Diabetes Diet

December 2001

WHAT IS DIABETES?

The two major forms of diabetes are type 1 (previously called insulin-dependent diabetes mellitus (IDDM) or juvenile-onset diabetes) and type 2 (previously called noninsulin-dependent diabetes mellitus (NIDDM) or maturity-onset diabetes). [For more details, see the Well Connected Report #9, Diabetes Type 1 and Report #60, Diabetes Type 2 .]

Insulin

Both diabetes type 1 and type 2 share one central feature: elevated blood sugar ( glucose) levels due to absolute or relative insufficiencies of insulin, a hormone produced by the pancreas. Insulin is a key regulator of the body's metabolism. It normally works in the following way:

Type 1 Diabetes

In type 1 diabetes, the disease process is more severe that type 2 diabetes and onset is usually in childhood:

Dietary control in type 1 diabetes is very important and must focus on balancing food intake with insulin intake and energy expenditure from physical exertion. [ See Well-Connected Report #9 , Diabetes: Type 1. ]

Type 2 Diabetes

Obesity is common in type 2 diabetics and this condition appears to be related to insulin resistance. The primary dietary goal for overweight type 2 patients is weight loss and maintenance. Studies indicate that when people with type 2 diabetes can maintain intensive exercise and diet modification programs, many can minimize or even avoid medications. [ See Well-Connected Report # 60 , Diabetes: Type 2. ]

WHAT ARE THE GENERAL GUIDELINES FOR A DIABETES DIET?

General Dietary Goals for People with Diabetes

The treatment goals for a diabetes diet are the following:

Overall Guidelines. There is no longer a single diabetes diet that will suit everyone. The overall approach is based on the US Dietary Guidelines for healthy eating for all Americans, and includes the following:

Furthermore the American Diabetes and Dietetic Association recommend a balanced meal plan for diabetes the uses the following ratios:

In general, everyone should aim for five servings of fruits and vegetables and six servings of whole grains each day and two weekly servings of fatty fish.

Some Specific Diets for People with Diabetes

Patients ideally should meet with a professional dietitian to plan an individualized diet within the general guidelines that takes into consideration their own health needs. There is no single diet that meets all the needs of everyone with diabetes. For instance, a type 2 diabetic who is overweight and insulin-resistant may need to have a different carbohydrate-protein balance than a thin type 1 diabetic in danger of kidney disease.

Healthy eating habits along with good control of blood glucose are the basic goals in managing this complex disease, and several good dietary methods are available to meet them:

If one of these approaches works in controlling glucose levels, there is no reason to choose another. Each of them can be effective, but because regulating diabetes is an individual situation, everyone with this condition should get help from a dietary professional in selecting the best method.

Monitoring

Tests for Glucose Levels. Both hypoglycemia and hyperglycemia are of concern for patients who are receiving insulin. It is important, therefore, to monitor blood glucose levels carefully. Patients should aim for the following measurements:

In general, patients who are tightly controlling glucose levels need to take readings four or more times a day. Blood glucose levels are generally more stable in type 2 diabetes than in type 1, so experts usually recommend measuring blood levels only once or twice a day. Different goals may be required for specific individuals, including pregnant women, very old and very young people, and those with accompanying serious medical conditions.

Tests for Glycosylated Hemoglobin. Another test examines blood levels glycosylated hemoglobin , also known as hemoglobin A1c (HbA1c). Measuring glycosylated hemoglobin is not currently used for an initial diagnosis, but it may be useful for determining the severity of diabetes. The test is not affected by food intake so it can be taken at any time. A home test has been developed that might make it easier to measure HbA1c. In general, measurements suggest the following:

Other Tests. Other tests are needed periodically to determine potential complications of diabetes, such as high blood pressure, unhealthy cholesterol levels, and kidney problems. Such tests may also indicate whether current diet plans are helping the patient and whether changes should be made. Annual urine tests showing even microscopic traces of a protein known as albumin can also indicate a future risk for serious kidney disease.

Preventing Hypoglycemia (Insulin Shock)

For prevention of long-term complications of diabetes, experts are now recommending that both type 1 and type 2 patients should aim at keeping blood levels as close to normal as possible. Such intensive insulin treatment increases the risk of hypoglycemia, which occurs when blood sugar is extremely low (below 60 mg/dl). The following tips may help avoid hypoglycemia or prepare for attacks.

Other Factors Influencing Diet Maintenance

Food Labels. Every year thousands of new foods are introduced, many of them advertised as nutritionally beneficial. It is important for everyone, most especially people with diabetes, to be able to differentiate advertised claims from truth. The current food labels show the number of calories from fat, the amount of nutrients that are potentially dangerous (fat, cholesterol, sodium, sugars) as well as useful nutrients (fiber, carbohydrates, protein, vitamins).

Labels also show "daily values," the percentage of a daily diet that each of the important nutrients offers in a single serving. Unfortunately, the daily value is based on 2,000 calories, generally much higher than most diabetics should have, and the serving sizes may not be equivalent to those on the Exchange Lists. Most people will need to recalculate the grams and calories listed on food labels to fit their own serving sizes and calorie needs.

Weighing and Measuring. Weighing and measuring food is extremely important in order to get the correct number of daily calories.

Timing. Meals should not be skipped, particularly for those who are on insulin. Skipping meals can upset the balance between food intake and insulin and also can lead to weight gain if the patient eats extra food too often to offset low blood sugar levels.

