The Myth of the Fat Gene

Go Ahead, Drink Bacon Grease for Breakfast

BALTIMORE—Scientists searching for the fat gene, the apparent underlying cause of the U.S. obesity epidemic, should visit Baltimore.  People who have this gene seem to gather at the same locale here each weekend, while those without the gene hang out elsewhere. 

Baltimore is accustomed to life under the watchful eye of scientists.  After all, we were ranked as the fittest city in America earlier this year by Men's Fitness magazine.  This was in their annual "You Got to Be Joking" issue.  Anyone living here will tell you we're a city of unfit misfits. 

But who am I to challenge the scientific integrity of the editors of Men's Fitness?  Perhaps this is just a matter of where you look in the city.

Strange crowds

There was something strange about the crowd this weekend at the Falls Road Running Store, for example.  The shop was having their annual half-day outdoor tent sale, with boxes upon boxes of last year's running shoes stacked high and higgledy-piggledy, selling at a 75-percent discount.  Every runner in the city was there, stocking up on a few pairs to get them through next year.

I couldn't quite put my finger on what was different about this crowd.  The folks were as diverse as Baltimore itself, a mix of classes and ethnic backgrounds.  There were men and women, old and young, long-haired hippies as well as marine-types who part their hair with razor blades.

Finally it hit me.  Unlike two-thirds of America, they were all fit, every single one.  This genetically diverse crowd of runners didn't have the obesity gene.  What were the chances of that?

Quite a different scene was unfolding at Lexington Market a few miles away.  This is the place to go in Baltimore for deep-fried turkey gizzards.  They have a healthy selection of fresh fish, too, which they'll filet and deep-fry for you in a vat of day-old saturated fat and serve with a side of french-fries and two scoops of coleslaw milky white with mayonnaise.  For dessert there is pastry the size of a human foot.

This crowd was nearly entirely overweight or obese.  Everyone seemed to have the obesity gene.  Again, what were the chances of that?

Perhaps genes are directing us either to jog or to frequent Lexington Market.  Or, perhaps genes don't contribute as much to the obesity epidemic in America as some think. 

Clearly there are genetic factors behind weight gain.  Some folks gain weight easily while others don't.  But when 100 percent of the runners are thin and 100 percent of the Lexington Market crowd is fat, it becomes apparent that behavior trumps genes.


The typical adult requires 2,000 to 2,500 calories a day.  Let's look at the junk-food menu.  Raw turkey gizzards contain about 100 calories a piece and carry 50 percent of your daily cholesterol limit.  A platter at Lexington Market comes with about 10 gizzards, deep-fried in batter, and served with fries.  That's easily over half your caloric needs coupled with five times the amount of cholesterol you should consume.  Gene or no gene, how can you remain fit if you eat this kind of food every day?

Or consider McDonald's.  Remember that character Grimace?  You don't see much of him any more in advertisements because people are starting to look like him. 

The much-maligned Big Mac is not the highest-calorie item on the McDonald's menu.  The Crispy Chicken Club Sandwich has 680 calories and 1,830 milligrams of sodium.  With large fries adding 570 more calories and 330 milligrams of sodium, you have consumed over half your daily calories and over 90 percent of the sodium limit in one sitting.

Run an hour, and you'll burn 700-1,000 calories.  It's that simple.


Running, swimming and cross-country skiing are among the most vigorous common exercises.  Unless you live in Norway, skiing is admittedly expensive and elitist.  Swimming often requires membership and can be expensive.  Running requires only a pair of decent shoes.

For a 125-pound person, jogging will burn about 10 calories per minute.  Maybe, for whatever reason, you can't jog.  Walking upstairs will burn about 15 calories per minute.  While there are temptations to consume calories on every corner, there are also countless opportunities to burn calories.  To guide you, there are websites that count calories consumed as well as calculate calories burned.

Imagine if we placed money and effort into searching for the "lung cancer" gene, with the theory that some faulty gene must be responsible for causing cancer in people who smoke a pack a day.  Nonsense.  Stop smoking, and most lung cancer will go away. 

Yes, it is extremely hard to lose weight once you gain it.  And yes, some of us are prone to store fat and gain weight more easily.  Yet, nationwide, fewer deep-fried turkey gizzards and more miles on your feet will put an end to the obesity epidemic.

Christopher Wanjek is the author of the books “Bad Medicine” and “Food At Work.” Got a question about Bad Medicine? Email Wanjek. If it’s really bad, he just might answer it in a future column. Bad Medicine appears each Tuesday on LIveScience.

Christopher Wanjek
Live Science Contributor

Christopher Wanjek is a Live Science contributor and a health and science writer. He is the author of three science books: Spacefarers (2020), Food at Work (2005) and Bad Medicine (2003). His "Food at Work" book and project, concerning workers' health, safety and productivity, was commissioned by the U.N.'s International Labor Organization. For Live Science, Christopher covers public health, nutrition and biology, and he has written extensively for The Washington Post and Sky & Telescope among others, as well as for the NASA Goddard Space Flight Center, where he was a senior writer. Christopher holds a Master of Health degree from Harvard School of Public Health and a degree in journalism from Temple University.