By Willow Lawson, published on March 12, 2004 - last reviewed on June 9, 2016
It happens all the time. Millions of
Americans swear to lose weight, and at first they follow through, but sooner or later, that lunchtime salad bar begins to look less and less appealing.
Drastic changes in eating and exercise habits can be difficult to
maintain for the long term, but there is one simple change in diet that
is easy to incorporate. It raises energy levels throughout the day and
can help a fledgling gym-goer make it to the treadmill after work.
The key is eating more "slow" carbohydrates, also known
as complex carbohydrates, or, for those who see life in simpler terms,
"good" carbs. A slow carbohydrate raises blood sugar levels
gradually, providing a steady stream of energy to our body's cells,
and especially our brains. Whole grain foods—such as oatmeal, whole
wheat bread, brown rice, lentil soup and beans—are great slow
Fast carbs, on the other hand, are digested quickly, causing a
spike in blood sugar followed by a steep drop as the pancreas produces
insulin to funnel extra energy into the body's cells. Processed
foods that contain refined sugar and white flour are fast carbohydrates.
As any junk-food junkie knows, they give us a roller-coaster ride of
mental energy and turn mental sharpness into mental dullness faster than
you can say "doughnut."
The body yearns for another pick me up shortly after snacking on
fast carbs. A diet high in refined carbohydrates can also lead to insulin
resistance—the beginnings of type 2 diabetes, which is sweeping the
U.S. with devastating health consequences.
An easy way of fitting slow carbohydrates into one's diet is
by eating the whole grain equivalent of whatever is on the menu: brown
rice instead of white rice, multi-grain bread instead of white, whole
wheat pasta instead of standard spaghetti.
Beyond eating more whole grain foods, a handy way of determining
whether a food is a slow or fast carb is to visit www.glycemicindex.com,
a website run by Sydney University's Glycemic Index Research
Service in Australia. The website allows the user to look up a
food's score on the glycemic index, a scale that measures how a
food's carbohydrates affect blood sugar levels.
The lower the number, the slower the carbohydrate, the steadier
your supply of energy, the more endurance you will experience, and the
longer you will feel full. Lentils, for example, score 40, a relatively
low number for a food that provides plenty of carbohydrate energy.
A baked potato, on the other hand, can score as high as 111 on the
glycemic index, a very high score. In general, potatoes and starchy
grains, especially processed cereals like cornflakes and bran flakes
score high on the GI. The index measures only foods that contain carbs,
so meat, eggs, nuts and some vegetables aren't included in the
Eating more low-GI foods will not only give you a steady source of
fuel throughout the day, it will also help you eat less—and that
can make up for a missed workout. Your body has to work harder to digest
these fiber-rich foods before the energy can reach your
The extra bulk has the added advantage of keeping the stomach
feeling full. In a study published in the journal Pediatrics,
children who started their day with high fiber breakfast foods like
All-Bran, muesli or oatmeal ate less food at lunch. Kids who ate
low-fiber (and higher GI) foods like corn flakes, puffed rice and white
bread were inclined to eat more at lunch. Both groups reported feeling
the same level of satiety after breakfast.