Obesity-related eating issues are in the news again. This time new research indicates that the physiological dynamics of overeating are the same as drug addiction. Compulsive Eating Shares Addictive Biochemical Mechanism With Cocaine, Heroin Abuse, Study Shows comes from Science Daily. The article summarizes a Scripps Research Institute study that was published recently in the journal Nature Neuroscience.
The study examined the brain chemistry of rats that were fed high-fat, high-sugar diets similar to human junk food. The rats quickly became obese and at the same time their brain chemistry showed striking changes. Pleasure centers in their brains changed and became less responsive. The result was the rats had to eat more and more in order to stimulate these regions. These dynamics of food addiction mirror those of rats addicted to cocaine and heroin. Paul J. Kenny, one of the scientists who conducted the study said,
“It presents the most thorough and compelling evidence that drug addiction and obesity are based on the same underlying neurobiological mechanisms. In the study, the animals completely lost control over their eating behavior, the primary hallmark of addiction. They continued to overeat even when they anticipated receiving electric shocks, highlighting just how motivated they were to consume the palatable food.”
A fascinating development in the study came when researchers replaced the junk food with nutritious food: the rats refused to eat. They starved for nearly two weeks after the change.
What seems to be happening to these rats (and likely to obese humans) is that consumption of highly pleasurable food overstimulates and dulls the reward centers of the brain. More food (or drugs) are needed to stimulate feelings of reward and pleasure. Without getting too technical, the neurotransmitter dopamine and it’s receptors in the brain are the key elements here. Dopamine is released in the brain by pleasurable experiences such as drug or food consumption. Consume too much of either and the brain is flooded with dopamine which is essentially bad for dopamine receptors. Over time the brain actually undergoes physical changes and addictive behavior becomes normal and very difficult to change.
The big issue to me is that overeating and obesity are very complex and not at all simple matters of will power. Personal trainers and nutritionists must realize that the brain function of the obese person is very different from the non-obese person. Simply instructing someone to eat differently rarely works and now we know very specifically why.
To that point, I’m skeptical of our various efforts to educate the public on the caloric content in our food (first in NYC and most recently on a national level.) Similarly, it seems that small taxes on soda do little to curb consumption of the sugary junk. Simply putting the information in front of our eyes or enacting a slight monetary penalty isn’t enough and I don’t believe there are many ways government can affect our food choices. (I would be curious though to see the effects of eliminating subsidies for corn, wheat and soybeans. These subsidies keep the price of junk food–which is actually quite complex if you look at the ingredients–artificially low. So this addictive food is also dirt cheap. You and I are paying for this with our taxes!) That said, my hope is that those battling to lose weight won’t give up and resign themselves to poor health by saying “I’m addicted. There’s nothing I can do.”
From what I’ve seen of successful weight loss seems very similar to what I know of overcoming addiction. That is, the individual must decide to make a change for him or herself. Until the individual knowingly makes a firm decision to change no amount of preaching, pushing or cajoling by friends, a spouse, or parents will make the difference. And it is hard work. Perhaps now by recognizing the brain chemistry of over eating we can develop more effective strategies to slim down.