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Efficacy of Medical Nutrition Therapy: Are Your Patients Getting What They Need?

The year is 1797, and you have just been diagnosed with diabetes by John Rollo, the famous English Surgeon General of the Royal Artillery. For your meal plan, Dr. Rollo suggests a diet consisting of animal products “with an entire abstinence of every kind of vegetable matter.” A sample menu might have been: a mixture of lime water with milk and bread and butter for breakfast, plain blood pudding made with only blood and suet for lunch, and old, rancid meat and fat for supper, to be followed by opium for dessert.¹

The history of diabetes nutritional management reveals a wide spectrum of such unpalatable diets. From the all-carbohydrate diet of Artaeus the Cappadocian in 5 AD to the Fredrick Allen starvation treatment in 1912,¹ medical professionals have been searching for the most efficacious method of managing the nutrition of people with diabetes.

In the recent past, the most common method of nutrition counseling was the exchange list meal plan, with the efficacy reliant on how, when, and where the information had been presented. An often-used counseling technique, with less than optimum results, consisted of handing the patient a pre-printed diet in the doctor’s office at the time of diagnosis, with an arbitrarily set calorie level and the expectation that individuals would permanently tailor their lifestyles to fit the meal plan.

A study recently published by Franz and associates² supports the medical and economical benefits of diabetes medical nutrition therapy (MNT) when provided by registered dietitians who are also certified diabetes educators with 5–13 years of experience in the field of nutrition and diabetes. A prospective, randomized controlled clinical trial of two levels of MNT for non-insulin-dependent diabetes mellitus (NIDDM) was conducted. Basic nutrition care, which consisted of a single visit, was compared to practice guideline nutrition care, which consisted of an initial visit with a dietitian followed by two visits during the first 6 weeks of the study period.

The study compared medical outcomes of fasting plasma glucose, glycated hemoglobin, and serum lipid levels, and clinical outcomes including weight, body mass index, waist-to-hip ratio, and changes in medical therapy. Study results at 6 months indicated improved glycemic control and weight loss in both nutrition intervention groups and improved cholesterol values in the practice guidelines nutrition care group. The study concluded that MNT was effective in improving medical and clinical outcomes.

Delahanty and Halford³ found lower HbA1c values in the Diabetes Control and Complications Trial (DCCT) that were not associated with a specific meal plan or diet, but with the specific nutrition behaviors outlined in Table 1. Compliance with the meal plan, adjustment of insulin dose on the basis of expected food intake, and appropriate treatment of hypoglycemia should all be considered. Interestingly, no specific meal plan was identified as beneficial, but rather any nutrition intervention system that incorporated these nutrition behaviors resulted in lower HbA_1c values.

The 1994 version of the American Diabetes Association (ADA) Nutrition Recommendations and Principles for People with Diabetes Mellitus recognizes the benefit of individualizing nutritional care and that a “one-size-fits-all” approach to modifying eating habits cannot be effective.₄

Many patients come to our clinic stating that they avoid sweets but cannot understand why their blood glucose levels are so variable. Individualized nutritional counseling by a registered dietitian experienced in diabetes management or a diabetes nutrition specialist can provide pertinent insight into food-related blood glucose problems. Educating individuals about how various nutrients (carbohydrate, protein, fat, alcohol) affect blood glucose can minimize many blood glucose fluctuations (see Table 2).

Food intake records, blood glucose logs, and exercise records can be useful tools to individualize strategies for coordinating eating patterns with diabetes medications and physical activity. Sometimes, just teaching an individual with diabetes that 100% of all carbohydrate food (whether from breads and starches or sweets and sucrose) is converted to glucose can prove beneficial.

Fifty to 60% of protein is typically utilized as blood glucose within 3–6 hours after ingestion. Fat has a limited direct effect on blood glucose, with 10% metabolized as blood glucose, usually about 8 hours after ingestion. Additionally, fat will slow the absorption of carbohydrate, occasionally resulting in hypoglycemia following a high-fat meal.

Effective medical nutrition counseling includes a comprehensive evaluation that considers type of diabetes, lipid profile, blood pressure, renal function, and weight history and goals, as well as lifestyle, schedule, and personal food preferences. Individual food choices are driven not only by the physiological requirements of nutrients, but also by the psychosocial relationship of food and the process of eating. This complex relationship often makes MNT the most challenging component of diabetes management.

