Expert: Dana Krempels, Ph.D. - 5/29/2007

Question
QUESTION: why do foods that are rich in fat tend to be more expensive to buy when compared with carbohydrates?

ANSWER: Dear Kendra,

I'm not sure it's always true that fatty foods are more expensive than carbohydrate-rich foods.  You have only to walk down the snack isle with all those potato chips and pork rinds to find really cheap, really fatty food.

It's also true that fatty meat is much cheaper than lean meat.  

So you might want to examine your premise.  If you can give me specific examples of fat-rich foods that are much more expensive than carb-rich foods, I could comment on those.  But a lot depends on the expense of producing the food, not so much on its fat, carb, or protein content.  So I'd consider that first and foremost.

Hope that helps.

Dana

---------- FOLLOW-UP ----------

QUESTION: We aren't considering junk food...but we would like to know why steak is more expensive than potatoes where steak is the fat and the potato is the carbohydrate.  We are very interested in this question because we are wondering why foods high in fat are usuall more expensive.

Answer
Dear Kendra,

Ah, well if you're comparing steak to potatoes then it's not the fat content that makes the difference in price.  It's the production cost.

Potatoes are from photosynthetic organisms.  All you need to do to produce potatoes is to provide fertilizer, water and space, and voila!  Potatoes.  It's not free to produce them:   fuel and fertilizer are part of the cost.  But in general, it is much less expensive to produce plant crops than animal livestock.

Why?  Consider that you have to feed plants to the livestock.  A cow must eat 10 lbs of corn (or potatoes, if you're a rather unusual farmer) to produce one pound of cow.   So the cost of the steak also reflects the cost of feeding all that feed to the cow--more than ten times what it costs to make a potato.

You might say:  well, but cows eat GRASS, and grass is free!  This might be so, but most cattle are not raised only on grass.  They are fed lots of expensive supplemental grain, and then transported to slaughterhouses, increasing the cost of production because it takes a lot of gasoline to haul cows across the country.

Even if the cow was fed only grass that the rancher doesn't have to pay for (except that he *does*, in the form of mortgage), the market price will still reflect the price charged by meat raised on grain and other foods, and grass-fed meat will be just as expensive because of the market price.

In fact, it might even be *more* expensive these days because of the "glamour effect" of people wanting to be more "green" and be willing to pay more for ecologically friendly foods.

So when you add all that up, the difference in price between steak and potatoes has nothing to do with fat content, and everything to do with how expensive it is to produce per pound.  Or kilo.  Depending on where you live.  :)

Hope that helps.

Dana