The timing of meals is particularly important for people taking insulin:

WHAT ARE THE MAJOR FOOD COMPONENTS IN A DIABETES DIET?

Carbohydrates

Compared to fats and protein, carbohydrates have the greatest impact on blood sugar. Evidence now suggests that it is the total amount of carbohydrates rather than the specific type that most directly affects blood glucose. Carbohydrate types are either complex (as in starches) or simple (as in fruits and sugars). One gram of carbohydrates equals four calories. The current general recommendation is that carbohydrates should provide between 50% and 60% of the daily caloric intake.

Complex Carbohydrates. In all cases, complex carbohydrates found in whole grains and vegetables are preferred over those found in starch-heavy foods, such as pastas, white-flour products, and potatoes. In one study, substituting special starch-free bread for normal bread resulted in a significant decline in blood glucose and hemoglobin A1c in type 2 diabetes. Complex carbohydrates are also the main source of fiber, which is extremely important in any health diet. [ See Box Fiber.] People with diabetes should also prefer complex carbohydrates that have a low glycemic index and are high in fiber. Generally, this means whole grains. [ See Table The Glycemic Index of Some Foods.]



Fiber

Fiber is an important component of many complex carbohydrates. It is almost always found only in plants, particularly vegetables, fruits, whole grains, nuts, and legumes (beans and peas). (One exception is chitosan, a dietary fiber made from shellfish skeletons.) Fiber cannot be digested but passes through the intestines, drawing water with it and is eliminated as part of feces content. The following are specific advantages from high-fiber diets (up to 55 grams a day):

  • Studies suggest that diets rich in fiber from whole grains reduce the risk for type 2 diabetes. Sources include whole grain breads, brown rice, and bran.

  • Insoluble fiber (found in wheat bran, whole grains, seeds, nuts, and fruit and vegetables) may help achieve weight loss. (It should be noted that nuts may be particularly beneficial for the heart by lowering LDL and total cholesterol without increasing triglycerides.)

  • Soluble fiber (found in dried beans, oat bran, barley, apples, citrus fruits, and potatoes), has important benefits for the heart, particularly for achieving healthy cholesterol levels and possibly benefiting blood pressure as well. Simply adding breakfast cereal to a diet appears to reduce cholesterol levels. A new form of barley may have three times the soluble fiber as oats and, in one study, was more effective than oats in controlling blood glucose and insulin. People who increase their levels of soluble fiber should also increase water and fluid intake.
Fiber supplements, such as Metamucil, Fiberall, and Perdiem do not appear to achieve the same benefits as foods naturally high in soluble fiber. Glucomannan, a natural high fiber powder obtained from a root, however, is showing promise in helping control blood glucose levels, cholesterol, and blood pressure.



Simple Carbohydrates (Sugar). No difference appears to exist between complex carbohydrates and simple sugars in their ability to raise blood glucose levels and in diets. The recent evidence on carbohydrates does not mean that diabetics should overload on sugar. However, people with diabetes can now add sugar (ideally from fresh fruits) in higher amounts than previously thought.

Sugars are general one of two types:

Sugar itself, either as sucrose or fructose, adds calories, increases blood glucose levels quickly, and provides no other nutrients. People with diabetes should continue to avoid products listing more than 5 grams of sugar per serving, and even fruit intake should be moderate. If specific amounts are not listed, patients should avoid products with either sucrose or fructose listed as one of the first four ingredients on the label. [ See Box Artificial Sweeteners.]



Artificial Sweeteners

Artificial sweeteners include the following:

  • Saccharin (Sugar Twin, Sweet n'Low, Sucaryl, and Featherweight). Some previous studies found that large amounts of saccharin cause bladder cancer in rats, but the rats were fed huge amounts that do not apply to human diets. (Nevertheless, evidence suggests that those who have six or more servings per day may have an increased risk.)

  • Aspartame (Nutra-Sweet, Equal, NutraTase). Aspartame has come under scrutiny because of rare reports of neurologic disorders, including headaches or dizziness, associated with its use. It has been studied more intensively than any other food additive, however, and concern about any major health dangers is unfounded.

  • Sucralose (Splenda). Sucralose has no better aftertaste and works well in baking, unlike other artificial sweeteners.

  • Acesulfame-potassium (Sweet One and SwissSweet)

  • under consideration for approval include neotame and alitame, which are made from amino acids.


Protein

In general, experts recommend that proteins should provide 12% to 20% of calories. Some believe that anyone with diabetes other than pregnant women should restrict protein to about 0.4 grams for every pound of their ideal body weight, about 10% of daily calories. One gram of protein contains four calories. Protein is commonly recommended as part of a bedtime snack to maintain normal blood sugar levels during the night, although studies are mixed over whether it adds any protective benefits against nighttime hypoglycemia. If it does, only small amounts (14 grams) may be needed to stabilize blood glucose levels.

Reducing proteins may help slow the progression of kidney disease, and one 1999 study indicated that a strict-low protein diet may even delay the need for dialysis in patients with kidney failure. (It should be noted that a diet that is severely low in both protein and salt diet while coupled with high fluid intake increases the risk for hyponatremia, a rare condition that can cause fatigue, confusion, and, in extreme cases, can be life-threatening.)