Table 3 outlines many issues related to nutrition goal outcomes that need to be considered when planning appropriate MNT. When considering the appropriate MNT approach for an individual with diabetes, particular attention needs to be given to usual food choices, food likes and dislikes, learning style, cultural issues, and socioeconomic status. Consider all of these factors when implementing guidelines for a specific individual.

1. Maintaining near-normal blood glucose levels by balancing food intake with insulin (either endogenous or exogenous) or oral glucose-lowering medications and activity levels.

2. Achieving optimal lipid levels. The guidelines provided by the Adult Treatment Panel II and the Expert Panel on Blood Cholesterol Levels in Children and Adolescents of the National Cholesterol Education Program5 levels also apply to people with diabetes mellitus. Nutrition intervention plays a significant role in achieving recommended lipid levels.

3. Providing adequate calories for attaining reasonable weights for adults, fostering normal growth and development rates for children and adolescents, and meeting increased metabolic needs during pregnancy and lactation or recovery from catabolic illness. Reasonable weight for adults is defined by considering weight history and is a weight that both the individual and health professional feel is attainable and can be maintained over the long term.

4. Preventing, delaying, or treating nutrition-related risk factors and complications. Nutrition assessment and intervention are essential to reduce risk factors related to obesity, dyslipidemia, and hypertension (see Table 4).

5. Improving overall health through optimal nutrition. This seems to be an obvious goal of nutrition intervention, but some individuals become so focused on improving blood glucose that they lose sight of the importance of good nutrition.

Table 4 provides an overview of recommendations ideally designed to be preventive nutrition strategies.³

Table 4. Medical Nutrition Therapy Nutrient Recommendations
Nutrient	Recommendation	Comments
Protein Sources: chicken, fish, meat, eggs, milk, tofu, nuts, peanut butter	10-20% of total calories should come from protein sources.	• Research indicated protein needs are similar for people with or without diabetes. •With onset of nephropathy, limit protein to adult RDA (0.8 g/kgday). •Some research studies suggest vegetable protein may not be as harmful to the kidneys as animal protein.
Carbohydrate Sources: starch (grains, bread,pasta, rice, potato, beans) milk, fruit, vegetables, sugar, honey, jam, molasses, etc.	80–90% of calories are divided between carbohydrate and fats based on individual risk factors and needs. Depending on nutritional assessment and medical nutritional therapy goals, this generally equates to 45–60% of total calories from carbohydrate.	• Total carbohydrate intake has greater impact onblood glucose control than source of carbohydrate, i.e. whether from complex carbohydrate or sucrose. • Sucrose and sucrose-containing foods should be consumed within the context of a healthful diet. These foods are often high in total carbohydrate and fat and low in vitamins and minerals. • Individuals can be taught to substitute sucrose- containing foods for other carbohydrate foods in their meal plan.
Fat Sources: monounsaturated: olive and canola oils, avocado, nuts polyunsaturated: safflower, sunflower, corn, and soy oils saturated: butter, lard, shortening animal fats, cocunut, and palm oils.	60-70% of total calories should be divided between monounsaturated. fats and carbohydrates. Up to 10% of calories should be from polyunsaturated fats. Less than 10% of total calories should be from saturated fats. Depending on nutritional assessment, total fat intake equates to 25–35% of total calories.	• Individuals with diabetes, normal lipid levels, and reasonable body weight should limit total fat to < 30% of total calories and < 300 mg of dietary cholesterol per day. • If obesity and weight management are the primary issues, reducing total fat to reduce total calories and increasing exercise should be considered. • If low density lipoprotein cholesterol is the primaryconcern, progression to National Cholesterol Education Program step II dietary guidelines (< 7% of total calories from saturated fat and < 200 mg cholesterol per day) should be implemented. • Guidelines for reducing cardiovascular risk are emphasized—nobody should exceed 10% of total calories from saturated fat. • If elevated triglyceride and very low density lipoprotein cholesterol are the primary concerns, a moderate increase in monounsaturated fat intake, with < 10% of total calories from saturated fat, and a more moderate (slight decrease) in carbohydrate can be tried. Some studies have shown that a diet with increased total fat from monounsaturated fats can lower plas- ma triglycerides, glucose, and insulin levels more than a high-carbohydrate diet in some individuals. In individuals with triglyceride > 1000, reduction of all types of dietary fats to reduce levels of plasma dietary fat in the form of chylomicrons may be implemented.
Fiber	20-35 grams per day --same recommendation as for individuals without diabetes.	• Research suggests that, in the amounts typically consumed, fiber intake has very little impact on blood glucose levels.
Sodium	Same as for general population: < 3000 mg per day. If hypertensive, individuals should reduce sodium intake to are more salt-sensitive. < 2400 mg per day. Food selection guidelines: < 400 mg sodium per singleserving of food; < 800 mg sodium per entree or convenience meal.	• There is an association between hypertension and both IDDM and NIDDM, with an increased risk for people with NIDDM who are obese. There is also evidence that individuals with NIDDM
Alcohol	Insulin users: Limit to 2 drinks per day and so not cust back on food. Non-insulin users: Substitutes alcohol for fat:1 drink = 2 fat exchanges	• Abstinence is recommended for those with a history of abuse and during pregnancy. • Drink only with food. Alcohol can lead to hypoglycemia via inhibition of gluconeogenesis. • Limit for weight loss and elevated triglycerides.
Mononutrients	The vitamin and mineral needs of people who are healty appear to be adequately met by the RDAs, which include a generous safety factor.	• Individuals who are at greatest risk for vitamin/ mineral deficiency include those on extreme weight loss diets, strict vegetarians, the elderly, pregnant or lactating women, those taking medications known to alter micronutrient metabolism, people with poor glycemic control (i.e., glycosuria), people with malabsorption disorders, and people with congestive heart failure or myocardial infarction.

