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NIDA. (2015, January 29). Obesity and Drug Addiction: The Brain Connection -- TedMed Talk by NIDA Director. Retrieved from

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The NIDA Blog Team
January 29 2015
Dr Nora Volkow at TEDMED
Sandy Huffaker for TEDMED.

A few months ago, NIDA director Nora Volkow, M.D., gave a talk at TedMed (a type of Ted talk for doctors) about her research studying the brains of people with obesity. Today the video of her talk is available, and you can see it below.

Nora is world-famous for her studies of the brain changes caused by drug addiction, and what she found was that similar changes happen in obese people. It makes sense if you think about it: Both addiction and obesity are diseases that involve the way the brain responds to rewarding things, things that make us feel good.

In her talk, Nora describes how the brain is a brilliant machine that evolved over millions of years when humans and our ancestors had to navigate a complex world that was mainly filled with dangers and very few rewards (like really tasty food). When we found a reward, like a beehive full of honey for example, we got very excited, gave those things all our attention, and braved the dangers to get the tasty prize inside.

Unfortunately, the ancient human brain hasn’t had time to adjust to the new reality of modern life, where tasty, high-calorie food is all around us and there are no obstacles to eating as much as we want. The peril for our health is obvious.

Nora admits that her brain is no different from anybody else’s: “The sensory assault by very appealing-looking food triggers a fight within my brain, to just give in and eat the pleasurable food NOW, even though I know I will feel guilty LATER, versus resisting the urge NOW so I can have a healthy meal LATER. It’s like having a war within my brain that is pulling me in two opposite directions.”

Unfortunately, many of the foods available to us are so tasty that they trigger a burst of the brain chemical called dopamine in the brain’s reward circuit that is similar to what some drugs produce. Over time, the reward circuit can get less sensitive to the dopamine—it needs the constant dopamine surge from fattening food.

This is what Nora found when she scanned the brains of morbidly obese people: Their reward centers were just like those of people addicted to cocaine.

Nora says: “In all of my years as a physician, I have never ever met a person who chose to be an addict, nor have I ever met anyone who chose to be obese. So, imagine what it must be like to be unable to stop doing something when you want to; no matter how hard you try, you give in, again and again. And then you hate yourself for it.”

Like with drugs, repeatedly giving into the “NOW” urge when we see a delicious-looking cookie or bag of chips weakens our ability to say “LATER.” Eventually we just can’t do it. Lots of people still stigmatize obese people for lacking willpower, but it’s not so simple. And unfortunately, for more and more people who have developed obesity in childhood, their brain reward circuits have already been changed by the time they are old enough to even understand why LATER is better.

Watch Nora’s full talk and let us know in comments if you show the same understanding toward people with obesity that you would toward people who may have drug problems.


Join NIDA Director Nora Volkow, M.D., Thursday, February 12, 2015, at 1 p.m. eastern time for a live Facebook chat to find out what we can learn about food addiction from studying the brain chemistry of people with drug addictions. Tweet your questions in advance using #TEDMED.