Fats and Sugars – Why We Just Can’t Quit You

by Bradley Miller on September 24, 2009

I read Michael Pollan’s In Defense of Food a couple months ago and it’s really changed the way that I think about and approach food.  In an odd way, I’m actually more willing to spend time shopping and preparing food and it seems to be sticking.  I’m feeling healthier and plan on using it as a foundation for how I think about food – or at least a bit of a start.

However, one fascinating aspect that he didn’t address are the neurobiology and behavior that is created by the food that we eat.  In other words – how does the food we eat affect us neurologically, particularly regarding eating unhealthily as a population.  The brain is relatively straight forward – deep within the brain there are ‘reward’ centers – areas that are responsible for us feeling good after we accomplish something.  These areas light up when we eat, bathe, have sex and are really stimulated by certain recreational drugs – heroin comes to mind.  Interestingly, since heroin stimulates this reward area so much more than food or bathing does, drug addicts often fall in to bodily disrepair because they no longer receive the right reward stimulation.

This is something that I studied while in undergraduate classes at Emory – behavior and its link to the brain reward areas.  Specifically, after reading Pollan’s book I began wondering about different types of food, how they stimulate the body and also stimulate the reward centers in the brain.  For instance, most folks who eat a daily donut, or make a trip to McDonalds every day – they tend to crave that type of food. The more they eat, the more they want to eat.  To take that one step further, I’ve often wondered about the fat and sugar content of foods and whether the amount of fats and sugars in foods are relative to the reward and sensory feedback in the brain.  It made me wonder whether people can actually become addicted to junk food and whether that is one of the problems (not necessarily the problem) that underscores our obesity epidemic.

Some interesting research has been coming out of UT Southwestern in Dallas and the Rudd Center for Food Policy and Research at Yale.  Specifically, I’m thinking directly about research done by Deborah Clegg’s research at UTSouthwestern – her group has shown that saturated fats can cross the blood brain barrier (no real surprise there) and have an effect on the internal workings of our brains and affect satiety.  A great down-to-earth article was written in the NYTimes that captures the essence of her research.  Essentially, her research shows that saturated fats block the effects of Leptin, which is a hormone that works on the brain and make it feel satiated.  And, they showed that those effects can last for days.  In other words, the more saturated fat that you eat, the harder it is for you to feel satiated and therefore the more you eat.  You have to eat more to feel full.  Among the common population this seems counter intuitive – more fat should make you feel full, right? But that’s what is so important about this work – it has the chance to help counter those perceptions.  David Kessler’s appearance on The Colbert Report back in April sums this point up pretty nicely (and humorously), too.

The same can be said about sugars.  Recently, a movement to levy tax on soft drinks has taken flight.  The logic goes like this – the more sugary drinks you eat, the fatter you get, the more you cost the healthcare system.  So, then, why don’t we just tax you for the money that you’re going to coast the system?  I’m not here to debate the merits of this proposed policy, but it’s important to acknowledge that sugary drinks are affecting our population.  Not only that, but diet drinks as well!  A paper in Behavioral Neuroscience illustrates that rats who were given artificial sweeteners tended to actually gain weight.  The same has been shown by UCSD researchers in humans – real sugar actually has a much more profound effect on the brain, causing the person to feel more satiated.  A good, basic article by CBS News illustrates a few more of those points.  Jonah Lehrer also has a great summary on diet soda in his blog The Frontal Cortex.

While I am definitely not blaming our obesity epidemic on these findings or giving people an excuse for why they’re obese, I am saying that we need to better understand the neuro and behavioral implications of this type of research to better address the issues facing this country.  It helps to explain why people have a very hard time staying on diets and staying away from the fatty foods they crave.  This is important as we strive for reform and savings in our healthcare system.  Sugar and pop taxes aren’t the answer, but at least we’re beginning to target a core reason why people have so many health issues, which translates into the massive spending (and economic productivity loss)we see in healthcare.  Without getting people off the bad foods and drinks they consume, we’ll never lose the weight our society so desperately needs to lose.  The argument is much more profound than “just stop eating.”  I’m glad to see that it’s starting to hit the main stream, like in my friend Ramit Sethi’s I Will Teach You to Be Rich blog – “Ugh, why don’t fat people just eat less?” If we want true reforms, we need to better understand why people eat and act the way they do – without understanding this we’re doomed to repeat our mistakes and repeatedly fail.  Real reform has to start at the basics – the way we live our daily lives and what we eat.

{ 1 comment… read it below or add one }

Monica Miller September 24, 2009 at 12:17 pm

In addition to the references you mention, you can’t forget the humorous yet disturbingly disgusting neuro-behavioural “experiment” conducted and documented by Morgan Spurlock in the 2004 blockbuster “Super Size Me” (which you can now watch online in its entirety, here: http://www.youtube.com/watch?v=d7Tv_mihMBA).

Thanks for distilling the arguments, posing the questions – and glad to hear you’re feelin’ healthier these days 🙂

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