The glycemic index

What the glycemic index means to the dieter and common problems related to glucose.

The glycemic index was developed in the early 1980’s by David Jenkins, PhD., as a tool for diabetics for whom large rises in blood sugar are undesirable. The scientific concept of the glycemic index was proposed 25 years ago as a way to help control diabetes.  By late 1990, this research had spread to the general public as the theory of “insulin resistance.”  Insulin resistance is insulin’s inability to effectively cause an uptake of glucose for energy in the body. The hormone Insulin’s job is to regulate blood sugar levels, while delivering energy in the form of both sugar and fat to your body’s cells.  Insulin resistance can occur more easily if you are overweight or as you age.  However many individuals may have more insulin resistance simply due to genetic makeup.

Glycemic Factoid:  Insulin is a hormone secreted by the pancreas in response to a high blood glucose concentration.  It assists cells in drawing glucose from the blood.  Insulin resistance is a condition in which the body doesn’t respond to insulin properly.

What I find strange is that the glycemic index has become a mainstream concept for everyday eating, which is not easy to adhere to. We need to consume a variety of foods from all food groups to provide adequate nutrients (carbohydrates, protein, and fat), but glycemic indexing applies solely to “carbohydrate” rich foods. The nutritional benefits of consuming a variety of different foods are many.  I suggest you base your choices on the overall nutritional value of each food, particularly when considering fiber, saturated fat, sodium and salt content.

For the last several decades most of the diet books seem to focus on the glycemic index and its effect on the body’s fatness and general weight. The glycemic index ranks carbohydrate-containing foods (grains, fruits, vegetables, and dairy) by their effect on blood sugar.  The glycemic effect refers to the extent to which a food raises the blood glucose (sugar) concentration while glycemic index (GI) is a ranked measure of the glycemic effect of foods. Consider the GI screening of foods as damage control, with benefits that extend beyond the physiology of fat metabolism. And as if these concepts weren’t enough, carbohydrate rich foods are described by their glycemic load (GL).  The GL should be seen as a tool allowing you to make wise choices within the same food groups because it accurately reflects the glycemic impact of both the quality and quantity of carbohydrates present in a particular food.  Research shows that keeping blood glucose levels in check decreases cravings and appetite, while reducing the risk of diseases like diabetes, heart disease, and cancer.  Hey, science can’t do better than that.

Today’s food decisions are tough.  You have the power to choose sugar over rice, potato chips over whole-grain bread, or sweet potatoes over wheat pasta. Go to your local book store, walk into the nutrition section, and you will see a parade of diet books touting a selection of foods aiming to balance your blood sugar level.  Diet book after diet book claims that these foods can help you lose more weight “easily” and help prevent diabetes and heart disease. If you actually commit to following this diet plan, there is the promise you will diminish the impact that any food has on your glucose level and on your body’s ability to burn fat, especially that unwanted “belly fat.” To be honest, I have read more than my share of the low-carb, low-fat, or high-protein diets books like Sugar Buster; The Perricone Promise; The South Beach Diet; The Thyroid Diet; The Zone; Glucose Revolution; Eat More, Weigh Less; The Fat Resistance Diet; Glycemic Index Weight Loss; Atkins for Life; The Volumetrics Eating Plan; The Ultimate New York Body Plan; Eating by Blood Type; Healthy for Life; and everything in between. The food selections and diet decisions tend to be based on the glycemic index (GI).  Some researchers, scientists, registered dietitians, nutritionists, doctors, and other medical and health care professionals hold to the premise that a carb is a carb and overall daily calories matter.  They try to make it easy by stating you should stay away from “simple or refined” carbohydrates and focus your diet on “complex” carbohydrates.  What the average American hasn’t grasped is that these recommendations have played center stage to our nation’s obesity epidemic, the increase in type 2 diabetes, cardiovascular disease and other health related issues.

