Newt Bytes April 2003
by Geof Newton
The Nutrition Pursuit - Part I [go
to Part II]
[The Evaluations] [The
Timings]
A few years ago, I put together a
running log in Microsoft Excel loosely based on the efforts of a number of other
runners from an on-line community. Over the years, the log has evolved, becoming
more complex in step with my increasing complexity as a runner. As I refine the
craft of running, so must I refine the tools that I use to measure my
performance and maximize my potential. Last year, I added a column to track the
calories expended for each exercise entry. Eventually, I wanted to add
functionality that would allow one to track calories consumed. Since losing
weight is largely a matter of expending more calories than one consumes,
comparing calories in against calories out would provide an easy way to
maintain, lose, or gain weight. Realizing that providing an entire 25,000 food
item database with full nutritional information and search capabilities within
Excel was probably a bit of a stretch, I decided to do a little shopping to see
what was going on in the world of nutritional software. As I explored and
scribbled notes, it soon became apparent that this was much more material than
would adequately fit in one column. This, then, is the start of a multi-part
column investigating nutrition resources and software currently available
on-line and as downloads. In this column, we’ll define some of our terminology,
our goals, and look at some of the on-line nutrition resources.
First, let’s define our goals. I am
looking for a program which will allow me to log my daily exercise (calories
expended) and critical measurements (resting heart rate, weight), account for my
basal metabolic rate (the amount of calories I expend just being), allow me to
enter the foods that I eat (calories input), and calculate the nutritional facts
for the day. It should be able to calculate and track calories from fat,
protein, and carbohydrate and provide some insight into key vitamins and
minerals. At the same time, my wife is looking for a program which will help her
lose some weight by tracking what she eats and whether she’s running a calorie
deficit or surplus for a given day.
Let’s start with a few quick
definitions. I’ve already mentioned basal metabolic rate or BMR. That’s the
number of calories that you burn in a normal day without any exercise. This
includes sleeping, writing, sitting, standing, and so on. BMR is typically
estimated using the Harris-Benedict equation which takes height, weight, age,
and general activity level into account (http://instruct1.cit.cornell.edu/Courses/ns421/BMR.html).
What’s a calorie? Actually, that thing that we see listed on the side of the box
of most foods that we consume is Calories with a capital “C” which is equal to
1000 calories with a small “c.” A Calorie is also known as a kilocalorie. A
calorie in chemical terms is a unit of heat equal to 4.184 joules of energy.
Before I scare you away with the chemistry and the physics, a calorie is simply
the amount of heat required to raise the temperature of 1 gram of water 1 degree
Celsius (http://whatis.techtarget.com/definition/o,,sid9_gci771826,00.html).
Analysis of the components of a
particular food entails breaking the food down into the bits that our bodies
use; fat, protein, and carbohydrate. Fats, proteins, and carbohydrates can in
turn be broken down into their various components like saturated and unsaturated
fats, animal and plant proteins, sugar and starch. Conveniently, government and
private labs have done most of the hard work of analyzing various food products
for us and have released databases of various commercial and generic food
products. The government food database is maintained by the USDA and is
identified as SR-xx. SR stands for Standard Reference and the current version is
release 15, or SR-15, with release 16 due out some time this year. The SR
database consists of over 160 vitamins, minerals, and other nutritional elements
for about 6000 food items and is available to the public free of charge in a
text file format or a Microsoft Access database (http://www.nal.usda.gov/fnic/foodcomp/Data/SR15/sr15.html).
The SR data serves as the foundation for most commercially available nutritional
logging and analysis programs on the market.
Remember that food pyramid thing from health class in Jr. High School? How does
that fit into all this? The USDA food pyramid is based on a generally accepted
ratio of the various nutrients for a “typical” individual. The nutrient ratio
based on the food pyramid usually breaks down to about 55% of calories from
carbohydrates, 30% from fats, and 15% from protein (or 55-30-15 in CFP
notation). You can learn all about the food pyramid at the USDA Center for
Nutrition Policy and Promotion (http://www.usda.gov/cnpp).
Does that mean that those ratios are right for you? If you’re a sedentary
American, you’re probably okay. If you’re a competitive athlete, you probably
need more protein and a little less fat. A number of popular diet plans have
been based on twiddling with the nutritional ratios and altering how your body
selects and burns fuel. The most well known among these of late are the Zone
diet (http://www.zonediet.com/) which is
based on a 40-30-30 ratio, and the Atkins diet (http://atkinscenter.com/)
which takes the radical approach of almost completely removing carbohydrates
from your diet for a period of several weeks. In theory, this trains your body
to get the bulk of its energy from burning fat rather than from burning
carbohydrate causing you to lose extra fat weight.
Before closing this column out for
this issue, let’s take a look at a couple of other on-line nutritional
resources. Just like the USDA, the American Dietetic Association maintains a
full library of nutritional publications on-line at
http://www.eatright.org/. They’ll also
help you find a licensed dietitian or nutritionist if you need assistance
getting on the right food program. The Nutrition Navigator site at Tufts
University (http://navigator.tufts.edu/)
is a comprehensive guide to nutrition websites rated by an advisory board of six
leading nutritional experts. They rate each site on content and usability and
then give the site an overall score on a 25 point scale. As an example, the
Atkins site scored a “12” for being “long on promises but short on science.”
Another great place to visit is the Sport Nutrition section of the Sportscience
site (http://www.sportsci.org/jour/sportnutr.html).
Sportscience presents leading edge research exploring the worlds of endurance,
strength, and speed sports. WARNING! We’re talking real SCIENCE here! For
homework, take a look at some of the foods that you’ve been eating with the
University of Illinois’ Nutrition Analysis Tool (http://www.nat.uiuc.edu/mainnat.html).
In the next column, we’ll start
taking apart some of the programs to see how they perform their various duties
and how well they meet our criteria. Until then, take a few minutes each day and
write down the things that you eat. Next, think of yourself as your favorite
fast car. Are you fueling yourself with the high-octane, expensive stuff or are
you using water? Are your calories coming from the fruits, vegetables, and meats
of the organic farms of the mid-west or are they coming from McDonald’s, Burger
King, and Ocean State Job Lot? As you eat, so shall you run, bike, swim, blade,
and lift.
Until next time, keep those fingers and mice clicking.
Cheers … webrunr@capecodathleticclub.org
[go to Part II]
Columns represent the opinions of the individuals and do
not necessarily reflect the attitudes of the club.