Center for Human Nutrition

Medical Nutrition Syllabus

Guide to Healthy Diet and Lifestyle

Exercise Guidelines

Managing Obesity

Exercise Prescription

Medicine and Surgery Nutrition Assessment Checklist

Pediatric Nutrition Assessment Checklist

Adolescent Nutrition Assessment Checklist
Syllabus Menu: | Dietary Assessment | Weight Assessment | Dietary Recommendations | Nutritional Deficiencies | Nutrition During Lifecyle | Nutrition in Pathological Conditions | Vegetarianism | [Popular Diets | References |

 
Nutrition in Pathological Conditions

OBESITY

Obesity is defined as excess body fat and is a risk factor for several diseases, most notably cardiovascular disease and cancer. The management of obesity is a difficult task requiring both knowledge and patience on the part of physician and patient. The Shape Up America program, founded by former Surgeon General C. Everett Koop, has formulated a treatment model (see flow diagram on page 21) for obesity which provides a clear and simple guideline for intervention in the overweight adult. An extremely

important underlying principle of successful obesity treatment is that the physician is the "agent of change," taking an active part in the patient’s regime. Most overweight individuals have attempted to achieve a desirable body weight for a substantial portion of their lives, without much long-term success. It is incumbent on the primary care physician to educate and guide patients through this complex and often arduous process.

Some comments regarding the flow diagram:

  1. A BMI of less than 25 is desirable. (Refer back to section on Assessing Your Patient’s Weight to review relative risk of BMI levels.) An initial target may be 2 BMI points below patient’s current level. Even modest weight loss can improve health.
  2. Consider implementing this model when a patient indicates an interest in losing weight, has a comorbid condition exacerbated by excess fat, or requests assistance in maintaining a healthy body weight.
  3. Comorbid conditions include hypertension, cardiovascular disease, dyslipidemia, diabetes, sleep apnea, osteoarthritis, and gallstones.
  4. Pregnant patients should not be encouraged to "diet."
  5. Other risk factors include waist-to-hip ratio >1.0 in males and > 0.8 in females, history of obesity in the individual or his family, hyperinsulinemia, cancer (especially breast, colon, endometrial), physical inactivity.
  6. Weight reduction strategies start with dietary and lifestyle changes combined with increased physical activity. The goal is to create an energy deficit as well as develop permanent healthy lifestyle habits.
  7. If insufficient progress toward the target BMI, consult an obesity specialist regarding possible pharmacotherapy or surgical treatment.
  8. Institute a program for long-term maintenance and prevention of weight gain.
  9. Consider the possibility that an obese patient may have an eating disorder.

CANCER

Overview

Both population and experimental studies have strongly implicated an important role for diet and specific nutrients in the development of certain cancers. In addition, several dietary components have also been suggested as having a protective effect in reducing the risk of developing certain cancers. Conservative estimates attribute at least 30% of cancer incidence to dietary patterns. Many health organizations including the American Cancer Society and the national Cancer Institute have provided dietary guidelines for reducing the risk of several cancers. Dietary habits have been estimated by numerous investigators to be correlated with as many as 60% of cancers in women and 40% of cancers in men. The NCI Guidelines are as follows:

  1. Consume at least five servings of fruits and vegetables per day. In countless population studies, a high intake of fruits and vegetables has been associated with reduced cancer risk. Lung, colon, breast, ovarian, prostate and upper GI are among the cancers that have been studied. The protective effect of fruits and vegetables is attributed to the potentially anticarcinogenic agents found in these foods. The mechanisms of action of these agents are many. They include antioxidant effects, induction of detoxification enzymes, inhibition of formation of carcinogens such as nitrosamines, binding of carcinogens in the digestive tract and alteration of hormone metabolism, to name a few. Some of the compounds most intensely studied and thought to be chemoprotective are carotenoids, vitamins C, D and E, folic acid, selenium, fiber, flavonoids (soybeans and green tea), indoles (broccoli, cabbage), allyl compounds (garlic, onions), and limolene (citrus oils, spices). Unfortunately, it is estimated that only between 10 and 20% of the US population consumes the recommended five or more daily servings of fruits and vegetables. Dietary habit adjustments provide the ideal opportunity for intervention to potentially reduce an individual’s risk for selected cancers.
  2. Decrease total fat in the diet, including both saturated and polyunsaturated fats. The link between dietary fat intake and certain forms of cancer has been somewhat controversial, especially with respect to breast cancer. However, there is much convincing epidemiological, clinical and laboratory evidence that such a link exists, particularly for cancers of the breast, prostate and colon. International comparisons of dietary fat intake indicate a strong correlation between increased incidence of certain cancers and increased fat intake. Incidence of breast cancer in Asian women has been shown to approach that of American women when they migrate to this country and adopt a Western diet and lifestyle. The mechanism of action for the effects of fat is proposed to be one of tumor promotion and possibly of tumor initiation. Polyunsaturated fats are highly implicated in the oxidation of various cell constituents.
  3. Increase dietary fiber intake. There is a very strong relationship between high fiber intake and decreased rates of colon cancer. Insoluble fiber (wheat bran) is largely indigestible, providing bulk to the stool and decreased transit time. It also is thought to bind various toxins in the stool such as bile acids, as well as dilute toxins present in the stool, thereby reducing the likelihood of these potentially mutagenic agents coming in contact with the bowel mucosa. Soluble fiber (oat bran) is partially digestible and is more associated with the binding of cholesterol and lower risk of cardiovascular disease.
  4. Avoid excess caloric intake and maintain a desirable body weight through exercise and a healthy diet. Obesity, defined as excess body fat, has been strongly associated with cancers of the breast, ovary, endometrium and colon. The proposed mechanism for the effect of excess body fat on the reproductive organs is enhancement of estrogen effect on the target organs. Substantial evidence exists for the promotion of reproductive tumors by estrogens. Adipose tissue contains an enzyme (aromatase) which is capable of converting adrenal androgens to estrone and subsequently to estradiol. This source of non-ovarian estrogen is a probable explanation for the association between obesity and increased breast cancer risk in postmenopausal women. Other growth factors such as insulin may also promote carcinogenesis.
  5. Avoid excessive alcohol consumption. Alcohol is a suspected promoter of tumor growth. Excess consumption is highly correlated with cancers of the larynx, pharynx, oral cavity and esophagus. A nitrosamine found in beer and whiskey has been implicated in cancer of the rectum.
  6. Avoid smoked, pickled or poorly preserved foods. These foods contain various carcinogens including nitrates and nitrites, which have been implicated in stomach cancer, particularly outside the US. Spoiled or moldy foods may contain aflatoxin, which has been associated with liver cancer.

Cardiovascular Disease

· Hyperlipidemia

Risk Factors for Coronary Heart Disease:

  • Age (men > 45, women > 55 or those who have undergone premature menopause and are not on estrogen therapy
  • Family history of premature cardiovascular disease (father > 55, mother > 65)
  • Current cigarette smoking
  • Hypertension (>140/90 mm Hg, or individuals taking anti-hypertensive medications)
  • Diabetes Mellitus
  • Decreased HDL level (<35 mg/dl)

Guidelines for establishing diet therapy to Reduce Cholesterol (1993 NCEP national guidelines recommending < 30% fat):

  • If the patient is without heart disease and has one or no risk factors, initiate dietary recommendations if the LDL level is greater than 160mg/dl.
  • If the patient is without heart disease and has two or more risk factors, initiate dietary recommendations if the LDL level is greater than 130mg/dl.
  • If the patient has heart disease, initiate dietary recommendations if the LDL level is greater than 100mg/dl.

Goals of nutritional therapy for cardiovascular disease:

  • Maintain a healthy body weight with a BMI of <25.
  • Do not exceed 20% of total calories from fat.
  • At least 25 grams per day of fiber, both soluble and insoluble.
  • Complex carbohydrates as in fruits, vegetables and grains, should provide the major portion of energy.
  • Dietary cholesterol <300 mg per day for individuals with normal lipid profile.
  • Restrict visible fat consumption such as cheese, red meat, butter, margarine, mayonnaise, whole milk, ice cream, peanut butter and high fat salad dressings.
  • Increase intake of soy protein, especially those that are isoflavone-rich such as soy protein powder beverages.
  • Preferred form of fat is monounsaturated fat such as olive or canola oil.