The index for carbohydrates does provide an essential piece to a nutrition strategy but it has its limitations.  What the general population doesn’t understand is that the glycemic index is not necessarily a measurement that reflects total nutritional values, but it can help you choose foods that will keep your cravings, hunger, blood sugar, and serving size in check.  The downside to the glycemic index rests with the testing centers which rate these carbohydrate foods in isolation, which doesn’t accurately represent how we eat.  Meals typically contain a mixture of foods, which can easily make the glycemic response to a particular food unpredictable and varied in levels of absorption.  A factor such as food acidity, fat, protein, or fiber content automatically lowers the glycemic index.  Other variables, such as how a food is processed and prepared, also affect its glycemic rating.  For instance, if you eat a baked potato with butter, it is digested more slowly due to the saturated fat in butter.  Another example of glycemic variations is a simple piece of fruit which varies in sugar content based on its ripeness, versus the uptake of juice which is like drinking sugar.

Simply stated, carbohydrates that measure low on the Glycemic Index (typically referred to as complex carbohydrates) are broken down more slowly by your body and promote stable blood sugar.  Those carbohydrates ranking high on the GI scale (typically referred to as simple sugar and starches) enter the blood stream much quicker, promoting spikes in sugar level, which in turn triggers extra insulin to be released.

Whether a food gets labeled as simple or complex, carbohydrates cause an elevation in blood sugar; followed by a subsequent release of insulin from the pancreas to swipe the sugar from the blood stream and then into the tissue for future use as energy. Unfortunately, everyone is engineered differently so it stands to reason that different individuals have various reactions to sugar. Numerous studies have revealed chronic overeating of high GI ranked foods may increase an individual’s resistance to insulin’s effect, which promotes a condition called metabolic syndrome.  Metabolic syndrome is also referred to as insulin resistance syndrome or syndrome X.  It is a disease surrounded by various risk factors: diabetes, obesity around the mid-section, hypertension, and high blood cholesterol, which over time greatly increases a person’s risk of developing cardiovascular disease.  As resistance syndrome worsens more insulin is required from the overactive and highly sensitive pancreas, which translates into high insulin levels in the blood, which in turn tells the body to store fat.  All of this explanation is to say that this is why the glycemic index has become the cornerstone for many diets. The GI of a food has become a popular way to market and sell the regulation of blood sugar, which has turned into a multi-billion dollar industry.

The low glycemic approach, simply stated, is that carbohydrates that measure low on the glycemic index (typically referred to as complex carbohydrates) are broken down more slowly and promote stable blood sugar.  Those carbohydrates ranking high on the GI scale (typically referred to as simple carbohydrates) enter the blood stream much quicker, producing spikes in blood sugar levels which trigger extra insulin to be released. (For more information read RESISTANT STARCH, referred to as the third type of fiber and its effect on blood sugar response.)

Generally speaking, foods ranking high on the GI scale are made from refined grains, such aswhite bread, crackers, baked potatoes, and white rice.  Foods such as beans, fruits, and vegetables rank low on the GI scale.  My advice to clients is to consume foods that generate a minimal yet steady increase in blood sugar levels, which will delay the hunger response. I believe Atkins was on to something, but most people can better control their weight by reducing the glycemic load of the diet then by any other strategy.

A healthy diet should focus on whole grains, vegetables, legumes, fruits, lean protein, and moderate fat intake. These types of food choices will provide your body with significant benefits – promoting more energy and reducing blood glucose (sugar) and insulin levels throughout the day, while increasing your sense of control over your cravings and consumption. (For more information on high protein consumption read “Protein 101”.)

Take a moment to visualize a 10-inch dinner plate. The portions should reflect 50% fruit and vegetables (with a ratio of 1fruit : 3 vegetables), 25 % protein, and 25 % whole grains such as barley, quinoa, basmati or converted long-grain rice, couscous, cracked wheat, and whole-grain pasta, with no more than 25% to 35% of your overall caloric intake coming from fat.

The Glycemic-Index Rating Process and Procedure

The glycemic-index is a 0-100 scale measuring how a carbohydrate in a particular food affects blood sugar levels.  All carb foods are tested in isolation (a non-meal situation) following an internationally standardized protocol.  In order to test the glycemic-index of a food, the testing centers require a group of ten subjects.  All candidates are subjected to an overnight fast, then each subject consumes a measured portion of the test food (typically based on 50 grams = 200 calorie serving of carbohydrates yet it can vary).  Blood samples are taken at specific intervals (15 to 30 minutes) over a two hour period.  The test centers are watching the subject’s blood glucose levels rise than fall using an algorithm.  The researchers then take the average of the whole group.  By ranking foods according to their ability to elevate blood sugar, nutrition professionals can help people make responsible food choices.

