Perceiving the Flavor of Fat

by Julie Terry

When we crave our favorite foods and snacks, those tasty visionsin our heads don't usually resemble that of a large, juicy carrotstick or a sumptuous rice cake. We want fat. It's delicious, it'sfilling, and it just makes everything taste better. It can also makeyou considerably overweight, not to mention the heart disease andother complications that can result if dietary fat is not consumed inmoderation. The appealing taste of fat may very well attribute forthe fact that one in three Americans is overweight ("FDAApproves,"1996). Is there anything that can be done about thisterrible problem that affects us all? Many researchers say there is.You can either choose to face the facts and simply steer clear of thenasty culprit, or you can fool your taste buds into perceiving thetaste of fat without the real stuff ever actually passing your lips.However, before discussing these options, let's talk a little moreabout fat itself and some of the things it's responsible for.

With the large percentage of Americans that are overweight today,it's no surprise that so many physicians are continually recommendingdiet changes to their patients. However, the majority of thesedoctors say that the largest barrier keeping Americans from changingtheir diets is food taste preference (Soltesz, Price, Johnson, &Telljohan, 1994). The patients don't want to switch to a high-fiberlow-fat diet because low-fat high-fiber foods don't taste as good ashigh-fat low-fiber foods. A big bowl of bran flakes just doesn't havethe same calming, pleasurable effects as a big bowl of Blue Bell icecream. Of course, large individual differences must be acknowledged.Some people may actually prefer the taste of bland foods. In fact,one study done on anorexic individuals found that these peopleactually disliked the taste of foods rich in fat (Simon, Bellisle,Monneuse, Samuel-Lajeunesse, et. al. 1993).

Much of what we now know about fat and its effects comes from studiesdone on mice and rats. For example, Rockwood (1990) found that adultrats and developing rats prefer a diet with a relatively high levelof fat. In addition to showing that animals as well as humans preferthe taste of fat, there also appears to be a link between fatconsumption and behavior. Hilakivi-Clarke, Cho, and Onsjafe (1996)uncovered some startling evidence suggesting that a high-fat diet mayinduce aggressive behavior in male mice and rats. A similar study(although conducted on humans) concluded that a low-fathigh-carbohydrate diet is associated with reduction in depression andaggressive hostility (Weidner, 1994). Thus, enjoying and indulging inhigh-fat foods in large quantities on a daily basis may not onlyjeopardize our physical well-being but may jeopardize our mental andemotional health as well.

The actual flavor we perceive once the food is in our mouths resultsfrom a combination of taste and smell to add flavor. The actualperception of tasting works like this: Taste particles are sensed bythe cells that form the taste buds in the tongue. The neuronsassociated with these cells send their taste messages to the brain(Freedman, 1993). When food is placed on the tongue, smell particlestravel to the olfactory neurons through the "back way" called thenasal pharynx which connects the mouth and the inside of the nose(Goldstein,1996). Aromatic chemicals from the food (outside themouth) go by the retronasal route by way of inhaled air to theolfactory neurons (Goldstein, 1996). These neurons have cilia thatcarry receptors for odor molecules. The molecules then bind to theirreceptors and messages are sent along these neurons to the olfactorybulbs at the base of the brain and then to various other parts of thebrain for identification.

So why is it that we enjoy the perceiving the taste of fat so much?After all, it doesn't even constitute one of the four primary tastesof sweet, salty, sour, and bitter. Most likely, genetics have playeda large role in our cravings for such fattening items as nachos andpizza. About 3.5 billion years ago, taste and smell were the mostimportant senses, superior even to vision (Freedman, 1993). Ourancestors had to somehow know if what they were eating was poisonous(bitter), unripe (sour), if it could restore lost sodium andpotassium chlorides (salty), or if it was a high-energy source(sweet). Also, since fat is a great source of energy, and prehistoricman didn't come across it very often, his taste buds taught him tosavor any fat he could get his hands on. However, this has evolvedinto a problem these days, due to the overabundance of fats in ourculture.