Fish. Fish is still probably the best source of protein. It has many advantages:

At this time, most studies indicate that eating moderate amounts (one or two servings weekly) of fish offers the most benefits. Some studies found that very high amounts (five or six servings weekly) can be harmful. This risk may be due to the presence of mercury in many kinds of fish.

Soy. Soy is an excellent food:

Four ounces of tofu equals about eight to 13 grams of soy, and a soy burger contains about 18 grams. Powdered soy protein that contains at least 60 mg of isoflavones may provide similar benefits. Tablets of individual isoflavones found in soy, however, do not appear to offer any advantages. (Note: soy sauce contains only a trace amount of soy and is very high in sodium.) Of possible concern, a high intake of soy during pregnancy may have some adverse effect on the fetus, although only animal studies have suggested this. More research is important.

Meat. For heart protection, one 1999 study suggested that it didn't matter if you chose fish, poultry, beef, or pork as long as the meat was lean. (Saturated fat in meat is the primary danger to the heart.) The fat content of meat varies depending on the type and cut. It is best to eat skinless chicken or turkey; the leanest cuts of pork (loin and tenderloin), veal, and beef are nearly comparable to chicken in calories and fat in their effect on LDL and HDL levels. It should be noted, however, that even chicken and lean meat do not improve cholesterol levels, and, in terms of cardiac health, fish is a more desirable choice.

Fats and Oils

General Recommendations for Fat Intake. About two-thirds of cholesterol in the body does not come from cholesterol in food but is manufactured by the liver, its production stimulated by saturated fat (mostly found in animal products). The dietary key to managing cholesterol, then, lies in understanding fats and oils. When it comes to studying the effects of fat on the body, however, the problem is compounded by its complex nature. All fats and oils found in foods are made up of chains of molecules composed of carbon and glycerol called fatty acids and which are bound by hydrogen atoms. There are three major chains:

The oils and fats that people and animals eat are nearly always mixtures of all three fatty acids, but one type usually predominates.

In addition, there are three chemical subgroups of polyunsaturated fatty acids called essential fatty acids: they are the following:

To complicate matters, there are also trans-fatty acids. Most of these are not natural fats but are manufactured by adding hydrogen atoms, a process known as hydrogenation, to polyunsaturated fatty acids. These subgroups are being heavily researched for their specific effects on health.

All fats, both good ones and bad, add the same calories. In order to calculate daily fat intake, multiply the number of fat grams eaten by nine (one fat gram is equal to 9 calories, whether it's saturated or unsaturated) and divide by the number of total daily calories desired. One teaspoon of oil, butter, or other fats equals about five grams of fat.

Although there is much controversy on the overall effects of fat on health, virtually all experts strongly advise limiting intake of saturated fats and trans-fatty acids (found in hard margarine, commercial baked goods, and fast foods). Other fatty acids, however, appear to offer benefits.

Harmful Fats. Reducing consumption of saturated fats and trans-fatty acids is the first essential step in managing cholesterol levels through diet.

Beneficial Fats and Oils. It should be noted that some fat is essential for health, and fat is essential for healthy development in children. Public attention has mainly focused on the possible benefits or hazards of monounsaturated (MUFA) and polyunsaturated (PUFA) fats.

Studies, however, do not all agree on their effects. Researchers are most interested in the smaller fatty-acid building blocks contained in both oils, which may have more specific effects on lipids. Three important fatty acids are the essential fatty acids omega-3, omega-6, and omega-9.

Research suggests that our current Western diet contains an unhealthy high ratio (10 to 1) of omega-6 to omega-3 fatty acid. Omega-9 fatty acids may also contain chemicals that block harmful factors found in omega-6 fatty acids. Researchers are finding then that the most benefits may be found in mixture of all three fatty acids found in both poly- and monounsaturated oils, but in modest amounts that do not add too many calories.

Fat Substitutes. Fat substitutes added to commercial foods or used in baking deliver some of the desirable qualities of fat, but do not add as many calories. They include the following:

People should try to limit even reduced-fat foods and fat substitutes in their diets. Although one might believe that eating reduced-fat or fat substitute products means consuming fewer calories, this is often not the case. Many commercial, lowered-fat products have extra calories from sugar and other carbohydrates. A study has found that people who consume foods that contain fat substitutes do not learn to dislike fatty foods, while people who learn to cook using foods naturally lacking or low in fat eventually lose their taste for high fat diets.

Some Examples of Healthy Foods

Foods

Phytochemicals and Carotenoids

Vitamins and other valuable food components

Benefits

Apples

Flavonoids



May have activity against certain cancers (lung). Also may help maintain healthy cholesterol.

Beans

Flavonoids

Folate, iron, potassium, and zinc.

Some experts believe beans are the perfect food.

Berries, all kinds of dark colored

Ellegic Acid

Vitamin C, minerals

May protect the aging brain. (In one study blueberries were most effective.)

Broccoli (also kale, Brussels sprouts, cauliflower)

Flavonoids, isothiocyanates, lutein, beta and alpha carotene

Vitamin C, folate, fiber, and selenium

Anticancer properties. Protective against heart disease and stroke.

Carrots and other bright yellow vegetables

Lutein, beta carotene and other provitamin A carotenoids.

Vitamin A (converted from carotenoids), Vitamin C

Protects eyes, lungs. (Cooking carrots may increases the potency of food nutrients.)

Eggs

lutein

Many B vitamins, vitamin A, vitamin D

Although egg yolks are high in cholesterol, very little of it has a negative effect on people with normal levels. And the health benefits of eggs are now known to be very high. (People with diabetes or those with high cholesterol should restrict eggs, however.)