Ask patient how many times per week they eat the following foods and what the usual portion size is:

  • Red meat - A good rule of thumb is if your patient is consuming red meat more than 4 times a week, most likely they are not following a low fat diet. A suggested serving size of very lean meat is no more than 3 oz – the size of a deck of cards – and consumption should be kept to a minimum. NCEP recommends limiting protein intake to 10 to 20% of total calories.
  • Poultry - White meat turkey is leaner than white meat chicken. To lower fat content ask patients to remove the skin before eating.
  • Fish and Shellfish - Even lower in fat than poultry. Also contains a rich source for omega-3 fatty acids. Encourage patients to grill it rather than frying it.
  • Dairy products - Cheese and whole milk have a significant amount of saturated fat. Also suggest non-fat yogurt instead of regular yogurt. Patients should avoid high-fat nondairy creamers, whipped toppings and half-and-half.
  • Sweets and Desserts - Most baked commercial products are made with saturated fats like butter and eggs. Fresh fruit, angel food cake, fat-free frozen yogurt, and sherbet are good alternatives. Watch out for fat-free desserts that substitute a large amount of simple sugars for fat. They may be very high in calories.
  • Eating out - There are many hidden sources of fat when dining out. Instead of casserole dishes, suggest that your patient select grilled, poached, baked, or broiled entrees. Also when eating at fast-food restaurants, good low-fat foods include a grilled chicken breast on a bun without sauce and a baked potato.

· Hypertension

Goals of nutritional therapy for patients with hypertension.

  • Promote weight reduction in the overweight and obese: Primary goal for the overweight hypertensive patient. Weight loss can improve lipid levels and lower blood pressure.
  • Reduce sodium intake: Reduce sodium intake to 2 to 3 grams per day. Limit consumption of table salt, and salted, canned, and highly processed foods.
  • Reduce alcohol consumption: Limit to 2 drinks per day for men, one for women.
  • Encourage healthy eating habits and a balanced intake.
  • Encourage increased physical activity level.

Pulmonary Disease

· Chronic Obstructive Pulmonary Disease (COPD)

Patients experience increased weight loss due to:

  • Calories burned due to increased work of breathing.
  • Frequent, recurrent respiratory infections.
  • Depression from the illness.
  • Side affects of medications like nausea, vomiting, diarrhea which can limit dietary intake.
  • Symptoms of the disease which may make eating difficult or undesirable.

Nutritional therapy for COPD:

  • Supply adequate calories, protein, vitamins, and minerals.
  • Add high-calorie, high-protein, liquid nutritional supplements.
  • Recommend foods that are easily prepared like TV dinners.
  • Encourage patients to rest before mealtime.
  • Prescribe a daily multivitamin and mineral supplement.
  • Recommend timing meals with the time patient’s energy levels are highest.
  • Recommend small, frequent meals which are nutrient-dense like peanut butter and jelly sandwiches or yogurt.

· Obstructive Sleep Apnea Syndrome (OSAS)

Associated with weight gain and obesity:

  • Since OSAS causes fatigue during the day, patients may be less motivated to exercise. (Obesity is also a risk factor for OSAS.)
  • OSAS patients fall asleep after meals often, thereby further decreasing energy expenditure.
  • Patients may be subject to depression due to their debilitating condition, and therefore may binge.

Acquire the following information from OSAS patients during medical history:

  • Weight history and previous dieting experience.
  • Sleep patterns.
  • Frequency of meals and snacks especially after dinner.
  • Binge eating during the day or night.
  • Alcohol intake.

Nutritional therapy for OSAS:

  • Weight reduction, since it a risk factor for OSAS.
  • Increasing activity.

Endocrine Disease

· Insulin-Dependent Diabetes Mellitus (Type I)

Ways to achieve the nutritional goals of Diabetes I:

  • Timing of meals with insulin doses -Meals should be eaten during the peak action period of the particular insulin type administered. Since insulin doses are taken at the same time every day, meals should also be taken at regular times and intervals.
  • Consistency of diet -Once an ideal insulin dose is established, the calorie and carbohydrate content of meals should be the same from day to day to maintain a constant blood glucose.
  • Monitoring of blood glucose levels - It is important that the diabetic patient regularly monitor blood glucose levels with self-monitoring systems and periodic glycosylated hemoglobin counts or fructoamine levels.
  • Regular exercise - Is important because it reduces blood glucose levels by decreasing hepatic glucose output and increases peripheral utilization of glucose. A good rule of thumb is that for every hour of exercise performed, 10-15 grams of carbohydrates (orange/slice of bread) should be consumed.

