While scientific research and theories of evolutionary nutrition are great, I tend to take observation and experimentation above all that. One thing I have carefully observed over the years is my own tendency toward food cravings. What do I crave, when, and why?
I like to visit Gnolls.org from time to time for some interesting perspectives on just this issue. While he offers plenty of facts and references, occasionally I don’t agree with his conclusions. I hate to tear into somebody’s well researched and carefully considered article but where I come from, that’s just what you do. The fact that you don’t agree with everything a person says doesn’t mean you don’t like them, and adore J.S. Stanton I do.
The article in mind is entitled, “Why We Crave Fat”. The hypothesis is that
“animal fat is the primary constituent of the evolutionary human diet.”
The conclusion is that we crave it because we evolved to need it. Additionally, he contends, it is the lack of animal fat in our diets (the lipid hypothesis disaster) that drives us to eat junk food.
He says that
““Low-fat” diets just make us crave fat more keenly—and anti-animal-fat propaganda makes us binge on unsatisfying substitutes.”
Junk Food Is Addictive In Its Own Right
I don’t think it’s so black and white (although, in reality, he probably doesn’t either). We would binge on “unsatisfying substitutes” anyway.
I don’t know about you but I think I may have chosen a bag of Kettle potato chips over a buttered potato once or twice in my life. Junk food definitely has appeal beyond its fat content.
I’m sure all of the Paleo parents out there can attest that, despite the fact that we feed our kids a nutrient dense diet full of meat and animal fat, we still struggle to keep junk out of their mouths. If it were as simple as a need for animal fat our kids would just eat more and more bacon and eggs cooked in plenty of grassfed butter. But they seem to want something else.
Additionally, I don’t necessarily believe that we were designed to crave fat as he suggests.
The Expensive Brain Hypothesis
He goes to admirable lengths to explain that it is precisely the large human brain which requires a move away from fruit and vegetables. He shows that our big “expensive” brains require a whole lot of energy to maintain. This commodity comes at a price, and that price is our gut. With such big brains, we can’t afford to expend the energy on a large gut used to digest plant matter.
This makes sense to me. It is his conclusion that I find troubling.
“Therefore,” he says, “in order to survive on hunted meat, Paleolithic humans had to get the rest of their calories from something besides protein. Dead animals don’t contain significant amounts of carbohydrate …which leaves us with fat.”
He is saying that we had to eat lots of fat to meet our energy requirements because animal flesh doesn’t contain any carbohydrates (and protein doesn’t provide much energy itself).
If we were any other animal I might agree but under the circumstances (i.e. being human) I don’t think it necessarily follows.
What We Really Crave
Let’s return to our big brains for a moment.
It is precisely the curiosity and creativity of the human being that allows us to deviate from what is expected.
We have brains big enough to do something about the lack of available carbohydrates present in animal flesh. As long as 400,000 years ago Homo Erectus controlled fire. God only knows what an average day was like for Homo Erectus but many think he had some time on his hands, time that he easily could have used to dig up starchy, calorie rich edible things.
So, long long ago – long enough to have adapted – we may very well have been eating meat and starch. Quite possibly we were always clever and bored enough to store starchy tubers through the winter (which is actually quite simple) and eat bits of starch throughout the year.
Since we are dealing with intelligent, creative animals the story might not be so simple as ‘I don’t digest plant matter – I eat only meat.’ We’re smarter than that and have been for a long long time.
So why then are we so addicted to junk food? Because we are driven to acquire and eat food for energy; we get energy from fat or from carbohydrates, hence we crave them both.
It is not just fat that we crave. We crave energy. Fat contains energy and carbohydrates contain energy, and quite possibly our nourished bodies and intelligent brains know that the king of energy is the fat/carb combo.
The ultimate craving comes in the form of fat and carbohydrates combined.
Of course this too is heavily laden in theory and may be just as true as anything else you could come up with.
Nevertheless, between this blog (which had 75,000 visits last month), my Facebook page, and my inbox, I have a pretty good sense for which foods people struggle with – the worst seems to be fat and starch combined, not fat all by itself, and not fat with protein.
There are other foods which we crave too: crunchy things, salty foods, sugary foods, dairy, allergens, starch, artificial flavors, MSG, textures made with gums and syrups… These things are all addictive and exciting to eat.
What are you addicted to? Or what foods do you know you must avoid?