Evolution and Cravings for Food
Another example of how evolution has shaped the human mind involves our cravings (see Burnham & Phelan).
Everyone today, has a craving for sweets and fats. And our craving for fats and sweets is very easy to explain from an evolutionary perspective.
As humans were evolving, individuals that craved fats and sweets had an advantage over people who disliked sweet and fatty tasting foods. Liking sweets would have been useful because it prompted people to seek out sweet tasting foods such as fruits and vegetables.
In the past such cravings were useful because fruits and vegetables were (and still are) an important source of many nutrients and vitamins. Hence, individuals who craved sweetness were healthier than those who disliked sweet tasting foods.
Likewise, the same goes for fat. As any dieter knows, one gram of fat contains nine calories instead of the four calories you get from a gram of carbohydrates or protein. Craving fat would have been a useful trait to have in an environment where food supplies were uncertain (i.e., here today and gone tomorrow).
Putting on a little extra weight whenever possible was probably useful when living life as a hunter-gatherer. And, individuals that disliked the taste of fat undoubtedly had a tougher time getting enough calories and were less likely to make it through temporary (and common) food shortages.
But, the problem today, is that while we are the descendants of people who craved fats and sweets, such preferences are no longer useful in our current environment.
Today, people can satisfy their craving for sweets by eating donuts, cake, ice cream, etc., all of which lack any of the nutritional benefits contained in fruits and vegetables.
Likewise, it is possible to find fat everywhere you go from the coffee house, the gas station, the 24 hour convenience store, to any restaurant and grocery store. So, while craving fat made a lot of sense when food was scarce, it makes no sense to crave fat when food is always readily available.
In this case, our evolved preferences are now coming back to haunt us because they are not beneficial to us today.
Unfortunately, it takes tens of thousands of years and numerous generations for evolutionary changes to take place and become the norm. So whether we like it or not, we are stuck with our hunter-gatherer cravings even though many of us live in a society full of food on demand.