HEALTH MATTERS

Promoting health and wellness

Fad diets: Slim on good nutrition

BY JUNE DANIELS, RN, MSN

AMERICANS ARE eating more than and stored carbohydrates that aren’t raise cholesterol levels because of
ever—and it shows. (See Is Your burned for fuel are converted to fat. increased fat and decreased fiber
Patient Overweight?) To shed Limiting carbohydrates means and that these diets increase the
pounds, many overweight people fewer calories are consumed, which risk of heart disease, stroke, and
turn to fad diets designed to help leads to weight loss. Eating lots of diabetes.
them lose a lot of weight fast. Do protein, which tends to be high in High-protein, low-carbohydrate
they work? And more important, fat, makes people feel full so they diets can produce rapid weight loss.
are they safe and nutritionally may eat fewer calories overall. But if a dieter goes back to eating
sound? For answers, let’s evaluate Drawbacks and shortcomings: The carbohydrates, the body turns much
some popular fad diets so you can by-product of protein metabolism is of the food into fat to prepare for
assess the risks and help patients nitrogen. Too much nitrogen excre- another episode of starvation. So
find healthier ways to lose weight. tion can damage the kidneys. people who quit the diet may gain
(See How to Spot a Fad Diet.) Excessive protein intake also can weight more quickly than ever.
boost uric acid production, which • The Sugar Busters’ diet steers
“Get thin quick” schemes can cause gout and kidney stones. dieters away from refined sugars
Promoters of fad diets promise Because these diets are low in car- and other carbohydrates with a high
dieters that they can drop weight bohydrates, they lack some essential glycemic index. Foods with a high
quickly and easily, but their claims nutrients. For instance, they don’t glycemic index raise blood glucose
are rarely supported by respectable have the phytochemicals found in levels quickly and foods with a low
research. You may need to warn fruits and vegetables, which reduce glycemic index raise blood glucose
dieters to be suspicious of diets that the risk of cancer. These diets also levels much more slowly. The theo-
sound too good to be true. Here’s lack vitamins and minerals, and ry is that eating high glycemic index
the skinny on some of the most they pull calcium from bones. foods causes a glucose spike, fol-
popular fad diets, including why The American Heart Association lowed by a big drop in glucose lev-
they may be unsafe. says that these kinds of diets can els that stimulates a craving for
• High-protein, low-carbohydrate more high glycemic index foods,
diets, such as the Atkins diet, are pop- resulting in obesity.
ular and controversial. These diets are Is your patient overweight? This diet calls for consuming 30%
extremely high in fat and offer very Considered the best way to determine
carbohydrates, 30% protein, and 40%
limited food choices because entire obesity, the body mass index (BMI) is a fat. Along with most sugar, banned
food groups, such as fruits and veg- ratio of weight in kilograms to height in foods include white bread, pasta,
etables, may be eliminated. meters squared. So, someone who’s 65 white rice, potatoes, corn, beets, car-
How they work: With these diets, inches tall and weighs 150 pounds has rots, and bananas. Small portions of
ketosis is the key to losing weight— a BMI of 25.8 kg/m2. According to the whole grains are permitted.
but not to healthy nutrition. When American Heart Association, someone How it works: Daily caloric con-
the body is starved of carbohy- with a BMI between 18.5 and 24.9 sumption amounts to about 1,200
drates, it burns its fat stores for fuel kg/m2 is at a healthy weight. Someone calories, so dieters tend to lose
with a BMI between 25 and 29.9 kg/m2
instead of burning glucose. And the weight because they’re eating fewer
is overweight, and someone with a BMI
by-product of fat breakdown is calories.
of 30 kg/m2 or more is obese.
ketones. When excessive ketones Another way to determine obesity is
Drawbacks and shortcomings: This
are produced, the kidneys have to to measure the patient’s waist. Women diet restricts many foods containing
work harder to filter them. The with a waist larger than 35 inches and essential vitamins and minerals.
body goes into starvation mode and men with a waist larger than 40 inches Also, dieters are less likely to stick
metabolism slows down. Then car- have central obesity. with a diet that permits very little
bohydrates are burned more slowly, sugar.