If you have any questions, access the online GI database at www.glycemicindex.com.  For more information about the Glycemic Index Tested program and the most current information on food products approved, go to www.gisymbol.com.au.

The GLYCEMIC INDEX of Some Ordinary Foods:

High* (70-100):  Rice cakes, cornflakes, white bread, whole-wheat bread, Cream of Wheat, Cheerios, baked potatoes, white rice, new potatoes, bagels, jelly beans.

Glycemic Factoid: When high glycemic foods are consumed with protein, fat, fiber, or low GI foods, the overall GI value of the meal will typically be medium.

Other foods identified as High GI (higher than 70):

Bread, French baguette/1 ounce/95

Potato, baked/1medium/85

Cereal, Bran Flakes/1/2cup/74

Potatoes, mashed/1cup/73

Cereal, Corn Flakes/1cup/92

Pretzels/1ounce/83

Cereal, Grape-Nuts/1/4cup/75

Puffed rice cake, white/3 cakes/82

Cereal, Total/3/4cup/76

Rice, instant, white/3/4cup, cooked 87

Doughnut, cake-type/1.75ounces/76

Scone, plain/1ounce/92

English muffin/1ounce/77

Stuffing, bread/1ounce/74

French fries, frozen, heated/30fries/75

Waffles, Aunt Jemima/one-4-inch/76

Gatorade, orange-flavored/1cup/89

Watermelon, fresh/4ounces/72

Popcorn, plain, cooked in microwave/ 1½ cup/72

*Source: The New Glucose Revolution: Complete Guide to Glycemic Index Values, Marlowe & Company, 2003

Glycemic Factoid:  4 teaspoons of vinegar on your salad can reduce the glycemic value of your meal by about 30%. Use lemon in your tea and/or water. Make guacamole with fresh lime, and consume acidic foods such as pickled beets and okra or chutney.

When referring to high glycemic indexed foods, think “highly processed.”  Take a plain old potato for instance: how you prepare a potato will alter its GI score considerably.  Potatoes are natural food products (carbohydrate), which in their natural state automatically score very high on the glycemic index and glycemic load.  To make matters worse, potatoes are a very popular food in the United States and can be gotten baked, boiled, fried, au gratin, mashed, and instant (flakes).  Of course potatoes are also added to soups, sauces, fillings, and all kinds of ordinary and gourmet dishes.  I bet other than eliminating bread, eliminating potatoes would be one of the biggest changes to the American diet.  Let’s look at the numbers:

White Potatoes                                    85(GI)             26(GL)

Baby Red New Potatoes                     57(GI)             12(GL)

Sweet Potatoes                                    61(GI)             17(GL)

Instant, mashed                                   85(GI)              17(GL)

Mashed                                                92(GI)              18(GL)

Q: What factors of food determine whether a food is high or low on the glycemic index?

A: The only factors to consider are how the food was processed and prepared for consumption. How food is prepared has a significant influence on its glycemic index and load. Eat foods as close to their original state as possible.

Various factors affect the GI index and load of a food:

  • Degree of processing
  • How gelatinized the starches are
  • Level of fiber
  • Amount of fat

Bottom line, raw food has a lower glycemic index than its cooked counterpart.

When you get into the preparation of a food, hard compact starches found in potatoes and other carbohydrates expand when they are heated. At this point, starches are easy to digest and can be absorbed by the starch-digesting enzymes of your small intestines as easily as your favorite dessert.

Glycemic Factoid: Too many additives, high temperatures, and over-cooking can transform a low-glycemic carbohydrate into a high-glycemic carbohydrate.

The concept of glycemic load can give you a much better snapshot of one’s response to a particular food.

Glycemic load is the weighted average glycemic index of a particular food X and the % of dietary energy or grams of carbohydrates (4kcal per gram = calories) that food contains.  It becomes easy when you have The NutriBase Complete Book of Food Counts, which provides access to a food composition tables.  But if you’re the type who wants to calculate the glycemic load of a quantity of carbohydrates, multiply the glycemic index value times (X) the quantity of carbohydrate serving in grams (1 g = 4 calories), then divide by 100.