Fish, oily (mackerel, salmon, sardines)



Vitamin B3, B12. Essential fatty acids, selenium

Heart and brain protective.

Garlic

Allium (organosulfurs)



Possibly protective against certain cancers, heart diseases, and infection. Heating garlic can reduce benefits. Allowing crushed fresh garlic to stand 10 minutes before heating, however, may preserve beneficial chemicals while cooking.

Ginger

Zingiberaceae



Cancer fighting properties.

Grains (whole)

Lignans (phytoestrogens)

Vitamin B, Selenium (important antioxidant mineral), fiber, folate

May help reduce the ability of cancer cells to invade health tissue.

Grapes, including purple grape juice, and red wine

Flavonoids, (resveratrol, quercetin and catechin)



Fight heart disease and cancer.

Nuts



Vitamin E, Vitamin B1, Essential fatty acids, folate

Protects the heart and may help prevent stroke.

Onions

Flavonoids, allium (organosulfurs)



May have activity against certain cancers (lung).

Oranges

Monoterpenes

Vitamin C, folate, potassium

Many health benefits. Increases HDL levels.

Potatoes (Sweet)



Vitamin C, vitamin E, vitamin A

Many health benefits.

Soy

Isoflavones (phytoestrogens), flavonoids, phytosterol, phytate, saponins



May have effects similar to estrogen, including maintaining bone and benefiting the heart. May also be protective against prostate cancer and possibly other cancers. More studies are needed. (Note: of some concern is one study reporting more mental decline in people who consume greater amounts of tofu.)

Spinach and other dark green leafy vegetables

Zeaxanthin, Beta carotene,

Vitamin C, folate, Vitamin A (converted from carotenoids)

Protects lungs and brain.

Tea (Green tea has reported best benefits)

Flavonoids



Cancer fighting properties, particularly in green tea. Black tea does not appear to have these particular benefits. Both black and green tea are heart protective and may protect against stroke.

Tomatoes

Lycopene, Flavonoids

Vitamin C, biotin, minerals

Studies link to reductions in prostate and other cancers. Infection fighters.



The story on cholesterol found in the diet is not entirely straightforward. Cholesterol is found only in animal tissues, with high amounts occurring in meat, dairy products, egg yolks, and shellfish. The American Heart Association recommends no more than 300 mg of cholesterol per day. One study estimated, however, that reducing dietary cholesterol intake by 100 mg/day would only produce a 1% decrease in cholesterol levels. Of note, however, are studies indicating that although dietary cholesterol itself does not appear to increase the risk for heart disease in most individuals, people with diabetes, especially type 2, may be an exception. Until more research is done, they should consider avoiding eating eggs or other high-cholesterol foods (such as shrimp) more often than once a week.

Vitamins and Supplements

Antioxidant Properties. Currently, the most important benefit claimed for vitamins A, C, E, and many of the carotenoids and phytochemicals is their role as antioxidants, which are scavengers of particles known as oxygen-free radicals (also sometimes called oxidants). These chemically active particles are by-products of many of the body's normal chemical processes. Their numbers are increased by environmental assaults, such as smoking, chemicals, toxins, and stress. In higher levels, oxidants can be very harmful:

Antioxidant vitamins (A, C, and E), carotenoids, and many phytochemicals can neutralize free radicals and may reduce or even prevent some of their damage. Unfortunately, although it is clear that vitamins are required to prevent deficiency diseases, the possible benefits of higher-dose supplements are still unproven in most cases. To date, there is no strong evidence that antioxidant supplements offer any real protection. In some cases, high doses may be harmful. [ See Box Special Warning on Antioxidant Vitamins .]

Vitamin E. Vitamin E may prevent blood clots and the formation of fatty plaques and cell proliferation on the walls of the arteries. Long-term studies of people who take vitamin E supplements, however, are mixed:

Different vitamin E compounds, such as gamma tocopherol or tocotrienol may have benefits that the standard synthetic supplement (dl alpha tocopherol) does not. Studies are fairly consistent in indicating that eating foods rich in natural vitamin E may be protective.

Vitamin C. Vitamin C appears to maintain blood vessel flexibility and to improve circulation in the arteries of smokers. Generally, such findings have occurred in the laboratory. In one English 2001 study, people whose diets were rich in foods that elevated levels of vitamin C in their blood were at lower risk for heart disease, overall poor health, and death. There is no evidence, however, that supplements of vitamin C offer any actual protection against heart disease, and a major 2001 study found no benefits for the heart in high-risk patients.

B Vitamins. Several important studies have demonstrated a link between deficiencies in the B vitamins folate, B6, and B12 and elevated blood levels of homocysteine, an amino acid believed to be a risk factor for atherosclerosis. Both B12 and folate reduce homocysteine levels, although it is not yet clear if this effect is actually protective against heart disease. (Homocysteine may simply be a marker, not a cause, of heart disease.) Major studies are under way and early results of small studies are promising. A 2001 study, for example, reported lower rates of heart disease in populations that had high levels of folate and B12 regardless of any other risk factors. Dosage of 0.8 mg/day of folic acid appears to be necessary for reducing homocysteine levels. Folate also improves blood flow through the arteries, which may be of equal or greater importance for the heart than its effect on homocysteine.

