Popular Diets: Are Any of Them Right for You? |
 |
by
Doug Kalman MS, RD, FACN
With summer upon us, it's time to shed the weight
that we gained over the winter. Winter weight gain
happens as a result of too many hardy soups and for
others it is simply from a change in the mood that
is a result of shorter days (less exposure to the
sun). Couple this with the constant barrage in newspapers,
or on sweeps week television concerning diets and
the result can be one confused consumer. We hear about
the supposed dangers of the effective Atkins diet,
more about the sensation about the Zone diet and Sarah,
the Duchess of York encouraging people to follow the
Weight Watchers plan. As a health specialist, I am
constantly asked my opinion of the Atkins, Zone and
Weight Watchers plans. With this in mind and knowing
the weight loss is a concern after holiday eating
causes the scale to go in the wrong direction I thought
it best to do a review of each of these diets. This
article will reveal what the current body of literature
says and point you in which diet is right for you
depending upon your motivation and diet needs.
"A" is for Atkins
We all know of the late Dr. Robert Atkins, the warm,
non-confrontational Cornell Medical trained cardiologist.
Dr. Atkins rose to national prominence in 1972 with
the publication and embrace of his first book, “Dr.
Atkins Diet Revolution” published by Bantam
Books. This book shook the seams of the low fat is
best mantra all throughout the New York social circles
and medical practitioners everywhere. People liked
the idea that they could eat meat, red meat and tons
of it while skimping on the rice or bread, but peppering
their foods with natural, creamy butter. However,
some physicians and dietitians decry that the Atkins
approach was a slow nutritional suicide. Who is right?
We still do not know, but what is a fact is that millions
of people have lost weight and enjoy utilizing the
Atkins principles. To learn more if the Atkins Nutritional
Approach™ is correct for you, a brief, but thorough
review is required.
Besides the fact that Dr. Atkins has been on almost
every major talk show, featured in magazines and articles
in various newspapers, one wonders what does the Atkins
Nutritional Approach™ (ANA) really offer? To
learn more, I read some of his books, extensively
viewed the website
and interviewed various staff from the Atkins Research
Foundation. Dr. Atkins believes that his system is
your best bet for improving your energy levels, appearance
and feelings of well being. With this in mind, Dr.
Atkins believes that if you follow his ANA you have
laid the groundwork for a lifetime of better health.
Can it be true? Is this the diet for an exercising
individual or just for the overweight/obese person
looking to shed the extra weight?
The ANA is a four-phase eating plan that is used in
conjunction with vitamin and mineral supplementation
along with regular exercise. We know that exercise
is good for us and we know that almost 90% of the
country does not get all of their needed vitamins
and minerals through foods daily, so is there anything
special about the Atkins plan? In short, yes, but
we will get into the benefits a little later in this
article.
The Four-Phases:
When a person is initiated on the ANA, they are instructed
to restrict all carbohydrates consumption to no more
than 20 grams per day. This is Phase One. The Atkins
staff encourages you to eat all of your carbohydrates
from salad and other non-starchy vegetables. To visualize
what 20 grams of carbohydrate look like, picture 4
teaspoons of table sugar and walla, you have met your
Atkins daily quota of carbohydrates. In actuality,
if you were to eat 20 grams of carbohydrate from just
vegetables, this would approximate out to three cups
per day. Along with eating all of the fish, fowl,
shellfish, meats and eggs along with limited cheese
servings (because of the carbohydrate content), one
can feel full and satisfied quite easily. Dr. Atkins
also notes that you can use healthy cooking oils for
cooking (not frying) as well as for dressings. The
staff warns you to not lose more than a pound per
day on the induction diet. It is also noted that pregnant
or nursing women and those with kidney disease should
not be on this diet.
