Shape Up America! Newsletter
Preventing Childhood Obesity: Vigorous Physical Activity—YES, Restricting Calories—NO*
by Bernard Gutin, PhD
My colleagues and I at the Medical College of
Georgia investigated the relationship among
diet, physical activity and body composition
in 661 African American and white adolescents
ages 14 to 18.1 We hypothesized
that fatter youths would have higher levels
of energy
intake and lower levels of both moderate and
vigorous physical activity.
To our surprise, we found that higher levels
of percent body fat were associated
with lower levels of energy intake and
lower
levels of vigorous (but not moderate)
physical activity. Youths who did the most
vigorous physical activity and
consumed the
most calories were the leanest. Those
who did
no vigorous physical activity had a percent
body fat of
28.6 and consumed 1744 calories a day, while
those who did at least 1 hour of vigorous
physical activity each day had a percent body
fat of 19.4
and consumed 2203 calories a day. See
Relationship
of Vigorous Physical Activity, Caloric Intake
and Percent Body Fat.
Although moderate physical activity, such as
brisk walking, burns calories, we found that
lower percent body fat was linked to greater
amounts of vigorous, but not to moderate,
physical activity. Vigorous activity includes
sports, games and dance activities such as
running, swimming, soccer and aerobic
dancing. These activities impart a
significant "mechanical load," which means
they work your body's muscles and bones. This
type of activity stimulates stem cells to
differentiate into bone and muscle rather
than fat.2 A healthy body
composition in
youths requires both a large amount of
vigorous physical activity and ingestion of
sufficient calories and nutrients to support
this tissue-building process.
This idea is further supported by
experimental studies that looked at the
effect of mostly vigorous physical activity,
without restriction of calories, on body
composition. Research on youths with varying
levels of fatness and fitness found moderate
physical activity to be ineffective in
preventing obesity, so we conducted studies
using 300 to 400 minutes a week of mostly
vigorous physical activity and found positive
effects on body composition, including
reduction of visceral adipose tissue (the fat
around abdominal organs). Within the
intervention groups, those youths who
participated regularly and maintained the
highest heart rates during the physical
activity sessions showed the greatest
decreases in percent body fat and the
greatest increases
in bone density.3,4
Youths who are obese and unfit can benefit
from exercise of relatively low intensity and
duration. For example, in obese youths,
studies using 155 to 180 minutes per week of
physical activity at moderate to high
intensity produced favorable reductions of
percent body fat and visceral adipose tissue
and increases
in bone density and aerobic
fitness.5 As
children improve in fitness, they should be
encouraged to progress to higher amounts and
intensities of physical activity.
An expert consensus panel has suggested that
youths engage in at least 420 minutes a week
(about 60 minutes a day) of moderate to
vigorous physical activity.6 The
research
reviewed here suggests that greater emphasis
should be given to vigorous rather than
moderate physical activity.
Taken together, these findings suggest that a
paradigm shift is needed to improve the
effectiveness of pediatric obesity prevention
interventions. It is well known that eating a
nutritious diet supports the development of
muscles and bone and other aspects of proper
growth and development, as well as good
health. However, limiting energy intake runs
counter to the biologic demands of growth,
which require adequate calories and
nutrients. When youths engage in adequate
amounts of vigorous physical activity,
calories and nutrients are preferentially
directed to the production of lean tissue
(muscle and bone) rather than fat. So,
insuring a high quality diet and plenty of
exercise, rather than calorie restriction, is
the model to pursue to prevent obesity and
improve body composition.
* A longer version of this editorial will
soon appear as a Perspective article in the
journal Obesity.
Bernard (Bob) Gutin, PhD, is Adjunct
Professor of Nutrition at University of North
Carolina in Chapel Hill and Professor
Emeritus at Teachers College of Columbia
University and the Medical College of
Georgia.
Triceps — Part III (Chair Dips)
by Michael Roussell
This month we continue our focus on the
triceps muscle of the upper arm. The triceps
muscle makes up almost 2/3 of the upper arm;
the other muscle in the upper arm is the
biceps. If you are just beginning to work on
your triceps, we suggest that you review Part
I and Part
II of the upper arm series before moving
on to this more difficult exercise.
The triceps muscle is often used with the
chest and shoulder muscles in a pushing
movement. The push up, for example, is a
pushing movement. Here, we are going to look
at several variations of the bench (or chair)
dips, which specifically work the triceps.
To perform bench dips, you will need a sturdy
bench that is placed against a wall so that
it cannot slip while you perform this
exercise. A chair can also be used for this
exercise, but my chair is too narrow to allow
me to sit on the edge and at the same time
grip the front edge of the chair. So I put
two chairs together as shown in the picture
below. If you don't have a bench, grab a
second chair and place them side by side
against a wall.
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For safety's sake, position the chairs right
next to each other and back them up to a wall
to insure they will not slip or move as you
perform this exercise.
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There are two different variations of this
exercise, one with your legs bent, which is
the beginner position, and another with your
legs straight, which is more advanced. To
start this movement, you will need to sit on
the very edge of the bench and place both
hands on the front edge of the bench on
either side of your body. Place your hands so
your entire palms are on the bench and your
fingers are gripping the edge firmly. Next,
place your feet together in front of you so
that your knees are bent and your feet are
flat on the ground. Now you are ready to
start the movement.