Another important B vitamin is niacin (Vitamin B3), which has special benefits for patients with unhealthy cholesterol levels. There has been some concern that high levels may actually have adverse effects on glucose control. [See also the Well-Connected report Cholesterol.]

Lipoic Acid. Lipoic acid, a coenzyme with antioxidant properties, is receiving some attention. In one very preliminary study, researchers found that treatment with lipoic acid may be more kidney protective than high doses of both vitamin C and E. More research is needed.

Minerals

Magnesium. Magnesium deficiency may have some role in insulin resistance and high blood pressure. One study reported that low magnesium levels as measured in blood tests were associated with a higher risk for type 2 diabetes in whites but not in African Americans. Dietary intake of magnesium, however, did not appear to play any role in increasing or reducing risk for either population group. It is more likely that diabetes may cause magnesium loss. No supplements are recommended at this time for patients with adequate levels of magnesium. For people taking diuretics for high blood pressure, extra potassium may be needed, but in other cases, including certain kidney problems, an overload of potassium may occur, so no regular supplements are recommended without consulting a physician.

Chromium. Some studies have reported an association between deficiencies in the mineral chromium and a higher risk for type 2 diabetes. Studies on fat rats that were given chromium reported improvement in insulin sensitivity and glucose metabolism. Studies on human type 2 patients, however, reported few benefits and some adverse side effects.

Zinc. Many type 2 diabetics are also deficient in zinc; more studies are needed to establish the benefits or risks of taking supplements. Zinc has some toxic side effects, and some studies have associated high zinc intake with prostate cancer.

Salt and Sodium

Salt can raise blood pressure, and people with diabetes should limit salt intake, particularly if they have hypertension, are overweight, or both. Overweight people who have a high sodium intake may be at increased risk for death from heart disease. High salt diets in people who are sensitive to its effects may harm the kidney and brain, even independently of high blood pressure. Restricting salt also enhances the benefits of nearly all standard antihypertensive drugs by reducing potassium loss, and may help protect against kidney disease in patients who are also taking calcium-blocker drugs.

Although it is not clear whether restricting sodium adds any benefits for most people whose diets are rich in fruits, vegetables, and low-fat dairy products and who are not salt-sensitive, it is always wise to aim for a maximum of 2,000 mg sodium intake. Simply eliminating table and cooking salt can be beneficial. Salt alternatives, such as Cardia, containing mixtures of potassium, sodium, and magnesium are now available but are costly. It should be noted, however, that about 75% of the salt in the typical American diet comes from processed or commercial foods, so the benefits of table-salt substitutes are likely to be very modest. Some sodium is essential to protect the heart, but most experts agree that the amount is significantly less than that found in the average American diet.

Caffeine and Alcohol

Alcohol. Studies in 1999 and 2000 have suggested that light to moderate alcohol intake (one or two glasses a day) may have specific benefits for people with type 2 diabetes. In one it was associated with a reduced risk for death from heart disease, and in the other it protected against type 2 diabetes itself. Red wine particularly appears to have health benefits. In one study, drinking red wine at meals even reduced blood glucose levels in some cases. (Alcohol itself had no effect on blood glucose or insulin.) In those taking insulin or sulfonylureas, however, alcohol may cause a hypoglycemic reaction, of which the drinker may not be aware. Pregnant women or those at risk for alcohol abuse should not drink alcohol.

Caffeinated Beverages.

Of note, a 1999 study reported an effect of caffeine on the brain that has implications for diabetes: it reduces blood flow in the brain even in the presence of sufficient glucose. People with diabetes who drink even two or three cups of coffee may actually believe they are hypoglycemic when their blood glucose levels are normal. One study suggested that this effect may actually help increase awareness of hypoglycemia in some people who have difficulty recognizing its symptoms.

WHAT ARE THE WEIGHT CONTROL AND DIETARY APPROACHES FOR TYPE 2 DIABETES?

Weight control is an especially important part of the management of type 2 diabetes. A 1999 analysis of 2,800 individuals who had lost at least 30 pounds and maintained the weight loss for more than year reported the following: about 55% had been involved in a formal weight loss program, 20% succeeded with liquid diets, only 4.3% used medications, and 1.3% had surgery. And, importantly, 80% reported that they exercised more often and more vigorously than with previous attempts. [For more detailed information see the Well-Connected report, Obesity.]

General Approach to Weight Loss and Maintenance

Life long changes in eating habits, physical activity, and attitudes about food and weight are essential to weight management. The following offer some general suggestions for dieters:

Calorie Restriction. Calorie restriction has been the cornerstone of obesity treatment. The standard dietary recommendations for losing weight are the following:



Warning on Extreme Diets

Extreme diets of less than 1,100 calories carry health risks and are often followed by bingeing or overeating and a return to the obese state. Such diets often have insufficient vitamins and minerals, which must then be taken as supplements. Most of the initial weight loss is in fluids. Later, fat is lost, but so is muscle, which can account for more than 30% of the weight loss. No one should be on severe diets longer than 16 weeks or fast for more than two or three days. Severe dieting has unpleasant side effects, including fatigue, intolerance to cold, hair loss, gallstone formation, and menstrual irregularities. There have been rare reports of death from heart arrhythmias when liquid formulas did not have sufficient nutrients. Of note, those whose diets include a high intake of fluids and much reduced protein and sodium are at risk for hyponatremia, which can cause fatigue, confusion, dizziness, and in extreme cases, coma.