The Phase Two part of the diet is known as “Ongoing
Weight Loss”. On this Phase, an Atkins dieter
can slowly start adding back in carbohydrate to their
diet. The key word is gradual, as in only five grams
of carbohydrate can be added to the diet weekly until
you reach a weight loss plateau. At the plateau, one
is advised to reduce their carbohydrate intake by
five grams. The question that I have, is what is so
magical about reducing my food intake by 20 calories?
(Carbohydrates are 4 calories per gram).
To better understand the Phase Two aspect of the ANA,
this is where you “find yourself”. This
phase is meant to be used once you have lost 15 or
so pounds or after two-weeks on Phase One, whichever
comes first. Finding yourself means adding back in
wholesome carbohydrates (more vegetables, some fruits,
but absolutely no bread or white rice). This is also
where you can consume more cheeses (regular, cottage
or yogurt style) and you are highly encouraged to
keep a food diary. The goal with a food diary is to
analyze trends, in Atkins case, the good doctor wants
you to become cognizant of how many grams of carbohydrate
you take in and at what gram level do you start gaining
weight back. With the plethora of calorie counting
books out there, finding one as a guidebook or even
using websites such as www.fitday.com
to do your own nutrient analysis becomes very easy.
The third phase (Phase 3) is one where you again increase
your carbohydrate intake, with the very real goal
of making your weight loss slower and more gradual.
Remember while eating meats, fish, shellfish, eggs,
dairy coupled with seeds, nuts, healthy oils, fruits
and nuts and vegetables you have to find out what
ratio of carbohydrate to both proteins and fats is
your magic dial in for mild weight loss and energy
enhancement.
The final phase (Phase 4) is one where you have reached
your goal weight and now are fine-tuning the ANA to
meet the goal of weight maintenance. The Atkins Nutritional
Principals dictate that by following his approach,
you will lose weight, maintain your weight loss, achieve
good health and prevent or reduce your risks of disease.
Sounds like a winner, doesn’t it?
What does the research say?
Our government, while being somewhat concerned with
the country’s collective health, does not always
stay on top of the latest thought in nutritional sciences
for promoting health. In fact, until recently, the
National Institutes of Health has refused to sponsor
any “diet” studies that were not based
on the guidelines of organizations such as the American
Heart Association or the National Cancer Institute.
It was only within the past two years that the NIH
has agreed (due to public pressure) to fund studies
comparing the Atkins Nutritional Approach™ against
the standard nutritional advice for diet and weight
loss. Keep in mind that this occurs for many reasons,
some of these reasons being political and financial
influences by food companies. Take for example the
recent Institute of Medicine (National Academy of
Sciences) report; many members of the IOM were directly
sponsored by the Mars Corporation (as in M&M’s).
While in totality, the IOM report is good for giving
guidelines about how much of each macronutrient; it
also stated that 25% of your carbohydrate intake could
be from sugar. Hmm, I wonder if a certain candy company
influenced that non-scientific recommendation.
In 1999 Dr. Atkins opened a not-for-profit research
foundation (Atkins Foundation). The foundation approves
grants for research and currently is headed up by
Dr. Atkins and consultant, Dr. Abby Bloch. The Atkins
Foundation has currently funded more than five clinical
studies all worthy of review.
The first study ongoing at the Albert Einstein College
of Medicine in New York is open to any person who
follows are controlled carbohydrate diet. This study
is a national registry for weight loss by those who
use the Atkins style approach. It is nicknamed the
“CCARBS” and currently is following 6,088
people. If you follow a controlled carbohydrate diet,
and would like to share your experience contact C.J.
Segal-Isaacson, Ed.D. at the university.
Duke University Medical School also has ongoing studies
comparing the Atkins Nutritional Approach™ to
the American Heart Association Step One diet in overweight
adults with high blood cholesterol issues (risk factors
for heart disease). The first study was recently published
in the American Journal of Medicine. The published
study demonstrated that the Atkins Diet, when followed
as directed led to a ~10% body weight loss over 6
months with a concomitant reduction in blood lipid
levels (cholesterol, LDL and triglyceride). Ninety-five
percent of the participants lost weight and adhered
to controlling carbohydrate intake to 40 grams or
less daily. Another Duke study is pending scientific
publication.