GI value X grams per serving / 100 = GL

For instance, a 5-ounce russet potato has both a high glycemic index and a high glycemic load, which will increase your blood sugar level and stimulate an increase in your insulin level — just from eating an innocent baked potato with your meal. Let’s calculate a 5-ounce baked russet potato without fat:

1medium/5 oz. russet potato with a GI value 77 and available carbs 30g divided by 100 equals a GL value 23

30 grams of carbohydrates X 77 glycemic index value = 2,310 / 100 = 23 glycemic load

I told you this little story simply to emphasize  that all carbohydrates are not created equal, a calorie is not a calorie, is not a calorie, and the glycemic index is only one of many considerations to take into account when choosing your foods.  This little piece of advice is especially important if you suffer from insulin resistance syndrome or tend to be overweight.

Moderate* (55-70):  Pita bread, bananas, sucrose (table sugar), corn, raisins, brown rice, Shredded Wheat. Other foods identified as Medium GI 55-70:

Basmati rice/1cup, cooked 58

Muffin, blueberry/1small/59

Beets, canned/1/2cup/64

Muffin, bran/1small/60

Bread, light rye/1ounce slice/68

Oatmeal cookies/4small/55

Bread, pita, white/1ounce/57

Oatmeal, instant/1cup/66

Bread, rye/1ounce slice/58

Pancakes mix/2 – 4inch pieces/67

Bread, white/1ounce slice/70

Pizza, cheese/1slice/60

Cereal, muesli, Swiss formula/1ounce/56

Potatoes, new/1cup/62

Cereal, Raisin Bran/1/2cup/61

Raisins/1/2cup/64

Corn/1/2cup, cooked/60

Rice, white, long-grain/1cup, cooked/61

Couscous/3/4cup, cooked/65

Soup, black bean/1cup/64

Hamburger bun/1.5ounces/61

Soup, pea, canned/1cup/66

Honey/1tablespoon/55

Taco shells, 2 – baked/68

Tortilla chips, plain, salted/1.75 ounces/63

* Source: The New Glucose Revolution: Complete Guide to Glycemic Index Values, Marlowe & Company, 2003

Low (below 55):  Most white or wheat pastas, fructose, apples, beans, lentils, oranges, sweet potatoes, oatmeal (slow cooking variety), pears, pumpernickel bread, milk, and almost all whole vegetables are classified as desirable carbohydrates.  Let’s talk about vegetables for a second.  Vegetables contain vital nutrients, tend to be low-glycemic, and have low-glycemic load.  You should be planning all your meals around vegetables, giving veggies 50% of a ten-inch plate or if you want a serving break down:

  • Non-starchy vegetables 3-5 servings (1 serving = 1c raw or 1/2c cooked)
  • Fruit 2 to 4 servings daily (1 serving = 1c )

You should be concerned about any product which has high fructose corn syrup as an additive, which is no different than sugar. Limit your intake of fruit juice, dried fruit, tropical fruit, and canned fruit in any kind of syrup.

  • Grains and starchy vegetables 4-8 servings daily (varies a lot depending on the food.  1 serving = to anything from a 1/2c to the size of a CD case).  Potatoes, parsnips, beets, rutabaga, corn, peas, winter squash, and beans, aren’t in the vegetable group.  These foods act more like grains, and you just can’t eat unlimited amounts.  And potatoes are classified as a vegetable, since they come from the ground, but unfortunately you must limit your intake to about half a baked potato. Even the government classifies French Fries as a vegetable, but due to the preparation, I treat them more like fat or a treat (0-2 servings = one handful in the palm of your hand)
  • Beans and legumes are in this category and represent terrific foods, full of vitamins, minerals, and tons of fiber.  They are also considered a good meat alternative because of their protein value. So beans should be actually viewed as a source of protein and complex carbohydrate. You can see that it is not so easy to put a label on all specific foods.

Glycemic Factoid:  These ranges are according to The Glucose Revolution, Marlowe & Company, New York, 1999.

