Research at Emory University suggests that if you have a hard time keeping your weight where you want it, there is an oversized organ that has grown too large to let our digestive system adapt to its demands.
“Our evolutionary history has given us a brain that is focused much of the time on eating, and a gut that isn’t designed for today’s variety and volume of high-density food,” explains researcher George Armelagos. He’s a bioarcheologist and an expert in prehistoric diets.
“Our current pattern of eating reflects the way in which Homo sapiens evolved and resolved the omnivore’s dilemma. Our cravings for certain foods don’t go back just a few years, or even 10,000 years, but more than a million years.”
Before agriculture, humans were hunters and gatherers. But as our brains grew larger, making us more intelligent, we became more skilled at finding more food. Eventually, we invented agriculture and gave ourselves an almost never-ending nutrient supply.
At the same time, our oversized brains began demanding more nutrients … yet the food we’ve been feeding ourselves doesn’t have enough nutrients. So we’re craving more and more. Though the brain is about 2 percent of our body weight, it sucks up 20 percent of our calories.
Around 2 million years ago, Armelagos believes, our ancestors’ guts shrank even as our brains grew. “The expensive-tissue hypothesis argues that our big brains are fueled by the energy saved by our having a smaller stomach and shorter large intestines,” he says. “Whatever the reasons for the changes in the alimentary canal, there is no question that they necessitated diets of high-quality, high-density foods.”
Unfortunately, we’re not getting enough foods with high nutrient density. Food companies make calorically dense foods that appeal to our huge brains and overwhelm our mini-digestive systems, but provide little real nutrition (grains are basically nutrient-free).
The end result is obesity.
What’s the solution?
It’s eating nutrient-dense foods that feed the brain without causing the brain to continue to signal us that we’re hungry, which packs on fat.
Snacking on nuts, which have healthy fats, for example, helps in two ways. First, you get lots of nutrients from various nuts and seed-like nuts. Second, you get healthy fats, which send your brain the hormonal signal that you have eaten, and that you’re now full and good to go.
Nutrient-free processed foods have fake fats and don’t send the right signals to the brain, which is why chips and other salty grain-based snacks never seem to satisfy even when your stomach is full.