A plethora of approaches to MNT exist for diabetes nutrition specialists to use when developing a nutrition treatment plan. Any approach selected should strive to prioritize the goals as outlined in the 1994 ADA Nutrition Recommendations.⁴

For effective therapy to occur, individuals with diabetes are assessed and the goals for MNT are prioritized. All team members, especially the individual with diabetes, must have ownership of these goals. The prioritized goals receive the emphasis when developing the nutrition treatment plan. Continuous assessment is made to evaluate the importance of these and other goals, as additional medical and psychosocial data become available.

Modern diabetes nutrition therapy no longer “puts people on diets,” but instead develops nutrition treatment plans around an individual’s current lifestyle, food choices, and habits. While MNT is provided by the diabetes nutrition specialist, the effectiveness hinges on the support of the entire diabetes management team. Physicians must understand the nutrition approaches an individual is using and reinforce this therapy when interacting with the individual.

Nutrition Survival Skills
Effective diabetes MNT begins with communicating nutrition survival skills. These are defined as those skills necessary to avoid emergency situations. Table 5 outlines basic nutrition survival skills for insulin-dependent diabetes mellitus (IDDM) and for individuals with NIDDM using insulin or oral hypoglycemic agents. Before MNT is initiated, providers initially responsible for patients’ diabetes management, whether nurse educators, diabetes nutrition specialists, or physicians, need to be assured that patients understand basic nutrition survival skills. These skills should be conveyed to patients in the first education sessions.

One of these skills includes knowledge of causes and symptoms and appropriate treatment of hypoglycemia. Individuals should identify their typical symptoms when experiencing hypoglycemia. Treatment should come in the form of carbohydrates with a high percentage of glucose. See Table 6 for specific examples of appropriate treatment. Avoid treating hypoglycemia with a food high in fat, such as ice cream or chocolate bars. The fat in these foods delays the absorption of the carbohydrate and slows the return of euglycemia.

Knowledge of the pharmokinetics of insulin or the oral hypoglycemic agent regimen is essential for safe management of diabetes. Peaks and duration of medication must be planned around an individual’s typical schedule, with special consideration to meal timing. Individuals must understand the peak and duration activity of their insulin or oral hypoglycemic agent to prevent hypoglycemia if a usual meal or snack is missed or additional activity or exercise occurs.

The safe use of alcohol must also be reinforced with all individuals taking insulin or oral hypoglycemic agents. Alcohol inhibits gluconeogenesis and interferes with the counterregulatory hormone response needed to prevent hypoglycemia. Specific guidelines regarding alcohol are outlined in Table 5. These should be provided to all appropriate individuals. The need to eat a meal or substantial snack while drinking alcohol should also be discussed.