Other foods identified as Low GI (lower than 550):

Apple/1 medium/38

Lentils, green/3/4 cup, cooked/30

Artichokes, Jerusalem/1/2 cup/0

Lettuce/4 leaves/0

Avocado/1/4 cup/0

Lima beans, baby frozen/3/4 cup/32

Baked beans/2/3 cup/28

M&M’s peanuts/15 pieces/33

Banana/1 medium/52

Mango/4 ounces/51

Barley, pearled/1 cup, cooked/25

Maple syrup/1 tablespoon/54

Beans, kidney/2/3 cup, cooked/23

Oatmeal slow cooking/1 cup/49

Black-eyed peas, canned/2/3 cup, cooked/42

Orange/1 medium/42

Bread, 100% whole grain/1 ounce slice/51

Pasta, capellini 6 ounces, cooked/45

Broccoli, raw/ 1 cup/0

Pasta, fettuccine/1 1/2 cups, cooked/45

Bulgur/3/4cup, cooked/48

Pasta, linguine/1 1/2 cups, cooked/52

Carrots/1 medium, raw/47

Pasta, ravioli, meat-filled/6.5 ounces

Cashews, salted/1.75 ounces/22 cooked/39

Cauliflower, raw/3/4 cup/0

Pasta, spaghetti/ 1 1/2 cups, cooked/38

Celery/2 stalks/0

Pasta, tortellini, cheese-filled/6.5 ounces,

Cereal, All-Bran/1/2 cup/30 cooked/50

Cherries, fresh – 18  pieces/22

Pasta, whole-wheat spaghetti/1 1/2 cups

Chickpeas, canned 2/3 cup/ 42 cooked/32

Chocolate cake, with frosting

Peach, fresh/1 large/42

from a mix/ one 4 ounce slice/38

Peas, green, frozen/1/2 cup, cooked/48

Chocolate pudding, instant, made with

Potato chips, plain, salted/2 ounces/54

whole milk/1/2 cup/47

Rice, brown/1 cup, cooked/50

Cucumber, raw/3/4 cup/0

Rice, converted, white/1 cup, cooked/38

Grapes, green, fresh/3/4 cup/46

Soup, canned, lentil/9 ounces/44

Grapefruit/1/2 medium/25

Strawberry jam/1 1/2 tablespoons/51

Grapefruit juice, unsweetened/1 cup/48

Sweet potato/5 ounces, cooked/44

Ice cream, light, vanilla/1/2 cup/50

Tomato juice, canned, no sugar/1 cup/38

Lentils, brown/3/4 cup, cooked/29

Tomato soup/1 cup/38

Yam/1 medium, cooked/37

Yogurt, low-fat, with fruit and sugar/1 cup/33

The difference between Low Carbohydrate Diet and Low Glycemic Index

Simply eating a low carb diet doesn’t mean automatically low glycemic index.  When someone says “I am on a low carb diet,” they are referring to the percentage of carbs (the overall daily consumption) consumed versus protein and fat. This signals to the consumer that the food or meal doesn’t contain much carbohydrate, while saying nothing about the “quality” of the carbohydrates actually being consumed. Ninety (90) percent of our carbohydrate intake in the US revolves around highly processed foods, made with refined flour, sugar, fat, and salt (i.e. bagels, pretzels, pancakes, waffles, pizza, many cereals, crackers, and snack foods).

According to Nancy Clark, MS, RD, author of Sports Nutrition Guidebook, “We know that a carbohydrate’s effect on blood sugar cannot be determined by whether it is simple or complex.” Clark believes today’s consumers should be more focused on the glycemic response, or a food’s ability to contribute glucose (sugar) to the bloodstream.  It seems that a food’s glycemic response is influenced by other factors, such as the amount  of food eaten, the fiber content,  amount of fat (good or bad), and the way the food was prepared.

Avoid or minimize anything using white flour, white potatoes (regardless of preparation), white rice, puffed rice, or rice cakes.  Minimize sugar, sweets, candies, and sodas. These simple carbohydrates can be found at fast food restaurants, your favorite grocery store,  and in canned, frozen, dehydrated, or freeze-dried foods, which can be highly processed with other ingredients like sugar, highly saturated or trans fats, sodium, and salt.

Glycemic Factoid: The kinds of carbohydrates you want to eat come primarily from the ground. Nature has provided humans with fruits, vegetables, nuts, legumes and grains. Complex carbohydrates are not a component of animal products, with the exception of milk products.

Carbohydrates deliver much more value than glucose (sugar). Carbohydrates such as fruits and vegetables provide fiber, vitamins, minerals, active phytochemicals, and antioxidants. The best way to utilize the concept of glycemic-index and its load may be as a decision making tool when planning a meal that will consist of carbohydrates alone. For instance, when planning a snack or meal, try consciously choosing a food with a low glycemic load, which provides a more stabilizing effect on the body and its production of insulin.