22 Nursing2004, Volume 34, Number 12 www.nursing2004.com

• The Eat Right for Your Type a mostly vegetarian diet with small tients, including the food guide
(ERFYT) diet is based on the theory amounts of protein. People with pyramid and resource guides from
that people should eat certain foods type B or AB blood may eat a varied the Food and Drug Administra-
that are compatible with their blood diet. tion, The National Institutes of
type. The originator of this diet How it works: Only those with Health, and the American Dietetic
claims that when people with cer- type O blood seem to lose weight Association.
tain blood types consume some with the diet, possibly because of • Assess your patient’s eating
foods, substances from the food ketosis as in other high-protein, habits and be alert for clues that
called lectins circulate in the blood- low-carbohydrate diets. she’s following a fad diet. Educate
stream and cause blood cells to Possible drawbacks and shortcom- her about the dangers of fad diets
agglutinate or clot. He thinks that ings: Unless the dieter has type O and urge her to lose weight by
this clotting then causes other prob- blood, the diet doesn’t help with following a nutritionally sound
lems, such as liver and kidney trou- weight loss. The diet for those diet and exercising more.
bles. The ERFYT diet is supposed to with type O blood has the same • If she’s overweight or obese, help
make the dieter healthier by elimi- dangers as other high-protein, her make major lifestyle changes
nating lectins, but this is unsubstan- low-carbohydrate diets. Also, little that will help her keep weight off.
tiated by research. When weight published evidence supports the For example, consult a dietitian
loss occurs, it’s because fewer calo- notion that digested food attacks who can help her plan menus. Dis-
ries are being consumed. and agglutinates blood cells, the cuss the importance of controlling
The diet is further based on the diet’s premise. Because blood from portion sizes and calorie intake.
theory that the earliest people had early man hasn’t been preserved • Help her set realistic weight-loss
type O blood. To adhere to this diet, (and blood types were discovered goals, such as losing a pound or
people with type O blood should eat only in the early 1900s), the claim two a week. Encourage her to join
a high-protein, low-carbohydrate that blood types evolved isn’t sup- a support group. Caution her to be
diet because our caveman ancestors ported by evidence. suspicious of diets that are making
ate mostly meat. Because type A • The Zone diet advocates eating a lot of money for their promoters
blood supposedly evolved next, 40% carbohydrates, 30% protein, and to evaluate their claims care-
people with type A blood should eat and 30% fat. fully. If she has to buy special
How it works: If this diet works, it’s foods, warn her that she’ll probably
probably because the daily caloric regain weight she’s lost when she
intake is low, ranging from 1,000 to goes back to eating regular food.
How to spot a fad diet 1,600 calories/day. • Provide follow-up care to moni-
Any of the following red flags signals Drawbacks and shortcomings: tor her progress and to encourage
bad nutritional advice: Because this low-carbohydrate diet her to continue making healthy
• recommendations that promise fast puts the body into a state of ketosis, choices.
weight loss (more than 2 pounds per it has many of the same drawbacks as June Daniels is a staff nurse at St. Vincent’s Medical
week) the other high-protein diets. As with Center in Jacksonville, Fla.
• claims that sound too good to be
most other fad diets, no scientific
true, such as exercise isn’t needed
studies support this one.
• dramatic statements that are refuted SELECTED WEB SITES
by reputable scientific research or
organizations How you can help American Dietetic Association
Teach patients who want to lose http://www.eatright.org
• recommendations based on a single
“Evaluate the Latest Diets,” WebMD
study, studies published without peer weight to avoid ineffective and po- http://my.webmd.com/content/pages/11/39536.
review, studies that ignore differences tentially dangerous weight-loss htm
from other reputable sources, or sim- schemes, especially if these diets Food and Nutrition Information Center at the
National Agricultural Library
plistic conclusions drawn from a com- are used for more than a couple of http://www.nal.usda.gov/fnic
plex study weeks. Remind them to use com- “Quick-Weight-Loss or Fad Diets,” American
• lists of “good” and “bad” foods mon sense. These interventions can Heart Association
• recommendations that help sell a http://www.americanheart.org/presenter.
help: jhtml?identifier=4584
product.
• Provide available resources. Dis- Last accessed on November 1, 2004.
tribute educational materials to pa-

www.nursing2004.com Nursing2004, December 23