Approaches To MNT
MNT can be divided into three categories: 1) task, 2) guideline, and 3) meal planning approaches. Depending on the type of diabetes and the medical and nutritional goals determined by the patient and the diabetes management team, specific approaches are used. Intervention may include only one, or a combination of several of the approaches discussed below.

Task approaches. Task approaches to MNT are appropriate for use in management of IDDM and NIDDM. The tasks are usually straightforward and objective responsibilities agreed to by providers and patients. Table 7 outlines a variety of nutrition task approaches with their benefits and drawbacks. These approaches provide individuals with guidance to complete a specific task, which will encourage modification of food choices or reinforce positive components of current food choices. The tasks are easily reviewed by patients and diabetes nutrition specialists to assess compliance.

One example of using the task approach would be an individual saving and reviewing itemized grocery re-ceipts. Review of receipts facilitates assessment of food choices while shopping. Additionally, there can be follow-up phone consultations or use of a facsimile machine to review performance and modify or reinforce tasks as necessary. This approach is an effective method of increasing accessibility for provider and patient between clinic visits.

Guideline approaches. The guideline approach to MNT provides individuals with diabetes principles to apply to their current eating habits. Appropriate guidelines are based on an individual’s diabetes management goals. Three education pamphlets available through the ADA that facilitate nutrition education via the guideline approach are: The First Step in Diabetes Meal Planning;⁶ Healthy Food Choices;⁷ and Eating Healthy Foods.⁸

Specific guidelines included in these pamphlets are:
• Eat meals and snacks at regular times every day.
• Use less fat.
• Eat high fiber foods, such as fruits, vegetables, grains, and beans.

These guidelines are teamed with an individual’s current food choices to reach the desired diabetes management goal. For example, a patient eats 1–2 large meals per day and is inconsistent with the timing and caloric distribution of these meals. Providing the guidance to be consistent with meal times and to coordinate with endogenous or exogenous insulin may be the first step to reaching diabetes management goals for this patient.

Meal planning approaches. The meal planning approach is the intervention most typically associated with nutrition management of diabetes. While the diabetes Exchange Lists is the method most often associated with meal planning, a variety of approaches exist (see Table 8).

This form of intervention consists of a variety of meal planning approaches. Three of these meal planning approaches were developed by the ADA and The American Dietetic Association. They are available in written, patient education material through the ADA. The First Step in Diabetes Meal Planning⁶ and Healthy Food Choices⁷ are colorful brochures that open out to be 11-by-18-inch posters. They provide basic diabetes nutrition guidelines, as well as a diabetes meal plan. Both of these brochures use a low literacy level. These are good starting points for individuals for whom a meal planning approach is indicated. The Exchange Lists for Meal Planning⁹ includes six lists of foods, which are grouped into the three major macronutrients—carbohydrate, protein, and fat. The nutrition educator, together with the patient, determine the number of servings from each list appropriate for meals and snacks.

Meal planning approaches that use counting nicely facilitate the modification of a macronutrient. They are an appropriate match when specific nutrient intervention is the goal. Carbohydrate counting is quickly becoming the method of choice for many individuals with IDDM or NIDDM who are interested in following intensive diabetes management. The close relationship of total carbohydrate intake to glycemic control indicates the benefit of carbohydrate counting. Appropriate modification in activity or medication needs to be taken if carbohydrate intake deviates. The ADA and The American Dietetic Association recently published educational pamphlets at three levels of complexity to assist individuals with the meal planning approach.^10-12

Fat counting is beneficial in at least two situations. Limiting total fat intake to 30% or less of total calories with less than 10% as saturated fat is an appropriate therapy for individuals with an elevated lipid profile. Additionally, this method is beneficial in eucaloric or hypocaloric meal plans because of the caloric density of fat.

Protein counting is often indicated for individuals with beginning stages of diabetic nephropathy. The ADA Nutrition Guidelines4 suggest 0.8 gm protein/kg of body weight as a beneficial protein modification for controlling the progression of diabetes kidney disease.