Dr. George Blackburn and colleagues at Beth Israel
Deaconess Hospital in Boston (part of the Harvard
Medical System) is currently conducting an Atkins
funded study. Their study will compare the effects
of the Atkins study to a standard low-fat diet approach
for weight loss and other markers of health. Being
that this study is being done at the prestigious Harvard
School of Public Health, the results, if favorable
to the ANA will receive a lot of press.
Gary Foster, PhD, a behaviorist at the University
of Pennsylvania along with colleagues James Hill of
the University of Colorado and others are conducting
a multisite one-year study also comparing the ANA
to the low-fat, high carbohydrate approach. Results
from the first 6 months were published recently at
the North American Association for the Study of Obesity
(NAASO). Dr. Foster reported that the Atkins group
had more favorable changes in body weight and blood
lipids than the standard recommendations given by
cardiologists.
Jeff Volek, PhD, RD of the University of Connecticut
has published three studies to date and received grants
from the Atkins Foundation. Dr. Volek, a prolific
researcher has tested the ANA in lean healthy people
and in overweight/obese adults as well. The results
of his studies are consistent, the Atkins Nutritional
Approach™ helped with fat loss, weight loss
and the preservation of muscle mass in both lean and
overweight adults. There were also favorable effects
on markers of cardiovascular health. The University
of Connecticut laboratory has also tested the ketogenic
diet and its effect on the ability to do stressful
exercise. The data was not so supportive for the ability
of a low-carbohydrate diet to enhance exercise performance
or duration, but this is not the main purpose or universal
finding of low carbohydrate diets and exercise. It
should be noted that this diet has also been found
to cause an increase in the amount of fat that is
burned during exercise.
Finally, Bonnie Brehm, PhD of the University of Cincinnati
presented results of a study comparing the ANA to
a standard low-fat diet in 53 overweight women for
6 months. The Atkins Foundation did not fund this
study. However, if you understand the ANA versus the
typical low-fat diet, you would not be surprised to
learn that those on the Atkins diet lost significantly
more weight and body fat than the low-fat group. In
fact, the weight loss and fat reduction was almost
double that of the low-fat group. The results were
presented at the national conference of the American
Dietetic Association.
So, is Atkins for you?
My first thought is that anyone who eats according
to the ANA will lose weight. It is pretty simple,
eat vegetables as your main source of carbohydrates,
utilize lean and not so lean meats, fish, shellfish,
poultry, eggs and the like for protein and employ
healthy fats such as nuts, natural seeds and pressed
oils and walla your fat is gone. But, is this diet
doable for life? Yes, you can slowly add some carbohydrate
in the forms of dairy or fruit back into your diet.
But, what happens at holiday time or when there is
a birthday, do you “just say no” to the
high-carbohydrate cake? It is true that the diet when
employed as laid out on the website or even in the
book, Dr. Atkins Age Defying Diet, it can be rather
healthy, however, will it impair your ability to exercise
and exercise hard?
W is for Weight Watchers
Weight Watchers is a program that is more hands on
the either the Atkins Diet or the soon to be reviewed
Zone nutritional plan. Weight Watchers has been around
for 40 years, started on Long Island by Jean Nidetch
in her home in 1963; the company now has classes in
about 30 countries (mostly in the Americas and Europe).
European investment firm Artal Luxembourg owns 94%
of Weight Watchers. (It bought most of H.J. Heinz's
interests in the company). Weight Watchers went public
in November 2001.
From a financial point last quarter, Weight Watchers
attendance in North America was up an impressive 26%,
driving revenue up 23%. This helps explain why analysts
have been bumping up earnings estimates so much. No
one expects those kinds of gains to continue throughout
the year. But it’s a sign all that government
harping about obesity-related health problems, not
to mention a new federal tax deduction for Weight
Watchers fees (in actuality, any physician referred
weight loss plan), may be having an impact.
