WHY CARBOHYDRATES MAKE YOU FAT
by Dr. Philip Maffetone
Dr. Philip Maffetone writes and lectures extensively on human performance. His patients have
included triathletes Mark Allen, Mike Pigg, Colleen Cannon, and Tim and Tony DeBoom;
marathon runner Priscilla Welch; and many others. Dr. Maffetone is the author of In Fitness and In
Health.
Whether you work out three hours per week, or 30, your diet is one of the most important factors
that determine what you use for energy. Today's school of thought on high-carbohydrate, low-fat
diets is quickly changing, as people begin to realize that even after consistently working out they are
not losing body fat.
Since most carbohydrates contain little or no fat, you may not think that carbohydrates can add to
your fat stores. Yet, at least 40% of the carbohydrates you eat are stored as fat. Consuming too
many carbohydrates -- even fat-free -- can actually make you fat. That's because of the way your
body stores and uses the end product of the carbohydrates you consume.
Carbohydrates, whether they are in the form of pastas or chocolate cake, turn into glucose once
they enter the bloodstream. Sugar is sugar -- the body doesn't discriminate. So if you consume
excess amounts of carbohydrates, your blood sugar levels increase, triggering your pancreas to
release insulin. Insulin controls where blood sugar is stored. Some is used for energy, and some is
stored in the muscles as glycogen (the stored form of sugar). Since your body can store only 2,000
calories as glycogen, the excess is stored as fat. Insulin also prevents existing fat from coming out of
storage for use as energy. If you don't access your fat stores and burn body fat, you continually
store the carbohydrates as FAT. The key is to use more stored body fat for energy; otherwise, you
will burn more sugar and just store fat.
You can control what fuel your body burns through diet, If you eat predominately carbohydrates,
your blood sugar may become unstable; and you will burn that readily available, although inefficient,
fuel first because the presence of insulin inhibits fat mobilization for energy. This is why many people
"hit the wall" at 20 miles in a marathon. They have run out of carbohydrates, not fat. If you avoid a
high-carbohydrate diet and eat the proper balance of carbohydrates, proteins, and fats, your body
will primarily burn stored body fat. All natural fats -- such as omega-6 (found in vegetables) and
omega-3 (found in fish) -- are good for you as long as you consume them in moderation.
Since efficient body chemistry is difficult to measure, you should keep tabs on how you feel.
Common symptoms of excess carbohydrates include sleepiness after eating, cravings for sweets,
hunger within two hours of a high-carbohydrate meal, and the need to snack all day. When you
don't burn enough body fat, you experience a dwindling of energy level.
A faster metabolism burns more fat, which provides you with more than twice the energy of
carbohydrates. The more fat you access for energy, the more endurance your will develop and the
leaner and faster you will become. If you cannot go for approximately four hours without eating at
work or training, chances are you are eating too many carbohydrates.