Glycemic Factoid: There are numerous studies that conclude that individuals eating a diet composed primarily of high-glycemic foods gain more weight with identical amounts of calories then those eating a low-glycemic diet.

Because everyone is uniquely engineered, each individual reacts to sugar (glucose) differently, so observe what happens after eating refined or complex carbohydrates.  How do you feel?  Does it tinker with your moods? What happens to your bodyweight, sleep, and overall health?

Think “good carb and good fat,” which means reducing the consumption of refined carbohydrates and switching to the complex variety of carbs.  A key axiom:  metabolism is far too complicated to be ruled by one theory alone.  Just focus on selecting nutrient-dense, well-balanced meals.

The GI rating is an important and valuable way of thinking about the foods we consume.  But from an every day standpoint, it makes eating unnecessarily complicated.  If you simply follow the guidelines of a healthful diet, which is comprised of more whole grains, beans, fruits, and vegetables with fiber, and cut back on simple, sugary carbohydrates and highly processed foods, saturated fats, salts and sodium, you’ll do just fine.  If your goal is weight loss, the bottom line is calories consumed combined with low glycemic food choices and exercise.  Diets that incorporate elements of the GI scale, such as the popular South Beach Diet, Atkins for Life, and other programs that publicize the GI index have one thing in common: they get you to restrict your calories. Everyone in the business of weight management knows it comes down to number of calories consumed versus activity level.  You can’t make any money selling this simple story.

Because insulin resistance syndrome can severely compromise your ability to lose weight and your overall health and wellness, start by making changes in your diet and lifestyle.  All of the following lifestyle tips could help minimize or alleviate insulin resistance syndrome.

  • Maintain a normal body weight and BMI of 24 inches or less
  • Reduce your caloric consumption
  • Lower your fat intake to 20-25% of your caloric intake and strictly avoid any product that has traces of trans fat, hydrogenated or partially hydrogenated fat.
  • Minimize your intake of saturated fat to no more than 10% of your total fat calorie consumption.
  • Increase your fiber intake from whole grains, beans, fruit and vegetables.
  • Minimize highly refined, high GI carbohydrates like white potatoes, white rice, white flour, white flour products, pasta, crackers, all snack foods, cereals, sugary candies and sweets, and sodas.
  •  When eating carbohydrates add a little lean protein with good fat to slow down the absorption into the blood stream.
  •  Engage in regular physical activity a minimum of 30 minutes per day.

Glycemic Index and Alcohol Consumption

In the case of glycemic index weight-loss program, treat alcohol as a food, containing calories (7 calories per 1 gram) and needing to be budgeted and treated as a snack or treat.  A 3.5-ounce glass of wine has approximately 70 calories and one gram of carbohydrates.  Just one ounce of 90-proof liquor has 73 calories and no carbohydrates. And 12 ounces of beer has 146 calories and 13 grams of carbohydrates.

Alcohol can increase and then lower blood sugar levels, and tends to be unpredictable.  The body uses alcohol (ethanol) as a fuel first when breaking down food, and only after the alcohol has been used up does your body start to tap into your other energy sources, such as carbohydrates and fat stores.  What that means to you is enjoying one or two glasses of your favorite wine during dinner will put a hold on any fat-burning and digestion.

Bloating

One of the most common reasons women bloat is from overeating artificial sweeteners like xylitol and sorbitol, and fatty foods, which signal your digestion to slow down. In addition, diet soda pushes air into your digestive tract.  Another reason for bloating is too much fiber added to the diet when trying to lose weight.  Add fiber gradually allowing your digestive system to adjust.  Some types of fiber, including psyllium and inulin, can worsen bloating, gas, and abdominal discomfort in individuals with irritable bowel syndrome.

Boost Your Metabolism

Many individuals on a weight loss diet suggest that a slow metabolism keeps them from losing weight.  The weight loss industry capitalizes on this belief by developing and promoting products to boost metabolism and melt away unwanted pounds.  “Metabolism” refers to the way the body uses energy (represented by calories).  The body uses energy in the following ways:

To sustain vital body functions like breathing, heart rate, waste removal, cell growth and repair when at rest, which accounts for up to 75% of the calories you burn daily.