· Non-Insulin Dependent Diabetes Mellitus (Type II)

Ways to achieve the nutritional goals of Diabetes II:

  • Weight loss - Studies have shown that a moderate weight loss accounted for the reduction of hyperglycemia, hyperlipidemia and hypertension in those with Type II diabetes. About 80% of the patients with NIDDM are overweight.
  • Spacing of meals - There is controversy over the optimal spacing of meals. Some recommend dividing total daily intake into smaller, spread-out meals and snacks throughout the day, while others believe 3 meals spaced a few hours apart is ideal.
  • Regular exercise - Regular aerobic exercise has been shown to increase insulin sensitivity, increase glucose utilization, and decrease weight. Exercise also lowers blood lipids. Those taking oral hypoglycemic agents should be concerned with post-exercise hypoglycemia.

Nutritional Therapy for Diabetes

  • Calories - If the patient is overweight, weight loss is best attempted by a moderate decrease in calories and an increase in caloric expenditure. Moderate caloric restriction (250–500 calories less than average daily intake) is recommended. Other than that, calorie intake should follow healthy dietary guidelines.
  • Protein -There is limited scientific data upon which to establish firm nutritional recommendations for protein intake for individuals with diabetes. At the present time, there is insufficient evidence to support protein intakes either higher or lower than average protein intake for the general population (~10–20% of the daily caloric intake from protein). Dietary protein should be derived from both animal and vegetable sources. With the onset of overt nephropathy, lower intakes of protein should be considered. A protein intake similar to the adult RDA (0.8 g/kg/day), ~10% of daily calories, is sufficiently restrictive and is recommended for individuals with evidence of nephropathy.
  • Total Fat - Less than 10% of calories should be from saturated fats and up to 10% calories from polyunsaturated fats, leaving 60–70% of the total calories from monounsaturated fats and carbohydrates. The distribution of calories from fat and carbohydrate can vary and be individualized based on the nutrition assessment and treatment goals. If obesity and weight loss are the primary issues, a reduction in dietary fat intake is an efficient way to reduce caloric intake and weight, particularly when combined with exercise. If elevated LDL cholesterol is the primary problem, the National Cholesterol Education Program Step II diet guidelines, in which <7% of total calories are from saturated fat, <30% of the calories are from total fat, and dietary cholesterol is <200 mg/day (11.1 mmol/l), should be implemented.
  • Saturated fat and cholesterol - A reduction in saturated fat and cholesterol consumption is an important goal to reduce the risk of cardiovascular disease (CVD). Diabetes is a strong independent risk factor for CVD, over and above the adverse effects of elevated serum cholesterol. Therefore, <10% of the daily calories should be from saturated fats, and dietary cholesterol should be limited to 300 mg or less daily.
  • Carbohydrates and sweeteners - The percentage of calories from carbohydrate will also vary, and is individualized based on the patient's eating habits and glucose and lipid goals. In general, foods with a lower glycemic index (converted to sugar more slowly) are favored over those that are rapidly converted to glucose.
  • Sucrose - Studies have shown sucrose does not impair blood glucose control in individuals with type I or type II diabetes. Sucrose and sucrose-containing foods must be substituted for other carbohydrates and not simply added to the meal plan.
  • Fructose - Although people with dyslipidemia should avoid consuming large amounts of fructose, there is no reason to recommend that people avoid consumption of fruits and vegetables, in which fructose occurs naturally, or moderate consumption of fructose-sweetened foods.
  • Other nutritive sweeteners - Nutritive sweeteners other than sucrose and fructose include corn sweeteners such as corn syrup, fruit juice or fruit juice concentrate, honey, molasses, dextrose, and maltose. There is no evidence that these sweeteners have any significant advantage or disadvantage over sucrose in terms of improvement in caloric content or glycemic response. Sorbitol, mannitol and xylitol are common sugar alcohols (polyols) that produce a lower glycemic response than sucrose and other carbohydrates.
  • Non-nutritive sweeteners - Saccharin, aspartame, and acesulfame K are approved for use by the Food and Drug Administration (FDA) in the United States. Non-nutritive sweeteners approved by the FDA are safe to consume by all people with diabetes.
  • Fiber - Dietary fiber may be beneficial in treating or preventing several gastrointestinal disorders, including colon cancer, and large amounts of soluble fiber have a beneficial effect on serum lipids. Although selected soluble fibers are capable of delaying glucose absorption from the small intestine, the effect of dietary fiber on glycemic control is probably insignificant. Therefore, fiber intake recommendations for people with diabetes are the same as for the general population (20–35 g dietary fiber from a wide variety of food sources).
  • Sodium - People differ greatly in their sensitivity to sodium and its effect on blood pressure. Because it is impractical to assess individual sodium sensitivity, intake recommendations for people with diabetes are the same as for the general population.
  • Alcohol - The same precautions regarding the use of alcohol that apply to the general public (no more than two drinks per day for men and no more than one drink per day for women) also apply to people with diabetes. Special considerations for further modification of alcohol intake include the following: alcohol abuse, pregnancy, pancreatitis, dyslipidemia, or neuropathy. Alcohol may increase the risk for hypoglycemia in people treated with insulin or sulfonylureas, and it should only be ingested with a meal.
  • Vitamins and Minerals - When dietary intake is adequate, there is generally no need for additional vitamin and mineral supplementation for the majority of people with diabetes. The only known circumstance in which chromium replacement has any beneficial effect on glycemic control is for people who are chromium deficient as a result of long-term chromium-deficient parenteral nutrition. However, it appears that most people with diabetes are not chromium deficient and, therefore, chromium supplementation has no known benefit.

