0.81 grams of protein, and less than 0.13 grams of total
fat. Grapefruit are rich invitamin C(44 mg),vitamin A
(1187 IU), lycopene (1453 mcg in red and pink varieties),
and potassium (178 mg). Apart from concern about
drug interactions, nutritionists consider grapefruit a
healthful fruit to include in a well-balanced diet. Its
high vitamin C content helps to protect against scurvy,
while the lycopene contained in red and pink varieties
is an antioxidant thought to slow down the aging of skin
and connective tissue. Lycopene may also be important
in preventing chronic diseases such as heart disease and
prostatecancer. In addition, the fiber content of grape-
fruit is helpful in preventing constipation.
Evaluations of grapefruit in weight
reduction diets
Grapefruit is considered a good food choice for
people watching their weight because it is relatively
filling thanks to its fiber content. It also has a low
glycemic index (GI), which is a measurement of the
rate at which carbohydrates in the food affect a per-
son’s blood glucose level within two hours after eating
the food. Foods with low GI scores break down slowly
in the digestive tract and thus prevent sudden changes
in the blood sugar level—an important consideration
for persons with metabolic syndrome or type 2 diabe-
tes and possibly for those watching their weight for
other reasons. Grapefruit has a GI of 25 (pure sugar is
100), which is lower than the GI scores of apples (40),
oranges (51), and bananas (51).
According to the research team at Scripps Clinic, it
is not yet known as of 2007 why grapefruit appears to
improve insulin response in overweight people or why it
assists weight loss. Ongoing research may help to answer
this question, but one finding at least is clear: grapefruit
does not contain any miracle fat-burning enzymes.
Resources
BOOKS
Dunford, Randall EarlThe Grapefruit and Apple Cider Vin-
egar Combo Diet. McKinney, TX: The Magni Com-
pany, 2002.
Scales, Mary Josephine.Diets in a Nutshell: A Definitive
Guide on Diets from A to Z. Clifton, VA: Apex Pub-
lishers, 2005.
Thompson, Daryl L., and M. Joseph Ahrens.The Grapefruit
Solution: Lower Your Cholesterol, Lose Weight and
Achieve OPtimal Health with Nature’s Wonder Fruit.
n.p.: Linx Corporation, 2004.
PERIODICALS
Bakalar, Nicholas. ‘‘Experts Reveal the Secret Powers of
Grapefruit Juice.’’New York Times, March 21, 2006.
Available online at http://www.nytimes.com/ (accessed
March 20, 2007).
Cunningham, E., and W. Marcason. ‘‘Is It Possible to Burn
Calories by Eating Grapefruit or Vinegar?’’Journal of
the American Dietetic Association101 (October 2001):
1198.
Doheny, Kathleen. ‘‘Grapefruit Lowers Weight, Fights
Cancer.’’Drug Digest, August 25, 2004. Available
online at http://www.drugdigest.org/DD/Articles/
News/0,10141,520829,00.html (accessed March 20,
2007).
Fujioka, K., F. Greenway, J. Sheard, and Y. Ying. ‘‘The
Effects of Grapefruit on Weight and Insulin Resistance:
Relationship to the Metabolic Syndrome.’’Journal of
Medicinal Food9 (Spring 2006): 49–54.
‘‘Grapefruit and Weight Loss.’’Medical News Today, Jan-
uary 24, 2004. Available online at http://www.medical-
newstoday.com/medicalnews.php?newsid=5495
(accessed March 20, 2007).
OTHER
American Dietetic Association (ADA).Fad Diet Timeline—
Fad Diets throughout the Years. Press release, February
1, 2007. Available online at http://www.eatright.org/
cps/rde/xchg/ada/hs.xsl/media_11092_ENU_HTML
.htm.
Enbysk, Liz. ‘‘It’s NOT Your Grandma’s Grapefruit
Diet.’’MSN Health and Fitness, n.d. Available online
at http://health.msn.com/dietfitness/articlepage.aspx?
cp-documentid=100096310 (accessed March 20, 2007).
Mayo Clinic.Mayo Clinic Diet—Myth vs. Reality. Available
online at http://www.mayoclinic.org/healthinfo/
mayoclinicdiet.html (accessed March 21, 2007).
U.S. Department of Agriculture (USDA), Agricultural
Research Service.USDA National Nutrient Database
for Standard Reference, Release 18. Available online
at http://www.nal.usda.gov/fnic/foodcomp/Data/
SR18/sr18.html.
ORGANIZATIONS
American Dietetic Association (ADA). 120 South Riverside
Plaza, Suite 2000, Chicago, IL 60606-6995. Telephone:
(800): 877-1600. Website: http://www.eatright.org.
Dietitians of Canada/Les die ́te ́tistes du Canada (DC). 480
University Avenue, Suite 604, Toronto, Ontario,
Canada M5G 1V2. Telephone: (416) 596-0857.
Website: http://www.dietitians.ca.
Grapefruit Pectin Diet Tablets. [No other contact informa-
tion] Website: http://ordertron.stores.yahoo.net/
grdipl.html (accessed March 21, 2007).
Grapefruit Solution Dietary Supplement. [No other contact
information] Website: http://www.grapefruitsolution
.com/index.asp (accessed March 21, 2007).
National Institutes of Health, Office of Dietary Supplements
(ODS). 6100 Executive Blvd., Room 3B01, MSC 7517,
Bethesda, MD 20892-7517. Telephone: (301) 435-2920.
Website: http://dietary-supplements.info.nih.gov/
index.aspx.
Scripps Clinic, Department of Nutrition and Metabolic
Research. 12395 El Camino Real Street, 317, S95, SanGrapefruit diet