balanced, moderately calorie-reduced diets. The most
common three-day diet requires dieters to eat only
about 1,000 calories a day, with some versions that
have been analyzed consisting of at as few as 700
calories per day. This is too few for most people to
maintain good health. A diet that contains fewer than
800 calories per day is considered a very low calorie
diet. Very low calorie diets carry high risks of side
effects, such asgallstonesand cardiovascular prob-
lems. Very low calorie diets are only intended for the
extremely obese who are experiencing significant med-
ical problems due toobesity. These diets are carried
out under the close supervision of physicians. They are
not intended, or safe for, dieters to follow on their
own.
Dieters who follow a three-day diet may find that
any weight lost is gained back as soon as the diet is
over, and may even find that more weight is gained
that was lost. Having a very low caloric intake makes
the dieter’s metabolism slow down because the body
thinks that it is starving. Then when a normal number
of calories are reintroduced into the diet, the body
wants to store extra fat in case there is a period of
starvation again. This natural defense mechanism of
the body against starvation can cause dieters who
alternatively eat very few calories and then return to
normal eating to gain large amounts of fat over time,
even while they are trying to diet. Very low calorie
diets pursued over only a few days also promote
binge eatingat the end of the diet.
Many of the versions of three-day diets, especially
those intended for fasting, carry a high risk of vitamin
and mineral deficiency. The body needs food from
each of the food groups every day for good health.
Drinking only fruit juices, or eating any very limited
variety of foods, can make it nearly impossible for a
dieter to get all of the nutrients required for good
health. Any dieter considering this kind of diet should
consult a physician about an appropriate multivitamin
or supplement to help reduce this risk of deficiency.
Multivitamins anddietary supplements carry their
own risks, and can not replace a healthy, well-
balanced diet.Research and general acceptance
Three-day diets are not generally accepted as
healthy, effective ways to lose weight for the long
term. Although no scientific studies have been carried
out to determine the effectiveness of common three-
day diets, experts suggest that anything that promises
dieters 10 lb (4.5 kg) of weight loss in three days is
unlikely to be taking off fat. Instead, dieters are prob-
ably losing water weight, with possibly a little fat loss
and some muscle mass loss through the reduced calo-
ric intake.
The United States Department of Agriculture
makesrecommendations fora healthydietinits MyPyr-
amid food guidelines. MyPyramid gives recommenda-
tions about how many servings of each food group are
required daily for good health. These recommendations
can be found at<http://www.MyPyramid.gov.>Any
diet that will produce sustainable, healthy weight loss
should follow these guidelines and include foods from
each food group every day. Sustainable diets should not
be extremely restrictive of any food group, or be
extremely calorie-reduced.
Many studies have shown that exercise and diet
are more effective at producing weight loss when done
together than either is done alone. Three-day diets do
not usually have any exercise recommendations.
Instead, they generally claim that a combination of
foods will magically melt away fat without the dieter
having to expend any effort. Healthy weight loss plans
should include both a diet and an exercise component.
As of 2007, the Centers for Disease Control recom-
mended that adults get a minimum of 30 minutes of
light to moderate exercise each day for good health.Resources
BOOKS
Shannon, Joyce Brennfleck ed.Diet and Nutrition Source-
book. Detroit, MI: Omnigraphics, 2006.
Willis, Alicia P. ed.Diet Therapy Research Trends. New
York: Nova Science, 2007.
ORGANIZATIONS
American Dietetic Association. 120 South Riverside Plaza,
Suite 2000, Chicago, Illinois 60606-6995. Telephone:
(800) 877-1600. Website:<http://www.eatright.org>QUESTIONS TO ASK THE
DOCTOR Is this diet safe for me?
Is this diet the best diet to meet my goals?
Do I have any dietary requirements this diet
might not meet?
Would a multivitamin or other dietary
supplement be appropriate for me if I were to
begin this diet?
Is it safe for me to follow this diet over an
extended period of time?
Are there any sign or symptoms that might
indicate a problem while on this diet?3-day diet