Renal Disease

· Acute Renal Disease

Goals of nutritional therapy for ARF patients:

  • Minimize uremia and maintain the body’s regular chemical composition.
  • Preserve the body’s protein stores.
  • Maintain fluid, electrolyte, and acid-base homeostasis.

Nutritional therapy for ARP patients:

  • Protein - Restrict protein intake to 0.6g/kg/day in non-dialyzed, non-hypercatabolic patient with a GFR of less than 10ml/min.
  • Calories - Usual recommendation is 35 kcal/kg/day but may vary.
  • Vitamins/Minerals - Electrolytes must be closely monitored. Potassium and phosphate levels may be elevated. There may also be salt and water imbalances.
  • Fluids - Daily fluid intake should equal urine output, plus approximately 500ml to replace insensible losses.

· Chronic Renal Failure

Goals of nutritional therapy for patients with chronic renal failure prior to dialysis or renal transplantation:

  • Prevent symptoms of uremia while restoring biochemical balance.
  • Retard progression of the disease.
  • Provide adequate calories to maintain or achieve ideal body weight.

Nutritional therapy for chronic renal failure:

  • Protein -Necessary to control the level of protein intake while continuing to maintain a positive nitrogen balance. Protein should be restricted to 0.6g/kg/day, with sufficient essential amino acids.
  • Calories - Calorie intake should be about 35 kcal/kg to maintain body weight. There should be adequate calories from complex and simple carbohydrates in the diet. Foods such as fruit drinks, regular carbonated drinks, and honey are good for achieving this goal.
  • Fat - Additional fat may be needed to provide the patient adequate calories. Mono- and polyunsaturated fats are good sources. It is necessary to monitor lipid and cholesterol levels.
  • Sodium - Levels may drop as renal failure progresses. Sodium may have to be limited, since the kidneys may lose their ability to excrete it. Two to three grams per day may be adequate, but 1 gram per day may be needed if the renal failure is severe.
  • Potassium - If renal failure is severe enough to produce a serum potassium level of greater than 5.0 mEq/day, then a potassium restriction of 2 to 3 grams/day should be initiated. Keep in mind that if a patient is on an ACE inhibitor, their serum potassium levels will rise.
  • Calcium and Phosphate - Restricting dietary phosphate has been shown to prevent secondary hyperparathyroidism, which is common in chronic renal failure patients. When the GFR level falls below 25ml/minute, it is necessary to supplement calcium and restrict phosphate to 8-12 mg/kg/day.
  • Water Balance - As long as the urine output is equal to fluid intake, a patient is in fluid balance. Therefore, fluid intake should be based on the patient’s ability to eliminate fluid.
  • Vitamins - Due to the protein and mineral restrictions of chronic renal failure, many times there are deficiencies in vitamins and minerals. Supplementing folic acid, pyridoxine, B-complex vitamins and ascorbic acid may be necessary. Also, since the kidney loses its ability to make the active form of Vitamin D, an activated Vitamin D supplement may be necessary. Vitamin A should not be supplemented because it may accumulate with renal failure. Patients receiving erythropoietin therapy may require iron supplementation to prevent anemia.