For movement or physical activities.

As a response to the process of digestion and absorption of food, which uses about 10% of a day’s activity.

 For operating the brain, which accounts for approximately 400 calories.

The speed at which the body burns calories at rest is called your resting metabolism rate (RMR).  The only way to actually know your RMR is have a health or fitness professional calculate your RMR or measure it professionally (one such device called BodyGem, measures oxygen consumption. This reflects the rate at which your body burns calories).

Few individuals can eat anything they want and maintain a healthy weight, me included.  You can help by boosting your basal metabolic rate (BMR) which is the rate at which the body uses energy to support its resting metabolism.  Basal Metabolism is the sum total of all the involuntary activities that are necessary to sustain life, including circulation, respiration, temperature maintenance, hormone secretion, nerve activity, and new tissue synthesis, but excluding digestion and voluntary activities. Basal metabolism is the largest component of the average person’s daily energy expenditure and plays an important role in managing your glycemic index and weight shifts through increased physical activity. Yet there are many other factors that influence weight shifts.

Factors That Influence Metabolism and Body Weight

Your metabolism changes throughout your life:

Age:  After you hit your prime (30 – 35), hormones tend to fluctuate, decreasing every decade.  This is brought about by the slowing of hormone production. As the hormones decrease so does the basal metabolism rate.

Activity:  Sedentary lifestyles help to slow the metabolism.  The more you move the more calories you consume and the easier it is to manage your weight.  Do 30 minutes or more of aerobic activity at least four to five times a week.  Try power walking, cycling, or dance, and incorporate muscular strength or endurance training three times a week to increase lean muscle.

Consumption:  Avoid overeating.  Your stomach is the size of your fist.  Your body needs about that much food 3 to 4 times a day.  And if you deprive yourself of proper nutrition, your body starts thinking “famine,” which temporarily causes a slowing in metabolism as well as readjusting your set point.

Sleep:  For your metabolism to operate at its optimal level, you need adequate sleep, which means recovery.  When you burn the candle at both ends on a regular basis, your body’s stress hormones adrenaline and cortisol kick in.  This increases your body’s stress level and elevates your insulin levels, which means your body starts to store fat, which in turn causes your metabolism to slow.

Eat a Low-Glycemic Diet:  When you eat a diet high in simple sugars and starches you increase insulin levels, which encourages your body to store fat.

Eat every 3 to 4 hours: Skipping a meal can increase your hunger and cravings.

Eat Breakfast: Breakfast wakes up your metabolism after a good night’s sleep. Having breakfast replaces all the energy you used to repair and maintenance your body while in recovery and helps prevent overeating at your next meal.

Monitor your Caffeine: Caffeine, even without milk and sugar, stimulates the production of insulin because it indirectly raises your blood glucose levels by stimulating the release of glycogen stores in the body.

Limit Sweet Splurges:  Sugary foods trigger an insulin response, signaling there will be more food on the way and increasing hunger.

Supplements:  Many weight-loss supplements marketed to increase metabolism contain stimulants which speed up metabolism by increasing the heart rate. This can produce side effects like insomnia, anxiety, heart palpitations, and elevated blood pressure. Any product alluding to “enhanced metabolism” will have scarce research and a peppering of small studies with small effects. Weight-loss supplements tend to boost metabolism only slightly and can be risky.

Metabolism Enhancing Ingredients in popular supplements: bitter orange/synephrine (citrus aurantium), caffeine, cayenne/capsaicin (capsicum frutescens), EGCG/green tea (camellia sinensis), ephedrine/ma huang (ephedra sinica), forskolin (coleus forkohlii), guarana, white willow extract/salicin (salix alba), yerba mate (llex paraguariensis), yohimbine (pausinystalia yohimbe)

Exercise and the Glycemic Index of a Food

I have seen first-hand what happens when my clients consume a low glycemic diet along with moderate daily exercise.  The new behavior isn’t restricting calories but rather changing the type of calories. The exercise part of the equation simply heightens tissue sensitivity to insulin, and an active individual is less likely to suffer from insulin-related problems. The ingestion of low to moderate-GI foods pre-exercise seems to help individuals perform exercises longer by increasing the time it takes to achieve exercise exhaustion.  For glycogen replacement after intense exercise, the consensus in the nutritional community is to consume a high-GI food within 30 minutes to hours of the workout. On a cellular level, your body replaces glycogen, at the rate of 5% per hour, so consume a moderate to low-GI meal that provides a slow sustained release of blood sugar to get you through your workout, rather than a high-GI food that could possibly cause you to experience a “low” midway through your training. Then have a high-GI snack after the workout to replenish glycogen.

