft drinks also confuse our brain. When studies are done on diet soda drinkers, there is a diminished activation of an area in the brain associated with the food motivation and reward system. Decreased activation of this brain region has been linked with elevated risk of obesity. But besides the very direct and often negative impact these and other foods are having on our cravings, it seems we desire to keep filling up on them because they surge a “feel-good” hormone in the brain called dopamine.
Complex interactions between the nervous system, hormonal pathways, and immune system are at play when it comes to overeating. In fact, it’s not just overeating. Can’t put your blackberry down? Feel bored when you’re not at work? Late-night binge behavior? Believe it or not, all these things have a lot to do with dopamine – the neurotransmitter that’s heavily involved in the pleasure center within the brain. It’s released in high amounts during gratifying activities such as eating, sex, exercise, dancing and other enjoyable experiences.
The pathway between the brain and body is known as the neuroendocrine-immune supersystem. Symptoms of this system breakdown can sometimes appear as a hormone issue when in actuality, they can be attributed to a neurotransmitter imbalance. Keep in mind, dopamine is a neurotransmitter. Common symptoms include mood changes, focus issues, insomnia, fatigue, anxiety, and, in particular, compulsive overeating resulting in weight gain. As a brain neurotransmitter, dopamine influences well being, alertness, learning, creativity, attention and concentration. Dopamine also affects brain processes that control movement, emotional response and is the source of the brain’s power and energy.
While too little dopamine can leave us craving food, sex or stimulation, too much can cause addictive behaviors. In a December 2008 study in the journal Nutrition & Metabolism, J. Reinholz and colleagues suggest that your brain uses dopamine to tell your body when to stop eating. Low dopamine levels may also play a role in overeating for people with a genetic predisposition to low dopamine levels.