· Nephrolithiasis (Kidney Stones)

  • Nutritional therapy for nephrolithiasis:
    • Fluids - A high fluid intake is the most essential part of the diet therapy for kidney stones. A daily fluid intake of 2.5-3 liters is recommended to dilute the concentration of substances that form stones. A recent study showed that any fluid other than grapefruit juice reduces the risk of stones.
    • Calcium - Hypercalciuria is the main metabolic abnormality associated with calcium stones. Contrary to common belief, a low calcium diet may increase the absorption of oxalate, promoting the formation of calcium oxalate stones. Therefore, a calcium intake of 600-800 mg/day is recommended to prevent hyperoxaluria. For patients with inadequate dietary intake of calcium, increasing dairy products is a good way of achieving this goal.
    • Oxalate - Excretion level is the most important factor in developing calcium oxalate stones. Gastrointestinal disorders are the most common cause of enteric hyperoxaluria. Since small increases in urinary oxalate concentration may greatly increase stone formation, reducing urinary oxalate by reducing dietary oxalate may benefit kidney stone patients. However, it is important to reduce dietary oxalate without reducing dietary calcium.
    • Protein - Since high intake of animal protein increases calcium excretion, it is advisable to limit foods such as meat, fish, poultry and eggs.
    • Sodium - A high sodium diet can increase calcium excretion by increasing extracellular fluid volume, thus increasing GFR. Increasing GFR will decrease the renal calcium reabsorption. It is therefore advisable to reduce foods high in sodium.
    • Carbohydrate-simple sugars promote the excretion of calcium and oxalate and promote calciuria. Also in some individuals, insulin can promote calcuria as well. In these patients it is advisable to cut down on refined carbohydrates.

Gastrointestinal Disease

· Peptic Ulcer Disease

Nutritional Therapy for Peptic Ulcer Disease:

  • Eat three meals a day; avoid skipping meals; and limit intake of spicy, fatty, or otherwise bothersome foods.
  • Limit caffeine intake by reducing consumption of coffee, tea, cola, chocolate, and other foods and beverages that contain caffeine.
  • Limit alcohol intake and avoid drinking on an empty stomach.
  • Avoid cigarette smoking, which may increase gastric acid secretion and delay the healing process.
  • Avoid bedtime snacks to prevent acid secretion, if symptoms often occur in the middle of the night.

· Gastroesophageal Reflux Disease (GERD)

Goals of the nutritional therapy for patients with GERD:

  • Avoid decreases in lower esophageal sphincter (LES) pressure.
  • Decrease the frequency and volume of reflux.
  • Reduce irritation of sensitive or inflamed esophageal tissue.
  • Improve esophageal clearing time.

Nutritional therapy for patients with GERD:

  • Maintain LES pressure
    • Limiting dietary fat intake: high-fat meals decrease LES pressure.
    • Losing weight: obesity increases abdominal pressure.
    • Limiting alcohol, chocolate, and coffee: they decrease LES pressure.
  • Decrease reflux frequency and volume
    • Eating small meals and eating more frequently, if necessary.
    • Losing weight if overweight.
    • Drinking most fluids between meals, rather than with them.
    • Consuming adequate fiber to avoid constipation, because straining increases intra-abdominal pressure.
  • Decrease esophageal irritation
    • Limit intake of citrus fruits, tomato products, spicy foods, and carbonated beverages.
  • Improve esophageal clearing time
    • Do not recline after eating. Sit upright or take a walk.
    • Avoid eating within 2 to 3 hours before bedtime.
    • Elevate the head of the bed.