Low-Fat High-Complex Carbohydrates. Some studies suggest that replacing foods high in fats and sugars with low-fat complex carbohydrates (fruits, vegetables, and whole grains) may be more effective for weight control than calorie counting. In one study, people with type 2 diabetes who were unable to exercise achieved significant reductions in blood glucose levels and body weight with a strict vegetarian (no dairy or meat) low-fat diet. Consuming insoluble fiber (found in wheat bran, whole grains, seeds, and fruit and vegetables) may be an important component for weight loss from this diet. (Soluble fiber does not appear to have much effect on weight.) Some dietary fat is essential; such fats should be derived from monounsaturated oils and fish.

Still, the high-carbohydrate low-fat diet has come under scrutiny. Some diabetics may have problems with cholesterol and triglyceride levels when carbohydrates constitute over 50% of the diet. If triglycerides are high, carbohydrates should be reduced to 45%. It should be noted that replacing fatty foods, such as cakes, cookies, and chips, with their commercial "low-fat" counterparts does not constitute a low-fat diet. These foods generally contain more sugar and hence calories, not to mention other ingredients which have virtually no nutritional value. In fact, a 2002 study suggested that increased sugar consumption may reduce levels of HDL cholesterol, the so-called good cholesterol.

High-Protein Low-Carbohydrate Diet. High-protein diets can be very effective in producing short-term weight loss, but their long-term effects on health are in question. They may be particularly harmful for people with diabetes. Such diets are currently popular and include the Zone, Dr. Atkins, Protein Power, Sugar Busters, and Dr. Stillman.

High-Fat Low-Carbohydrate Diet. Some studies suggest that replacing carbohydrate calories with monounsaturated fats (such as olive oil) does not harm cholesterol levels and may improve glucose control. (Calories must still be restricted, however.)

Structured Snacks

Low-calorie snack packages (Lean on Me, Level Best) are being developed for people with type 2 diabetes that contain supplements (such as psyllium, barley, fructose, green-tea extract, chromium picolinate and 5-http) associated with claims for improving factors that affect the heart and diabetes. Although promising, these packages have not been clinically studied, and patients should be warned that their long-term risks and benefits are not known.


WHAT ARE THE GENERAL GUIDELINES FOR HEART-HEALTHY DIETS?

Any diet should be healthy for the heart. Currently, there is much controversy over the best balance of carbohydrates, fats, and protein. The three major cholesterol reduction diets are the following:

[For more detail see Well-Connected Report #43 Heart-Healthy Diet.]

American Heart Association Diet Recommendations

AHA Diet is in two stages, depending on heart disease risk.

Recommendations for People with Normal Risk.

Recommendations for People with Health Problems. Individual diet plans should be developed that take into consideration the individuals specific problems, including lipids, blood pressure, and the presence of diabetes. So, for patients with elevated LDL cholesterol and a history of heart disease, the following are recommended:

Mediterranean Diet

The Mediterranean diet is rich in heart-healthy fiber and nutrients, including omega-3 fatty acids and antioxidants. The diet recommends the following:

Positive Arguments. Evidence is increasingly strong on the heart-protective properties of this diet and studies are reporting that it is more beneficial than the AHA approach in lowering total and LDL cholesterol and triglyceride levels. It appears to have little, either positive or negative, effect on, HDL levels. Studies report the following:

Negative Arguments. Weight gain from the high intake of fats can be a problem with this diet, however, in anyone who has to watch calories. Other concerns with the Mediterranean diet are reduced iron levels and possible calcium loss resulting from consumption of fewer dairy products.

The Ornish Program and Severely Fat-Restricted Diets

The Ornish program limits saturated fats as much as possible, reduces total fat to 10%, and increases carbohydrates to 75% of calories. It is a very effective but demanding regimen:

People on low fat diets should consume a wide variety of foods and take a multivitamin if appropriate.

Positive Arguments. Low-fat diets that are high in fiber, whole grains, legumes, and fresh produce offer health advantages in addition to their effects on cholesterol.

Negative Arguments. The American Heart Association argues that the Ornish program is so difficult to maintain that it will not benefit many people. The comparison study showing the advantage of the Ornish over the Step 2 diet, in fact, was very small because few participants could sustain the efforts needed to fulfill the requirements of the Ornish program for five years.

Some experts argue that it is not clear whether fat-restriction or the other elements in the program, exercise and stress reduction, are mainly responsible for its benefits.

Many people who reduce their fat intake do not consume enough of the basic nutrients, including vitamins A and E, folic acid, calcium, iron, and zinc. People on low-fat diets should consume a wide variety of foods and take a multivitamin if appropriate.

The DASH Diet

A diet known as Dietary Approaches to Stop Hypertension (DASH) is now recommended as an important step in managing blood pressure. This diet is not only rich in important nutrients and fiber but also includes foods that contain two and half times the amounts of electrolytes, potassium, calcium, and magnesium, as are found in the average American diet. It makes the following recommendations:

In one study, after eight weeks on the diet, subjects from a broad range of backgrounds experienced a significant reduction in blood pressure. A 2000 study reported that a combination of the DASH diet and salt restriction is very effective in reducing blood pressure. (Each approach has positive benefits, but the combination is best.) Some individuals should take particular measures to restrict salt. [For more information see the Well-Connected report on High Blood Pressure.] [For detailed information see the Well-Connected report, Heart-Healthy Diet .]