The
company has also introduced a new “Winning Points”
system that’s popular because it doesn’t
require odd diets. Instead, dieters are given points
for certain types of food and activities and told
to do the math. “Their point system is designed
around the reality that you will do things in your
everyday life like go out to eat and buy your favorite
food in the supermarket,” says Philip Ruedi,
an analyst with T. Rowe Price, which owns Weight Watchers
shares.Weight Watchers most current and widely lauded
program is one where based upon your height and weight
(with your goal weight in mind), you are assigned
a certain point range that you are allowed to eat
daily. Each point corresponds to a combination of
the calorie value of the food along with the fat and
fiber content. This is really an ingenious way of
helping people to watch their fat intake, while being
rewarded for eating high fiber foods. The mantra is
really that no foods are off limits, but eating out
of your point zone is. In fact, if you exercise, you
get to add points to your allotment, if you eat less
than your maximum points you can bank them for the
week. This plus/minus system of points makes it easy
to deal with an upcoming event where you know that
you may eat more than what you should. The new Weight
Watchers system helps the enrollee to maintain a balance
in his or her overall average caloric intake.
Weight Watchers provides (for a fee) food diaries,
point books and checkbook size booklets and meetings
where you can go for support. The system is a good
one, based on understanding that weight is bigger
issues than just what you eat, it can also be what
is eating you and got you overweight to start with.
The Weight Watchers scientific advisors (many medical
doctors, dietitians and obesity researchers) have
helped to craft a plan designed for weight loss of
two pounds per week. While that may not sound like
a lot, we know that the slower you lose weight, the
longer you keep it off. Dr.Winick, the medical director
of Weight Watchers along with others have attempted
to structure what they believe to be a safe program
for lifetime eating and minimizing the risk of developing
any health complications. In essence, the Weight Watchers
program is not about watching or subscribing to a
specific macronutrient ratio for success, but eating
a little less than what you need while striving for
behavioral health and incorporating exercise for long-term
success.
If you do not like meetings, Weight Watchers has set
up an excellent interactive online coaching system
(“Weight Watchers at Home”), which is
marketed more to men than women, but can benefit both
sexes. For additional support, Weight Watchers offers
a magazine, online tracking systems, corporate meetings
(where they set up at your place of business) and
free newsletters which incorporate recipes, news and
tips for success.
Is there published science?
For the past few years Weight Watchers has been giving
out research grants through the American Society for
Nutritional Sciences. Anyone can apply for the grants,
but they are targeted to physician researchers.
In 2001 Michael Lowe, Ph.D. of Hahnemann University
published the results of a phone survey study of participants
of Weight Watcher programs. Dr. Lowe interviewed 1002
people about their weight loss experiences, with 258
face-to-face interviews. The study revealed that five
years after starting the program, 20% were within
5 pounds of their goals weight, ~43% were maintained
a weight loss of at least 5% of their body weight.
Furthermore, 18.8% of the study pool maintained a
weight loss of 10% or more of their body weight. In
short, Dr. Lowe (a consultant to Weight Watchers)
summarized that “the long-term prognosis for
weight maintenance among individuals who reach goal
weight in at least one commercial program (Weight
Watchers) is better than that suggested by existing
research”. In essence, Dr. Lowe found that if
you continue to practice what was successful for you
to start with, your chances for maintaining the weight
loss are very good.
In a study out of the New York Obesity Research Center,
researchers found that those who participated in Weight
Watchers as compared to those following a self-help
weight loss plan were more successful over six-months
at losing weight and improving cardiovascular disease
risk factors. Dr. Xavier Pi-Sunyer, a scientific advisor
to Weight Watchers worked on this study.
Two other published studies have examined the benefit
of the Weight Watchers structured program for obese
breast cancer patients and in people who have experienced
weight gain as a side effect from a medication for
schizophrenia. For most of the readers, these two
applications or scenarios do not fit.
