The Glycemic Index Diet for Dummies (9 page)

The reason for the benefit of a low-glycemic diet rests on lower blood sugar levels and a decreased need for insulin. When blood sugar levels increase, the body produces more insulin to join with blood sugar and transport it into cells to provide energy. At the same time, elevated insulin levels lead to inflammation within the blood vessels, and this inflammation plays a role in the development of plaque. Plaque inside arteries narrows blood vessels and causes them to be less elastic, which can increase blood pressure levels or even lead to heart attack or stroke.

Heart disease is the culmination of a series of several events. Decreasing your risk of heart disease requires an interwoven web of strategies, including using the glycemic index within the framework of other nutrition and exercise recommendations to promote a healthy heart and cardiovascular system.

Can a low-glycemic diet also help prevent cancer? Scientists know that the traditional Mediterranean diet, which is based on vegetables, olive oil, seafood, and minimally processed grains, helps prevent several types of cancer. Turns out the Mediterranean diet is also a low-glycemic way of eating. Teasing out which specific nutrients or eating habits cause or prevent cancer is a complex endeavor, and the research often shows conflicting results. Larger long-term studies are necessary before scientists can truly understand the role the glycemic index plays in the development of cancer, but right now it's a good bet that choosing a low-glycemic diet, in conjunction with other protective eating habits, will give you added protection against developing cancer.

Increased energy

Knowing which foods to eat before, during, and after exercise based on their glycemic index level helps athletes maximize their energy and recovery time. Even if you're not a world-class athlete, or even a weekend athlete, understanding how the glycemic index of foods affects your energy levels can help you stay alert and focused throughout the day. The human body digests and metabolizes low-glycemic foods slowly, thereby providing a continued amount of energy for working muscles. High-glycemic foods, on the other hand, are quickly digested, meaning their carbohydrates are readily available to power hard-working muscles.

Start your day with a breakfast that's built on lower-glycemic foods to provide longer-lasting energy and wake up your brain. Serve a low-glycemic breakfast cereal (such as rolled oats), top it with some fruit, and pour a glass of fat-free milk for a balanced, low-glycemic breakfast that'll give you sustained energy throughout the morning. (If you ever wondered why a breakfast of sweetened cold cereal and fruit juice led to an energy crash and spike in appetite midmorning, now you know why: You chose higher-glycemfoods, which only provide energy for a short period of time.)

Instead of relying on caffeine or high-glycemic processed foods at lunch to boost your energy, build a balanced lunch around low-glycemic foods such as legume-based soups (lentil, black bean, split pea) or tossed salads that include legumes (garbanzo beans, kidney beans, or edamame are great choices). Or try spreading hummus on a slice of whole-grain bread topped with lean turkey and as many vegetables as you can pile on. You'll find that eating a low-glycemic noontime meal means you don't find yourself yawning and falling asleep midafternoon due to a drop in blood sugar levels. Plus you won't find yourself staring at the vending machine, trying to decide which candy bar will give you energy without expanding your waistline.

Improved mood

People really are what they eat in the sense that some foods can build a sunny disposition and other foods can bring you down faster than the drop of a rollercoaster. One of the most important neurotransmitters that determines mood is
serotonin.
High levels of serotonin boost one's mood, decrease food cravings, and promote restful sleep. Low serotonin levels have the opposite effect, making you feel tired, cranky, and out of sorts. The amount of serotonin in your bloodstream and brain is strongly linked to the foods you eat, especially to foods that contain carbohydrates. Once again, the type of carbohydrate-containing food you choose is crucial. Eating sugary foods when you're stressed causes a quick release, which feels great at the time but not so great when your blood sugar and serotonin levels come crashing down shortly afterward.

Does this sound familiar? You're feeling tired and cranky midmorning at work (probably because you skipped breakfast and relied on a sugary coffee to get you going) so you grab a donut, bagel, or cookie and drink a sugary beverage for energy. You love the quick mental boost, but 30 minutes later you feel shaky, tired, and out of sorts — again. You've just experienced the effects of serotonin levels rising and falling firsthand. Replace those high-glycemic foods with low-glycemic choices, however, and you get a slow, sustained release of insulin that keeps your blood sugar levels even, followed by a gradual rise in serotonin. No rapid rise and no rapid crash of serotonin levels means you have a sunny, even mood all morning.

