How much should I weigh?
A lot of us get really hung up on that
number on the scale. But weight doesn’t tell you much about your
health and fitness status, or even how you look! A crucial part of
determining how much you should weigh has to do with what makes up
that weight. For example, is your weight made up of a healthy ratio
of muscle, bone, and fat? Knowing this can help you interpret your
|A lower body weight is not
necessarily the goal to improve your health or enhance your
appearance. Have you ever heard it said that muscle weighs
more than fat? What that means is that muscle is more dense
than fat. A pound of muscle weighs the same as a pound of
fat, but muscle mass is more compact and only takes up 1/3
the space! If you go on a healthy weight loss program, which
includes regular exercise, you will almost certainly gain
muscle and lose fat. The scale may stay the same or may even
go up, but you lose inches, since muscle takes up less
Read on to learn…
- How to calculate your Body Mass Index.
- What body fat percentage should you have?
- What is your body type, and how does your body type
affect your weight goals?
- Is the media's "ideal body" realistic, or even
healthy, for you?
- What can you do to achieve your personal best?
|Did you know…
If you looked only at the weights and heights of a
sample of Division I college football linemen, 80%
would be classified as “morbidly obese!” But their
percent of body fat is relatively low. Their
“excess” weight is mostly muscle and large bones.
Likewise, if you look at the muscle
to fat ratio of a sample of “normal” or
“underweight” college women (who sometimes eat
restrictive diets), you find that many of them have
very slow metabolisms, partially because of a low
muscles mass, and are actually carrying more fat
Body Mass Index
The body mass index (BMI) is a screening tool to assess weight
status. You can use the calculation below to determine your BMI.
Keep in mind that BMI is only based on height and weight; it does
not take into consideration your body composition or genetics. A
healthy weight for you may be higher than the BMI standards. Your
eating habits, physical activity patterns, other lifestyle choices,
body composition, and genetics are more important than any number on
the scale in determining what weight is right for you. Use BMI as a
rough indicator, and consult a health professional to help you
determine what weight is right for you.
How do you calculate BMI?
BMI is calculated by the following formula: weight in kg / height in
m2. If you're not familiar with kilogram and meter measurements,
follow the steps below to calculate your BMI.
Step 1. Take your weight (in pounds) x 703
Step 2. Divide that number by your height (in inches)
Step 3: Divide that number by your height (in inches) again
Example: Woman who is 5’3” and weighs 135 lb.
Step 1. 135 lb. x 703 = 94,905
Step 2. 94,905 / 63” = 1506
Step 3. 1506 / 63” = 23.9
BMI = 23.9
Underweight < 18.5
Healthy weight 18.5-24.9
Obese I 30.0-34.9
Obese II 35.0-39.9
Obese III 40+
Body composition is a better indicator of your health and fitness
status than body weight, but it is still not perfect. Your genes
determine your body type. Some body types carry more fat than
others--no matter what you eat or how much you exercise. Percent
body fat does not necessarily tell you how healthy or fit you are,
or tell you how you look. There are large-framed students who have a
higher percentage of body fat who train for triathlons, exercising
several times a week and eating a healthy balanced diet. Other
students may be ultra-thin and have a lower percentage of body fat,
but don’t consume adequate calories or nutrients, lack physical
endurance and strength, and don’t look healthy or fit.
Unlike BMI, there is no one universally accepted set of body fat
standards. As a result, you may see many different reference ranges
from various fitness organizations, fitness magazines, and gyms. Not
all of these reference ranges are based on research or take into
account such things as genetics. As a result, many ranges are too
narrow to reflect the diversity of healthy and fit bodies. A normal
and healthy percentage of body fat varies substantially, and charts
and graphs should not be regarded as the “end-all-be-all” of what is
healthy and normal for you personally.
Body Fat Standards
The American College of Sport’s Medicine developed the following
reference ranges based on research.
|High Risk *
“Health standards” reflect the
percent of body fat that generally does not increase your risk
for health problems. Excessive body fat, especially around the
abdomen, can increase your risk for high blood pressure,
diabetes, osteoarthritis, and heart disease. Young men who have
greater than 22% body fat and young women who have greater than
35% body fat may be at greater risk for these health problems,
independent of their eating, activity, and other lifestyle
“Fitness standards” reflect the
percent of body fat that generally results from greater physical
training. A greater percentage of muscle and lower percentage of
fat may improve strength, speed, endurance, and agility.
However, dropping below 16% body fat for women and 5% body fat
for men DOES NOT further increase your athletic performance or
level of fitness. Instead, too low body fat can actually impair
your physical health and performance. Men and women need a
certain amount of body fat to insulate vital organs, regulate
body temperature, and ensure adequate production of sex
hormones. In particular, women who restrict calories and
exercise excessively may have a very low percentage of body fat
and consequently have very low estrogen levels and stop
menstruating. Because estrogen keeps women’s bones strong, women
who stop menstruating are at much greater risk for stress
fractures and a debilitating bone-thinning disease called
How do you measure body fat?
There are many methods for determining body composition, including
skin fold measures, bioelectrical impedance, and underwater
Which method is best? The accuracy of each method can be highly
variable depending on the skill of the person doing the measurement,
whether the person being measured is well hydrated or dehydrated,
how good the equipment is, and/or the reference tables used. Even
the best techniques have an error of at least 3%, plus or minus.