The Exercise Plan

  • Modest exercise 30-45minutes 5 X a week
  • Load up on vegetables (5-8 servings daily) and fruits (4-6 servings daily)
  • Add nuts, eggs, legumes, olive oil, canola oil, fish, beans (3-5 servings daily)
  • Skinless poultry (1-2 servings daily)
  • Lean red meat, pork, or wild game (occasionally)
  • Whole grains, cereals, pasta or rice (occasionally)

The Formula

  • Carbohydrates                  40 to 50 percent daily
  • Protein                           25 to 30 percent daily
  • Fat                                  20 to 30 percent daily

Weight Loss Factoid: Researchers have found if you maintain the same caloric intake yet reduce the fat calories to 20% of your overall intake daily, you will tend to lose up to 10% more weight than a traditional diet. I tried it, and guess what — it worked.

References:

> The New Glucose Revolution Shopper’s Guide to GI Values 2010: The Authoritative Source of Glycemic Index Values for More Than 1,300 Foods. Dr. Dr. Jennie Brand-Miller References: M.D. M.D., Kaye Foster-Powell M. Nutrition & Diet.

>Nancy Clark, MS, MD, Nancy Clark’s Sports Nutrition Guidebook.

>J. Brand-Miller and K. Foster  Powell, Diets with a low glycemic index: From theory to practice, Nutrition Today 34 (1999): 64-72.

>Chris Carmichael’s, Food and Fitness, Eat Right to Train Right.

>L. Kathleen Mahan and Sylvia Escott-Stump, Krause’s Food, Nutrition, & Diet Therapy 9TH edition.

>H. Katanas, , Diets with a low glycemic index are ready for practice, Nutrition Today 34 (1999): 87-88.

>Frances Sizer and Eleanor Whitney, Nutrition Concepts and Controversies, Ninth Edition.

>J. H. Cummings and coauthors, A new look at dietary carbohydrate: Chemistry, physiology and health (Paris Carbohydrate Group), European Journal of Clinical Nutrition 51 (1997): 417-423.

>C. Beebe Diets with a low glycemic index: Not ready for practice yet! Nutrition Today 34 (1999): 82-86.

>J. Salmeron, Dietary fiber, glycemic load, and risk of non-insulin-dependent diabetes mellitus in women, Journal of the American Medical Association 277 (1997): 472-477.

>Position of the American Dietetic Association: Total diet approach communicating food and nutrition information, Journal of the American Dietetic Association 102 (2002): 100-108.

>M. Wei and coauthors, The association between cardiorespiratory fitness and impaired fasting glucose and type 2 diabetes mellitus in men.  Annals of Internal Medicine 130 (1999): 89-96.

>Joint position statement of the American College of Sports Medicine and the American Diabetes Association, Diabetes and exercise, Medicine and Science in Sports and Exercise.

>U. S. Department of Agriculture, Sugar and Sweetener Situation and Outlook Report, March 1996, pp. 3-4.

>J. W. White and M. Wolraich, Effect of sugar on behavior and mental performance, The American Journal of Clinical Nutrition 62 (1995): S242—S249.

>K. McNutt, What clients need to know about sugar replacers, Journal of the American of the American Dietetic Association 100 (2000): 466-469.

>Position of The American Dietetic Association: Use of nutritive and nonnutritive sweeteners, Journal of the American Dietetic Association (1998): 581-587.

>David A. Kessler, MD, The end of overeating. Published by Rodale Books.

>Leo Galland, MD, The Fat Resistance Diet.

>The NutriBase Complete Book of Food Counts.

Internet Sites to visit:

>American Diabetes Association

>U.S. Government health information

>American Dental Association and the National Institute of Dental Research

>National Institute of Diabetes & Digestive & Kidney Diseases


>Mayo Clinic Health Letter, Glycemic Index.

>Harvard Medical School, Glycemic Index.

>Glycemic Index Laboratories.