The skinny on Weight Watchers
Weight Watchers is a great plan and program for many,
the question is, will you benefit from it? In reality,
the answer all depends upon commitment to follow the
guidelines and stick with the program. They have set
it up for success, accounting for exercise and even
the occasional indulgence. Depending upon your goal,
this could be the program for you.
If it is Z, than we must cover
The Zone Diet
The Zone diet is one promulgated by Barry Sears, Ph.D.
Dr. Sears, a trained scientist has long believed that
the balance of hormones (glucagon and insulin) were
the key to weight management and health. When the
first Zone book came to press and public awareness,
it garnered in a whole new school of thought for weight
loss. Dr. Sears explained the “hows” and
“whys” of his theories and made biochemistry
and integrated nutrition come alive to the reader.
Millions of people bought his book “Enter the
Zone,” published in 1995 by Regan Books. Now,
millions flock to the www.zoneperfect.com <http://www.zoneperfect.com/>
website. The website does not really explain the diet
per se, but offers recipes, helpful hints, a list
of certified instructors, where you can buy the prepackaged
tasty Zone Perfect meals, bars, shakes and other supplements.
However, viewing the website, one can easily see how
many people become active in the online Zone community.
The Zone Diet is one of 40% carbohydrate (of the low
glycemic variety), 30% protein and 30% fat. Of all
of the diets reviewed herein, this is the one closest
to the recent recommendations by the Institute of
Medicine. According to the staff, food should or can
be viewed as a drug and instead of counting calories
(as many dieters do), we should concentrate on using
food to manipulate insulin levels. Have too high of
insulin levels or many insulin spikes throughout the
day and you will gain weight, fat weight to be precise.
Like the Atkins plan, the Zone Diet utilizes four
keys (Atkins is four phases) in order to Enter the
Zone. The four key elements to the program are 1)
the Zone diet, 2) the use of monounsaturated fats,
3) supplementation with Omega-3 fatty acids and 4)
exercise. The Zone diet asks you to eat mostly lean
protein and natural carbohydrates such as fruit and
fiber rich vegetables. Grains – breads, rice,
pasta and the cereals are a no-no. According to the
Zone website, the diet is designed to feed our genetic
makeup. I do not know about you, but every now and
then, my genetic makeup wants ice cream or even a
corn muffin.
The Zone plan asks you to recall that every meal selection
would begin with protein and that the portion of protein
should be equal to your palm in width and thickness.
The diet also dictates that carbohydrates are either
favorable or unfavorable. If you eat favorable carbos,
you get to have two big fists worth (about 2 cups),
while if you want to eat an unfavorable one, you are
limited to an amount equal to your fist. An example
of unfavorable is pasta, whereas mixed vegetables
are a straight shoot winner. In terms of dietary fat,
Zoners are encourages to add a few nuts, some olive
oil or a couple of olives to balance dietary fat.
If your protein source is high in fat (as in salmon),
you can skip the added fat. The program also asks
you to eat five times per day and to never let more
than five hours pass between a meal or snack. If using
the estimated or eyeball method is not restrictive
enough for you, you can use the “block”
system of nutrient counting also promoted by the Zone
books.
What about published studies?
Interestingly enough, many of the published studies
on the 40/30/30 diet are not sponsored by Dr. Sears
or the Zone Perfect company, but rather the National
Cattleman’s Beef Association (NCBA) or Kraft
(who owns the Balance Bar company).
Recently, Jarvis of Kingston University tested if
one-week in the Zone would have any effect on exercise
performance. Specifically, the research team was attempting
to determine if eating the Zone way could enhance
VO2 max or in time trials (running to exhaustion).
The results found that the diets aids in weight loss
(can be a positive), but had no effect on VO2 max
and a negative effect on aerobic endurance. After
one week in the Zone, the runners were only able to
run 92% of the timed distance that they did previously.
One should keep in mind that one week of any diet
or program is not long enough to really assess if
there is a performance benefit.
