The research of Randy J. Sheely, PhD, the recipient of the Outstanding Scientific
Achievement Award at the 2009 American Diabetes Association meeting, tells us that our excess weight goes to our heads. Fat cells talk to our brains.
Humans have evolved to grow and protect those fat cells, but we used to have an on and off switch when it came to appetite. For millions of years we homo sapiens ate when we were hungry, and when we sensed we were full, we stopped. Of course, some of us ate too much or too little now and then, but mostly our brains got the signal from our hypothalamus to regulate our appetite and therefore our food intake. Recently scientists discovered that the hormone leptin was in charge of this function.
So, you're thinking, why can't I just make myself a big pot of Leptin Soup and be done with it?
Well, let's go back 150,000 years to a time when food could be scarce; when a caveperson with tendency to hold onto weight was at an advantage. Appetite was a driving force. Mornings would find hungry, hairy guys gathering around the fire pit. After a strong cup of boiled roots, our ancestors would head off to pursue the kill.
While they were gone, the cavewomen would gather fruits, grubs and berries. As they'd sort the day's harvest, they'd chat about potential mates. The first to be eliminated from the dating pool were any skinny, picky eaters.
If the hunters didn't become prey, the setting sun would find them silhouetted against the orange sky. The tribe would look with ravenous anticipation, as the tired guys would drag in, often empty handed. Root and berry gruel again!
Imagine after nuts and grubs for weeks maybe months on end, a mastodon finally found its way onto the campfire. This was not a one-bite-at-a-time event. Everyone gorged themselves. They were expected to. They sang, danced and flirted; maybe for the next few days, until slight twinges of hunger reminded them it was time to be off pursuing another major meal.
Fast forward to 2012, where a fast-food restaurant sits on every corner; hundreds of kinds of chips tempt us at the convenience store. A root or berry can't compete. And
here we are, the product of natural selection, still programmed to be famine-resistant.
Can we resist? Is this desire for more of a good thing all in our heads? Dr. Sheely tells us, yes. The changes in our diets in recent decades have reprogrammed millions of years of evolutionary advantage.
We feel like we're starving, he explains it's because the high fat foods we often prefer interfere with the signals to our brains. When we've finished the equivalent of a wooly mammoth meal, we still pursue the next delicacy with craving, longing and yearning, as if the survival of our species depended on it. He says this response is not part of our evolutionary direction. Our brain function has actually been altered by what we eat.
Former FDA commissioner David Kessler, takes it a step further and says we are the targets of a food industry campaign. The hunter, the consumer, has become the prey.
In his book, The End of Overeating, he contends that foods containing fat, sugar and salt stimulate the brain to release dopamine, which for humans feels like pleasure. How
about chocolate covered bacon? I saw it at the Ventura County Fair. Yum!
He tells us we feel emotional relief when we eat foods rich in these three. And we create pathways in our brain that make us want more. At the mere thought, we're making a plan. Deprivation only intensifies the desire for the hunt.
Kessler also says that 15% of the caveman's descendants are immune to this planned conditioning by the food industry. He proposes more research to find out why some are so blessed.
Researchers are already trying to find out why some people, even though they have high levels of leptin, are resistant to the effects of their body's beneficial hormone. Heredity
verses environment? Or a little bit of both?
I once heard a story about a woman who was trying desperately to lose weight. At the same restaurant where she would sometimes eat, was another woman. While one
would order salads the other always indulged in a hamburger, fries and a shake. She was annoyingly skinny, clearly a mutation of the evolutionary process.
One day the weight-conscious woman confronted the gorger, "I'm starving myself trying to lose weight. Every time I see you in here, you're eating like this! How do you stay so slim?"
"Well," she dipped her fry in ketchup, "I only do this once a week. It's my reward for eating healthfully the other six days."
An evolutionary idea?