WHAT ARE THE DIABETIC EXCHANGE LISTS?

General Guidelines for Exchange Lists

The objective of the exchange lists is to maintain the proper balance of carbohydrates, proteins, and fats throughout the day. The exchange lists can be obtained by calling or writing the American Diabetes Association. [ See Where Else Can Help Be Obtained for Diabetes Diet?]

In developing a menu, patients must first establish with a doctor or dietitian their individual dietary requirements, particularly the optimal number of daily calories and the proportion of carbohydrates, fats, and protein. The exchange lists should then be used to set up menus for each day that fulfill these requirements.

The following are some general rules:

Exchange List Categories

The following are the categories given on the exchange lists:

Starches and Bread. Each exchange under starches and bread contains about 15 grams of carbohydrates, 3 grams of protein, and a trace of fat for a total of 80 calories. A general rule is that a half cup of cooked cereal, grain, or pasta equals one exchange and one ounce of a bread product is one serving.

Meat and Cheese. The exchange groups for meat and cheese are categorized by lean meat and low fat substitutes, medium-fat meat and substitutes, and high-fat. High fat exchanges should be used at a maximum of 3 times a week. Fat should be removed before cooking. Exchange sizes on the meat list are generally one ounce and based on cooked meats (three oz of cooked meat equals 4 oz of raw meat).

Vegetables. Exchanges for vegetables are 1/2 cup cooked, 1 cup raw, and 1/2 cup juice. Each group contains 5 grams of carbohydrates, 2 grams of protein, and between 2 to 3 grams of fiber. Vegetables can be fresh or frozen; canned vegetables are less desirable because they are often high in sodium. They should be steamed or microwaved without added fat.

Fruits and Sugar. Sugars are now included within the total carbohydrate count in the exchange lists. Sugars still should not be more than 10% of daily carbohydrates. Each exchange contains about 15 grams of carbohydrates for a total of 60 calories.

Milk and Substitutes. The milk and substitutes list is categorized by fat content similar to the meat list. A milk exchange is usually one cup or 8 oz. For those who are on weight-loss or low-cholesterol diets, the skim and very low-fat milk lists should be followed, and the whole milk group avoided. Others should use the whole milk list very sparingly. All people with diabetes should avoid artificially sweetened milks.

Fats. A fat exchange is usually 1 teaspoon but it may vary. People, of course, should avoid saturated and trans-fatty acids and choose polyunsaturated or monounsaturated fats instead.

Number of Exchanges per Day for Various Calories Levels
Calories

1200

1500

1800

2000

2200

Starch/Bread

5

8

10

11

13

Meat

4

5

7

8

8

Vegetable

2

3

3

4

4

Fruit

3

3

3

3

3

Milk

2

2

2

2

2

Fat

3

3

3

4

5



WHAT IS CARBOHYDRATE COUNTING AND BLOOD GLUCOSE CONTROL?

The Carbohydrate Counting System

The system called carbohydrate counting is based on two premises:

In other words, the amount of carbohydrates eaten (rather than fats or proteins) will determine how high blood sugar levels will rise. There are two options for counting carbohydrates: advanced and simple. Both rely on the collaboration with a physician, dietitian, or both. Once the patient learns how to count carbohydrates and adjust insulin doses to their meals, many find it more flexible, more accurate in predicting blood sugar increases, and easier to plan meals than other systems.

Creating the Plan

The basic goal is to balance insulin with the amount of carbohydrates eaten in order to control blood glucose levels after a meal. The steps to the plan are as follows:

The patient must first carefully record a number of factors that are used to determine the specific requirements for a meal plan based on carbohydrate grams:

The patient works with the dietitian for two or three 45 to 90 minute sessions to plan how many grams of carbohydrates are needed. There are three carbohydrate groups:

One serving from each group should contain between 12 and 15 carbohydrate grams. (Patients can find the amount of carbohydrates in foods from labels on commercial foods and from a number of books and web sites.)

The dietitian creates a meal plan that accommodates the patient's weight and needs, as determined by the patient's record, and makes a special calculation called the carbohydrate to insulin ratio . This ratio determines the number of carbohydrate grams that a patient needs to cover the daily pre-meal insulin needs.

Eventually, patients can learn to precisely adjust their insulin doses to their meals.

It should be noted that patients who choose this approach must still be aware of protein and fat content in foods. They may add excessive calories and saturated fats. Patients must still follow basic healthy dietary principles.

WHAT IS THE GLYCEMIC INDEX?

Description of the Glycemic Index

Not all carbohydrates are equal in how quickly or slowly they raise blood glucose. Choosing carbohydrates that have a slower effect on blood glucose may help control the surge in blood glucose that occurs after meals (called postprandial hyperglycemia). A rating system called the glycemic index helps patients predict how quickly specific foods affect blood sugar. [ See Table The Glycemic Index of Some Foods, below.]

The following are some tips to remember in choosing this approach:

In addition to helping control blood glucose, diets rich in foods that have a low glycemic index appear to have added health benefits:

No one should use the glycemic index as a complete dietary guide, however, since it does not provide nutritional guidelines for all foods. It is simply an indication of how the metabolism will respond to carbohydrates eaten. Some experts believe it is too complicated to be practical and that simply tracking carbohydrates, eating healthily, and maintaining a healthy weight is sufficient.