A research group from Oklahoma tested three different
diets for 12-weeks in order to see which one was best
for weight loss and retention rates. The data revealed
that all diets (An Atkins like diet, the Zone and
a conventional low-fat diet) caused similar amounts
of weight loss, but the Zone dieting group had the
greatest amount of dropouts. This may have been due
to the detail of sticking to the Zone food prescription.
Dr. Layman’s laboratory has found that the 40/30/30
diet provides a greater anabolic response in the blood
than the standard high carbohydrate diet. His data
can be interpreted as if having to choose a diet;
the 40/30/30 diet at the right caloric value may give
you a better chance for enhanced recovery and muscle
growth when compared to the Food Pyramid recommendations.
This study confirmed findings from the same lab in
2001 (the study was sponsored by both the NCBA and
Kraft). If you couple the Layman studies with one
by Professor Johnston of the Arizona State University
who has found that the 40/30/30 diet causes a greater
amount of post-prandial calories to be burned by the
body, than it is easier to understand why people lose
weight on the Zone diet. The reason is a combination
of the thermogenic effect and greater control of insulin
and anabolic amino acids in the blood.
In another study sponsored by Kraft Foods, Dr. Nancy
Lewis found that a 40/30/30 diet while yet being high
in protein has no deleterious effects on calcium status
thus should not lead to any great concern about bone
health. The study compared the 40/30/30 diet to a
standard high carbohydrate diet.
Since this is a magazine that focuses on active people,
I searched high and low to find a study on the Zone
diet in athletes that was for a time period longer
than one week. Protein researcher Nancy Rodriguez
at the University of Connecticut has conducted a “Zone”
study in runners measuring the effects of a high protein
intake on muscle protein turnover. The Zone diet was
compared to one providing half the amount of protein.
Subjects ate the diet for a preset amount of time
and then were exercise tested after a 75 minute run.
The results strongly indicate that the Zone diet reduced
muscle damage and helped to maintain post-exercise
insulin levels better than a lower protein diet. Thus,
the authors concluded that this diet might be beneficial
for runners.
Two other studies also point out that the higher protein
intake (around 30-40%) were safe for weight trained
athletes and those engaged in aerobic exercise. There
were no negative effects on kidney function or other
markers of health, while those on the Zone like diet
lost more than double the amount of weight then those
on a high carbohydrate diet.
The Zone for Home
Now, with the advent of a microwave, the Zone Perfect
Company offers Zone meals (takes the thinking out
of the equation) as well as bars, shakes and other
goodies. There are also companies that do Zone catering
(such as the Balance Company in Miami) on both coasts
of this great country.
So which diet is for you?
This question is not so simple to answer. My best
answer is, any diet that is one that you can be consistent
with is the one for you. The Atkins diet is great
for inducing weight loss, but menu wise can become
kind of a challenge after the first two months or
so, Weight Watchers is the most complete for dealing
with the emotional and behavioral aspects of weight
control and the Zone is the most time consuming in
order to make your meals balanced by Dr. Sears prescription.
The real answer is to do whichever of these diets
that fit your lifestyle AND does not negatively impact
your exercise performance, mood states and energy
levels. Of course, one can always seek counsel of
a Registered Dietitian (RD) for a more individualized
approach, but that is up to you.
In short, the Atkins diet has not really been tested
in athletes, although one study by Dr. Stephen Phinney
from 20 years ago suggest that it will not negatively
impact performance after the first month. Weight Watchers
was never designed for the athletic person, but the
modern day plan does adjust for this. Weight Watchers
does not stick to a specific macronutrient plan, but
a points system, which means you, can tailor it to
your belief system. Finally, the Zone is well thought
out, but in reality can be a little hard to follow.
Again, the answer is, whichever diet or lifestyle
fits your makeup and personality is the one for you.

Douglas
Kalman MS, RD, FACN is a Director at Miami Research
Associates www.miamiresearch.com,
active in www.sportsnutritionsociety.org
and a consultant to NIKE.
|