Chapter 2
:
All Carbs Aren't Created Equal

In This Chapter

Understanding the differences between carbohydrates

Discovering how the glycemic index is measured

Making the best carbohydrate choices

Presenting the dynamic duo weight-loss weapon: low-glycemic/high-fiber foods

C
arbohydrates (which are found in foods and aren't a food group of their own) are a big topic in the world of weight loss and health thanks to the low-carb craze and today's numerous modified-carb diets. The problem is not all carbs are created equal, so you can't treat them equally. You've probably heard or read about simple versus complex carbohydrates, fiber content, white versus whole grain, and so on. Throw in the glycemic index and figuring out what you're supposed to focus on for your health gets really confusing!

But it doesn't have to be that way. Yes, when considering carbs, you need to look at many factors, including the glycemic index, nutrients, and fiber. However, simple guidelines are available that can help you make the best choices for your health — and for successful weight loss.

This chapter presents some basics on what makes carbohydrates different and how the glycemic index comes into play so you can make the best choices for a healthy low-glycemic diet.

Distinguishing Friendly Carbs from Foes

To better distinguish carbohydrates that can help your diet from those that can harm it, you should really know a little basic info about carbs in general.
Carbohydrates
are your body's major fuel source. They all break down into blood glucose, but they react differently in your body depending on their type. Carbs come in two varieties:

Simple carbohydrates,
which contain one or two sugar units

Complex carbohydrates,
which contain multiple sugar units

In the past, scientists thought that simple carbohydrates raised blood glucose levels quicker than complex carbohydrates because of the length of the sugar units. However, the latest discoveries with the glycemic index show that all carbohydrates, simple
and
complex, vary greatly in regard to their blood sugar response.

The glycemic index actually simplifies that technical mumbo jumbo a bit. Instead of focusing on complex versus simple carbs to find your best food choices for weight loss, you can focus on choosing low-glycemic foods that have a high nutrient content. Low-glycemic foods are therefore the new "friendly" carbs, and high-glycemic foods are the new "foes."

Most people think of sugar, sweets, or white flour as simple carbohydrates that make for unhealthy choices. However, the issue isn't quite that black and white. Consider the case of white flour. Often mistakenly lumped in the simple-sugars category, white flour is actually a complex carbohydrate, and complex carbs are typically labeled as "good carbs." So not all complex carbs are necessarily the healthiest choices. White flour is an example of a high-glycemic "foe," spiking the blood sugar much higher and faster than its whole-wheat counterpart (a low-glycemic "friendly" carb).

You can't tell what food is friend or foe just by looking. Instead, the food must undergo scientific testing to determine how it responds in the body. Keep reading to find out how to know which foods are friends and which foods are foes.

Measuring a Food's Glycemic Index

What makes a food low- or high-glycemic? First off, only foods that contain carbohydrates can be considered low-, medium-, or high-glycemic. Foods such as meats, poultry, fish, and fats (think oil and butter), don't contain carbohydrates, which means you have to rely on your nutrition know-how to determine what kinds and how much of them to eat.

The
glycemic level
of a food measures how fast that food is likely to raise your blood sugar. A food that raises your blood sugar quickly is considered
high-glycemic,
and a food that raises it slowly is considered
low-glycemic.
Foods that fall somewhere in the middle have (you guessed it) a medium glycemic level.

Basing food choices solely on the glycemic index can be dangerous because that means you're only looking at one aspect of food and ignoring other important ones (such as calories, amount and type of fat, and vitamin and mineral content). Many people think that whole grains, fruits, and vegetables naturally fall into the low-glycemic category. Although this is true much of the time, it isn't always the case. Some of these foods actually have a high glycemic index, and many nonnutritious foods, like certain candies and chips, have a low gcemic index. Don't simply take the road of "all low-glycemic foods are okay, so I can eat as much of them as I want." That's what happened during the lowfat craze of the '80s and '90s. People started eating fat-free everything, even if it meant higher sugar and calorie content. The same trend is emerging with low-glycemic foods; don't give in to it!

The glycemic index is a great tool, but you also need to make sure you're eating nutritious foods most of the time and not filling up on candy and chips just because they're low-glycemic. Don't toss everything you know about good nutrition out the window.