The Glycemic Index of Some Foods Based on 100 = a Glucose Tablet.
BREADS



pumpernickel

49

rye

64

white

69

whole wheat

72

GRAINS



barley

22

sweet corn

58

brown rice

66

white rice

72

BEANS



soy

14

red lentils

27

kidney

33

chickpeas

36

baked

43

DAIRY PRODUCTS



milk

34

ice cream

38

CEREALS



oatmeal

53

All Bran

54

Swiss Muesli

60

Shredded Wheat

70

Corn Flakes

83

Puffed Rice

90

PASTA



spaghetti-protein enriched

28

spaghetti

38

macaroni

46

FRUIT



strawberries

32

apple

38

orange

43

orange juice

49

banana

61

POTATOES



sweet

50

yams

54

new

58

mashed

72

instant mashed

86

white

87

SNACKS



potato chips

56

oatmeal cookies

57

corn chips

72

SUGARS



fructose

22

refined sugar

64

honey

91

Note. These numbers are general values, but may vary widely depending on other factors, including if and how they are cooked and foods they are combined with.

WHAT NONDIETARY BEHAVIORS HELP CONTROL DIABETES?

Exercise

Diabetes, particularly type 2, is reaching epidemic proportions throughout the world as more and more cultures adopt Western dietary habits. Aerobic exercise is proving to have significant and particular benefits for people with both type 1 and type 2 diabetes.

Benefits of Exercise for People with Diabetes

Some Precautions for People with Diabetes Who Exercise

All people with diabetes should check with their physician before starting a program. The following are precautions for all people with diabetes:

Patients who are taking medications that lower blood glucose, particularly insulin, should take special precautions before embarking on a workout program.

WHERE ELSE CAN INFORMATION BE OBTAINED ON DIABETES DIETS?

American Diabetes Association, ATTN: Customer Service, 1701 Beauregard Street, Alexandria, VA 22311
Call (800-232-3472) or (800-DIABETES) or on the Internet (http://www.diabetes.org/)
This is the primary source for information on diabetes.


National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, Building 31, Room 9A04, 31 Center Drive, MSC 2560, Bethesda, MD 20892-2560. Call (301) 654-3327 or on the Internet (http://www.niddk.nih.gov/)
A source of information for research advances and clinical trials currently underway. For those who have relatives with diabetes and may be at risk and are interested in participating in a trial on prevention, call (800-Halt-DM-1).


Juvenile Diabetes Foundation, International, 120 Wall Street, 19th floor, New York, NY 10005. Call (212-785-9500) or call (800-JDF-CURE)
or on the Internet (http://www.jdfcure.com/)


National Eye Health Education Program, National Eye Institute, 2020 Vision Place, Bethesda MD 20892. Call 301-496-5248) or (800-869-2020)
or on the Internet (http://www.nei.nih.gov/ )


American Dietetic Association, 216 West Jackson Boulevard, Suite 800, Chicago IL 60606-6995. Call (312-899-0040) or on the Internet (http://www.eatright.org/)
This organization provides names of local dietitians and programs through their Dietitian Referral Hotline: Call (800-366-1655) from 9AM to 4PM.
For customized answers to food and nutrition questions:
Call (900-225-5267) charge is $1.95 for the first minute and $.95 for each additional minute.


US Food and Drug Administration, 5600 Fishers Lane, Rockville, MD 20857-0001. Call (888-INFO-FDA) or on the Internet (http://www.fda.gov/)


Well-reviewed software for managing diet and glucose control
(http://www.healthviewdiabetes.com/)


On the Internet:

Informational site for professionals
(http://www.diabetesincontrol.com/)

Children with Diabetes dietary page
(http://www.childrenwithdiabetes.com/d_08_000.htm)

Iowa State University Extension, Food and Nutrition Publications (http://www.extension.iastate.edu/pubs/fo1.htm)

International Food Information Council
(http://ificinfo.health.org/)

Nutrition Analysis Tool
(http://spectre.ag.uiuc.edu/~food-lab/nat/)

Diabetic Gourmet Magazine
(http://gourmetconnection.com/diabetic/)

For more information on soy, call the Soy Hotline (1-800-TALKSOY)
or visit the Soy Website (http://www.soyfoods.com)

For a Glycemic index of a number of foods, including commercial cereals
(http://www.mendosa.com/gilists.htm)

Good lists of fiber-rich foods
(http://www.slrhc.org/healthinfo/dietaryfiber/)

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Board of Editors

Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital

Stephen A. Cannistra, MD, Oncology, Associate Professor of Medicine, Harvard Medical School; Director, Gynecologic Medical Oncology, Beth Israel Deaconess Medical Center

Masha J. Etkin, MD, PhD, Gynecology, Harvard Medical School; Physician, Massachusetts General Hospital

John E. Godine, MD, PhD, Metabolism, Harvard Medical School; Associate Physician, Massachusetts General Hospital

Edwin Huang, MD, Gynecology, Harvard Medical School; Physician, Massachusetts General Hospital

Daniel Heller, MD, Pediatrics, Harvard Medical School; Associate Pediatrician, Massachusetts General Hospital; Active Staff, Children's Hospital

Paul C. Shellito, MD, Surgery, Harvard Medical School; Associate Visiting Surgeon, Massachusetts General Hospital

Theodore A. Stern, MD, Psychiatry, Harvard Medical School; Psychiatrist and Chief, Psychiatric Consultation Service, Massachusetts General Hospital

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