What can we do about this endangering health hazard? Certainly wedon't have to become martyrs, hating every minute of our meals as wereluctantly force them down our throats to survive. Part of thesolution to this problem is awareness. Many attempts have been madeacross the nation to increase awareness levels. For example,California has instituted the "Five a Day for Better HealthCampaign," which features a simple, positive, instructive message toeat five servings of fruits and vegetables as a part of a low-fathigh-fiber diet. The campaign appears to have raised public awarenessabout the ability of fruits and vegetables to reduce the risk ofcancer. It also seems to have increased the consumption of fruits andvegetables in major population segments (Foerster, Kizer, DiSogra,& Bal, 1995). However, no matter how much information some peopleare bombarded with and exposed to, it often simply doesn't sink in.People are not interested in being healthy per se. They just want tolose weight and look better and they enjoy the taste of highfat-content foods. Unfortunately, this latter scenario most likelyrepresents the majority of us.

So if awareness doesn't work, what can be done for these individuals?Can anything be accomplished to allow them to enjoy that succulentdouble cheeseburger while maintaining that healthy figure? There justmight be hope for them (us) after all. Not too long ago, the FDAapproved a new fat substitute called olestra to be used in snackfoods and possibly other foods down the road. Olestra is a productthat tastes almost identical to regular fat but without all theactual fat and calories. The reason it tastes like regular fat isthat it is regular fat but without the ability to be absorbed(Institute of Food Science & Technology, 1996). It can be use fordeep frying foods and it's cholesterol free. It almost sounds toogood to be true. Well, the discussion about olestra doesn't exactlyend there. Just like everything in life, there's a flip side to thisstory, too. The major drawback of olestra is that it interferes withthe absorption of vital vitamins such as K, E, D, and A. It alsoinhibits some of the absorption of carotenoids that are believed tooffer some benefits to the immune system. Other cons include a slightaftertaste, possible loose stools, and diarrhea.

If you're not willing to suffer such consequences, there are otherfat substitutes that don't carry the risk of such unpleasant sideeffects. One of these, called Simplesse, is made of whey protein andcan be found in baked goods, sauces, dairy products, frozen desserts,and spreads. Salatrim is another reduced calorie fat, but it cannotbe used to deep-fry foods. Others include Oatrim, Appetize, andvarious fruit and vegetable purees. Although these are all beneficialfat substitutes, olestra is the one to keep an eye out for. It hasbeen, and will continue to be, a major source of controversy in themedical field as well as in the food industry. Meanwhile, we can lookforward to seeing it in fat-free chips from such brands as Pringlesand Frito-Lay("FDA Approves," 1996).

Having said all this, it's all still boils down to individual choice.The individual makes his or her own decisions, including whatquantities of what foods go into his or her mouth and body. Until wehave a satisfactory substitute for the wonderful taste of fat in ourfavorite foods (hopefully without all the physical drawbacks)allowing us to literally "have our cake and eat it too" the endlesscycles of bingeing and denial and gaining and losing will continue.



FDA approves olestra as a fat substitute in snack foods (1996).[On-line]. Available:

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Goldstein, B.G. (1996). Sensation & Perception (4thed.). Brooks/Cole Publishing Company.

Hilakivi-Clarke, L., Cho, E., & Onojafe, I. (1996). High-fat dietinduces aggressive behavior in male mice and rats. Life Sciences,58, 1653-1660.

Institute of Food Science and Technology (1996, September). CurrentHot Topics: Olestra. [On-line]. Available: Rockwood, G.A., &Bhathena, S.J. (1990). High-fat diet preference in developing &adult rats. Physiology and Behavior, 48(1), 79-82.

Simon, Y., Bellisle, F., Monneuse, M., & Samuel-Lajeuness, B.(1993). Taste responsiveness in anorexia nervosa. British Journalof Psychiatry, 162, 244-246.

Soltesz, K., Price, J., Johnson, L., &Telljohan;, S. (1994). Familyphysicians' perceptions of barriers to patients' dietary change. Perceptual and Motor Skills, 78, 968-970.

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