That means that if your body fat is tested at 20%, it could really
be anywhere between 17 and 23%. You can get one reading today and a
different one tomorrow.
To accurately monitor changes in body fat over time, be sure to use
the same technique with the same person under the same conditions
each time you take a measurement. If you switch to a different
technique, you may get different results for any number of reasons
having nothing to do with real changes in your body composition. It
takes several months to see any true changes in body composition, so
there’s no need to repeat testing more than once every 3 months.
Each one of us inherits a specific body type. Even though the media
would have us think otherwise, there are really many healthy and
normal body types. For ease of reference, body types have been
categorized into three main types, and those types have been further
categorized as blends of the three main types. Each body type has
advantages over the others for certain activities, but a person with
any body type can be healthy and fit and look great!
Ectomorphs are generally tall and thin and have long arms and legs.
These people have difficulty gaining weight and muscle no matter how
much they eat or how hard they weight train. They have the body type
you tend to see in ballet dancers, runway models, long-distance
runners, and basketball players. A very small proportion of the
population has this type of body.
Mesomorphs are generally muscular, shorter, and have stocky arms and
legs. These people are strong and tend to gain muscle mass when they
do strength training. They may find it difficult to lose weight, but
they excel in power sports like soccer, softball, vaulting in
gymnastics, sprinting events in track and field.
Endomorphs are generally shaped like apples or pears and carry more
body fat. Their bodies resist losing weight and body fat no matter
how restrictive they are with their eating. In fact, the more they
“diet,” the more their metabolisms slow down to resist weight loss.
These people are better able to handle long periods of starvation
and famine (which was a benefit to our ancestors). Sports they excel
at are distance swimming, field events, and weight lifting.
If you don’t think you fit into any of these, don’t worry. Many of
us fall somewhere in between. The important thing to know is that
there are many body types, and all of these types are normal.
The Media’s “Ideal” Body
The media sets unrealistic standards for what body weight and
appearance is considered desirable.
Young girls believe that Barbie is how a woman is supposed to look
(i.e. no fat anywhere on your body, but large breasts). But, if
Barbie were a real person, she would be 5’9” tall and weigh 110
pounds, only 76% of her healthy weight. Her measurements would be
39-18-33, and she likely would not be able to menstruate due to
Similarly, young boys are given the impression that men are supposed
to have muscles bulging all over their bodies. Take a look at their
plastic action-figures like GI Joe Extreme. If GI Joe Extreme were
life-size, he would have a 55 inch chest and a 27 inch bicep. In
other words, his bicep would be almost as big as his waist and
bigger than most competitive body builders.’
The media’s portrayal of what is desirable and normal keeps getting
thinner and thinner for women and more muscular and cut for men. For
example, 25 yrs. ago the average female model weighed 8% less than
the average American woman. Currently, the average female model
weighs 23% less than the average American woman. Similar trends are
being seen with men. In the past 25 years, the average playgirl
centerfold man has shed about 12 lbs. of fat, while putting on
approximately 27 lb. of muscle.
In reality, only about 5-10% of women have the ultra-long and thin,
model body-type. Yet that is often what most women aspire to be.
Similarly, boys see a body ideal that is impossible to achieve
without resorting to extreme measures such as taking anabolic
steroids. There is a physiologically limit to how much muscle a
man’s body can attain naturally, given his height and body fat
percentage, just as there is a limit to how thin a woman can look
due to her body type.
Another thing to keep in mind is that physical attractiveness is
about more than body shape and size. It also matters how you present
yourself (sometimes a good hair cut or bright smile can make a big
difference), or if you are a fun person to be with, just as
examples. People who come across as too perfect are often
intimidating. It’s important to know that you can do other things to
improve your appearance without focusing exclusively on your body
shape and size.
What can you do to achieve your personal best?
Realize that you cannot change your body type, and try not to
compare yourself to others. You are who you are, and no one else can
Invest time and money in yourself in ways that make you feel your
best. Examples include getting a manicure or massage, buying new
clothes or fitness equipment (like walking shoes, gym bag,
resistance bands, free weights, etc.), enrolling in a yoga, dance,
or martial arts class. Avoid spending money on diet products.
If you weigh yourself, only do so once a week, and be sure to
choose the same time of day and wear the same amount of clothes each
time. It’s normal for weight to fluctuate by a couple of pounds (up
or down) daily or even at different times in the same day, due to
fluid shifts or how much you’ve recently eaten, drunk, perspired, or
gone to the bathroom. If you feel the need to measure your body fat
percentage, only do so once every 3 months. Choose the same method
and measurer, and remember that there is at least a 3% margin of
error with even the best methods.
Learn to fuel your body for optimal energy, fitness, and health!
Enroll in a nutrition class or read the other sections of this web
site to find out how well your current eating plan meets your needs.
Move and enjoy your body, not because you have to, but because it
makes you feel good! Go for a walk, a swim, or a bike ride, or dance
to boost your energy, mood, and cardiovascular health. Do yoga, tai
chi, or stretching to relax and improve your flexibility. Use
weights, resistance bands, or your own body weight to build muscular
strength and endurance.
Reduce stress. Learning to manage stress can sometimes influence
how you feel about your body and weight. You might be surprised how
reducing stress in other parts of your life can put your whole life
Click here for more info on
Sheri Barke, MPH, RD
COC, Student Health & Wellness Center