Conclusion
MNT is an essential and cost-effective component of health plans for achieving and maintaining optimal glucose control. The DCCT demonstrated the benefits of using registered dietitians with expertise in diabetes and meal planning.³

If you are interested in referring patients to a diabetes nutrition specialist or registered dietitian with expertise in diabetes management, contact your local dietetic association, state ADA affiliate, the American Diabetes Assocation (1-800-DIABETES) or The American Dietetic Association at 1-800-366-1655. Translating the ADA recommendations for MNT into practical and palatable guidelines for individual use is a combination of art and science in diabetes nutrition management.

¹Ney D, Hollingsworth DR: Nutritional management of pregnancy complicated by diabetes: historical perspectives. Diabetes Care 4:647-55, 1981.

²Franz JM, Monk A, Barry B: Effectiveness of medical nutrition therapy provided by dietitians in the management of non-insulin-dependent diabetes mellitus: A randomized, controlled clinical trial. J Am Diet A 9:1009-17, 1995.

³Delahanty LN, Halford BN: The role of diet behaviors in achieving improved glycemic control in intensively treated patients in the Diabetes Control and Complications Trial. Diabetes Care 16: 1453-58, 1993.

⁴Franz M, Horton E, Bantle J, Beebe C, Brunzell J, Coulston A, Henry R, Hoogwerf B, Stacpoole P: Nutrition principles for the management of diabetes related complications. Diabetes Care 17: 490-518, 1994.

⁵The Expert Panel on Blood Cholesterol Levels in Children and Adolescents: Report of the expert panel on blood cholesterol levels in children and adolescents. Pediatrics (Suppl.) 89:525-84, 1992.

⁶The American Diabetes Association and The American Dietetic Association: The First Step in Diabetes Meal Planning. Alexandria, VA, American Diabetes Association, 1995.

⁷The American Diabetes Association and The American Dietetic Association: Healthy Food Choices. Alexandria, VA, American Diabetes Association, 1986.

⁸The American Diabetes Association and The American Dietetic Association: Eating Healthy Foods. Alexandria, VA, American Diabetes Association, 1988.

⁹The American Diabetes Association and The American Dietetic Association: Exchange Lists for Meal Planning. Alexandria, VA, American Diabetes Association, 1995.

¹⁰Daly A, Barry B, Gillespie S, Kulkarni K, Richardson M: Carbohydrate Counting: Getting Started. Alexandria, VA.:American Diabetes Association; Chicago: The American Dietetic Association, 1995.

¹¹Daly A, Barry B, Gellespie S, Kulkarni K, Richardson M: Carbohydrate Counting: Moving On. Alexandria, VA.: American Diabetes Association; Chicago: The American Dietetic Association, 1995.

¹²Daly A, Barry B, Gillespie S, Kulkarni K, Richardson M: Carbohydrate Counting: Using Carbohydrate/Insulin Ratios. Alexandria, Va.: American Diabetes Association; Chicago: The American Dietetic Association, 1995.

Marie Karlsen, RD, CDE, Dorrine Khakpour, RD, CDE, and Leslie Lobeda Thomson, MS, RD, are diabetes nutrition specialists at the Diabetes Care Center, University of Washington Medical Center, Seattle, Wash.

Table 2. How various nutrients affect blood glucose
Nutrient	% Nutrient Absorbed as Glucose	Time Required for Absorption
Carbohydrate Protein Fat	100% 50-60% 10%	5 min - 3 hours 3-6 hours 8 hours

Table 7. Task approaches
Approach	Benefits	Drawbacks
Food or diabetes management review	Specific, real life	Requires records
Grocery receipt review	Easy, real life	Little focus on meal spacking/medications
Individual goal setting	Specific, real life	Constant updating
Pre-planned menus	Specific, good place to start	Little flexibility, limits decision making for patient.

Table 8. Meal planning approaches
Approach	Benefits	Drawbacks
Food Guide Pyramid¹	Uses for general public spacing	Little focus on meal
Healthy Food Choices, Eating Healthy Foods²	Mixes guidelines with meal plan	Often perceived as diet
Exchange Lists for Meal Planning³	Places emphasis on all nutrient groups	Concept is difficult for many to understand
Counting plans	Good approach for specific nutrient intervention	Requires committed learner
Carbohydrate	Indications: Intensive therapy	Ignores other nutrients
Protein	Indications: Diabetic nephropathy	Ignores other nutrients
Fat	Indications: Weight or lipid concerns	Ignores other nutrients