· Malnutrition

Medical risk factors

  • grossly underweight: weight for height below 80% of the standard
  • grossly overweight: weight for height above 120% of the standard
  • recent loss of 10% of more of body weight, unintentionally
  • gastrointestinal tract surgery
  • excessive nutrient losses (as from diarrhea, dialysis, vomiting)
  • increased metabolic needs (pregnancy, lactation, fever, injury)
  • alcoholic or chronic drug use (antibiotics, antidepressants, diuretics)
  • medical conditions which interfere with nutrient intake, absorption, metabolism, or utilization
  • poor dentition, particularly in the elderly
  • mouth sores due to herpes or HIV
  • Dietary risk factors
    • loss of appetite
    • inadequate food or nutrient intake
    • lack of variety of foods
    • fad, weight-loss diets
    • inadequate fiber
    • excessive fat, sodium, sugar
    • excess alcohol
    • eats too few fruits, vegetables
  • Social risk factors
    • chronic ill health
    • poverty; inadequate money to buy food
    • low socioeconomic status, which often accompanies bad health
    • immobility or inability to purchase, store, or cook food
    • social isolation; eats alone most of the time
    • substance abuser
    • conditions which limit individual’s ability to eat

· Malabsorption

Carbohydrate Malabsorption

  • Causes osmotic diarrhea.
  • Lactose intolerance is most common form.
  • 15% of Caucasians and 90% of African and Asian Americans are lactase deficient.
  • Clinical symptoms include abdominal cramps, bloating and diarrhea.

Nutritional Therapy for Carbohydrate Malabsorption

  • Pretreating milk with lactase derived from bacteria.
  • Ingesting only lactose-treated dairy products, such as Lactaid or Dairy Ease.
  • Reducing or avoiding lactose intake (dairy products).

 

Fat Malabsorption

  • Includes the inability to digest triglycerides, diglycerides, monoglycerides, fatty acids, phospholipids, cholesterol, cholesterol esters, and bile acids.
  • Since lipids are a major source of calories, numerous problems may occur with fat malabsorption.

Clinical symptoms of fat malabsorption

  • Failure to thrive, growth retardation, fatigue, especially in infants, children, and adolescents.
  • Weight loss, muscle wasting.
  • Tetany, osteomalacia, bone pain, compression fracture of vertebra body due to hypocalcemia secondary to calcium malabsorption.
  • Infertility, dysmenorrhea, amenorrhea.
  • Renal oxalate stones may form due to bile salt malabsorption (ileal Crohn’s disease).

Fat-soluble vitamin deficiencies and clinical signs

  • Vitamin A - Night blindness, hyperkeratosis, skin changes
  • Vitamin D - Hypocalcemia, osteomalacia, rickets, hypophosphatemia
  • Vitamin E - Neuropathy, hemolytic anemia
  • Vitamin K - Prolongation of prothrombin time, easy bruising
  • Alcohol provides 7 kcal/g, but lacks in vitamins and minerals. Also, since alcohol disrupts the
  • Wernicke’s encephalopathy and macrocytic anemia, respectively. Patients who do not respond to oral supplements may require subcutaneous injections of vitamins. If a diuretic is being taken, serum potassium, zinc and magnesium levels should be closely monitored.

· Irritable Bowel Syndrome (IBS)

  • Patients with IBS have disordered motility, with alternating bouts of diarrhea and constipation. Pain and bloating are frequent complaints, and episodes are often precipitated by emotional distress or increased life stresses.

Nutritional Therapy for Irritable Bowel Syndrome

  • Bland diet is often recommended during severe episodes, avoiding coffee and other caffeine-containing substances, alcohol, hot spices and fried or fatty foods.
  • Fiber - A high-fiber diet is recommended for patients with IBS to help normalize intestinal motility. The fiber increases bulk to aid in constipation, and absorbs water to slow diarrhea.
  • Lactose - Some patients with IBS may be lactose intolerant. Symptoms of lactose intolerance include bloating, cramps, and diarrhea. Patients may choose to consume lactose-treated milk or lactose pills, instead of completely eliminating dietary lactose.