Slide your rear end off the bench so now only
your arms are holding you up. With your
elbows pointing backwards, slowly bend your
arms and lower your bottom toward the
ground—just far enough so that a right
angle
forms at your elbow joint. Stop at that point
and reverse the movement, pushing your hands
into the bench and straightening out your
arms. When you reach the top of the movement,
stop just before you lock your elbows; this
will keep your triceps working for the entire
movement.
It's important to keep your neck strong
as you perform this exercise. Don't let your
head go forward, especially when you are in
the downward position. Keep your ears
positioned squarely over your shoulders for
the entire movement.
This movement is very simple but as you will
soon see, very effective. To make it more
difficult, straighten your legs and stretch
them out before you so that only your heels
are touching the ground.

Repeat the exercise until you reach the
recommended number of sets and reps
(repetitions). This will vary depending on
your fitness level, as shown below. Perform
this exercise once or twice a week.
| LEVEL |
SETS/REPS |
COMMENTS |
| Beginner |
1 set of 10-12 reps |
Legs are bent |
| Intermediate |
2 sets of 10-12 reps |
Start with legs bent; after 2-3 months,
straighten legs |
| Advanced |
3 sets of 10-12 reps |
Legs are straight |
Note: When you move up a level, you may find
it difficult to complete all the reps. That's
okay. Go as far as you can and try to add 1
or 2 more reps each workout.
International Walk to School Day
Now is the time to start planning for
International Walk to School Day 2008. On
October 8 and throughout the month, millions
of children around the world will walk or
bike to school for a purpose—to promote the
health benefits of physical activity, the need
for safe places to walk and bike, and concern
for the environment. Now in its twelfth year
in the US, International Walk to School Day
involves nearly 6,000 schools from all 50
states. In 2007, a record 42 countries
participated in International Walk to School
events.
Children, parents, teachers and community
leaders are encouraged to join together for a
day, week or month of walking. Go to
International
Walk to School Day 2008 for more
information and tips on how to organize,
promote and register for International Walk
to School events.
Menus for Weight Loss and Healthy Eating
Shape Up America! offers these simple,
convenient 1500
calorie and 2000
calorie menus to help
you eat healthfully while controlling your
calories. If you have any suggestions or
comments, feel free to e-mail us at
newsletter@shapeup.org.
My Story
A medical scare led Gena to slowly and
realistically
change her poor eating habits into good ones
and to teach her fellow students how to lose
weight in a healthy way.
Like many of you who are reading this story,
I have struggled with losing weight most of
my adult life. I have tried all the popular
diets and a few crazy ones, too. By the time
I was 35, I came to the conclusion that I was
going to be fat the rest of my life. I always
thought of my weight in terms of appearance,
but that all changed when I had a TIA, or
small stroke, at age 35 and 279 lbs. on a
5'9" frame. I didn't think I could die from
being overweight. That is when I started to
research "what does my body need to be healthy?"
Like gasoline in your car, the food we use to
fuel our body determines how it will run. I
started slowly going from a bad habit, to
another bad habit that's not as bad, to
another bad habit that's not so bad, till I
started to reach good habits. This allowed me
to make new healthy habits that took hold,
and without feeling deprived. Read
More…
If you would like to share your personal
success story and be an inspiration to others
who desire to lose weight, simply use our story
submission system on the SUA Web site.
Recipe of the Month
This fun-to-make snack or dessert is a great way to fit more fruit into your diet. Each kebab is low in fat, high in vitamin C, and a good source of fiber.
Grape Kebabs
Makes 4 servings, 1 kebab per serving
INGREDIENTS:
- 4 four-inch bamboo skewers
- 1 cup chopped pineapple
- 1/4 cup apple juice
- 1/4 cup nonfat plain yogurt
- 2 small bananas, cut into 1/2-inch thick
slices
- 1 Tbsp. orange juice
- 2 kiwifruits, peeled and cut into
1/2-inch thick slices
- 1 cup purple seedless grapes
- 1/3 cup small strawberries
- 1/3 cup melon balls
- 1/3 cup blackberries
DIRECTIONS:
- For the dip, in a small saucepan bring
the pineapple and apple juice to a boil.
Reduce the heat, cover and simmer for 10
minutes, stirring occasionally. Let stand
about 25 minutes or until cool.
- Transfer the pineapple mixture to a
blender or food processor. Add the yogurt and
blend or process until smooth. If desired,
cover and chill in the refrigerator before
serving.
- Place the bananas in a small bowl.
Drizzle with the orange juice, then gently
toss until coated.
- Cut the kiwi slices into quarters.
- For the kebabs, thread the grapes,
bananas, kiwi, strawberries, melon balls and
blackberries onto 4-inch bamboo skewers.
Serve with the dip.
Nutritional analysis per serving: 150
calories, 1 gram total fat, 0 grams saturated
fat, 0 grams trans fat, 36 grams
carbohydrate, 3 grams protein, 4 grams
dietary fiber, 20 milligrams sodium, 75
milligrams vitamin C
Source: Fruits
and Veggies More Matters™
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Editor: Adrienne Forman, MS, RD
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