Center for Human Nutrition
Medical Nutrition Syllabus
Guide to Healthy Diet and Lifestyle
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 |
All dietary recommendations should be considered within the framework of a nutritionally balanced diet. The goal for each and every patient is healthy eating primarily achieved by consumption of a combination of low fat, high fiber foods. The UCLA Center for Human Nutrition has constructed a variation of the USDA Food Pyramid, the California Cuisine Pyramid, which illustrates our plant-based diet for healthy eating. (See pyramids on pages 9 and 10.) Target fat consumption is 20% of total calories. Fats, oils and spices should all be used only to enhance taste. You will also notice that the base of this pyramid is fruits and vegetables, rather than carbohydrates and grains as in the USDA version. Fruits and vegetables should constitute the cornerstone of the diet, with a total of six to eleven servings per day. Fewer than 20% of Americans consume at least five servings of fruits and vegetables daily. One of the goals of this new pyramid is to educate patients that a diet based fundamentally on fruits, vegetables and grains will enable them to best achieve the goal of a low fat, moderate calorie meal plan. It also allows for maximum concentration of chemoprotective micronutrients, such as phytochemicals and antioxidants, while providing optimum fiber and protein intake.
Daily Meal Plan
USDA Food Pyramid
- The American Heart Association has recommended that fat intake be less than 30% of the total calories consumed per day. However several researchers in the field of clinical nutrition have shown that those who consume fat calories in a range of 20-25% of total calories have lower rates of obesity, cardiovascular disease and several types of cancer. The average American consumes 37% of total calories as fat.
- Dietary fats are a combination of saturated and unsaturated fatty acids. Saturated fats, with a few exceptions, are solid at room temperature and come from animal sources. The recommended saturated fat intake is 7-10% of total calories per day. Saturated fats have been shown to raise LDL levels more than any other dietary food source.
- Polyunsaturated fats are fatty acids with two or more double bonds, are primarily liquid at room temperature and come from plants and fish. Two major categories are the omega-6 and omega-3 fatty acids. One omega-6 fatty acid, linoleic acid, is an essential fatty acid and one of the precursors of prostaglandin synthesis. Omega-6 fatty acids, found in vegetable oils such as corn, sunflower and safflower, lower LDL levels and may possibly lower HDL levels, especially if total intake is greater than 10%. Omega-3 fatty acids, found in cold-water fish oils and flaxseed oils, have been shown to decrease triglyceride and LDL levels as well as increase clotting times.
- Monounsaturated fats are fatty acids with one double bond. They are the "preferred" forms of fat because they do not appear to increase LDL levels. Also, those who consume a typical Mediterranean diet relatively rich in monounsaturated fats such as olive oil have a lower incidence of cardiovascular disease and breast cancer. Other sources include canola oil, avocados and most nuts. Remember: these fats are still 100% fat calories and must be consumed in quantities consistent with the recommendation of 20-25% of total calories from fat.
- Trans fatty acids are formed by the addition of hydrogen atoms to polyunsaturated fat. The process is utilized frequently by food manufacturers to improve shelf life. They have been shown to increase LDL levels.
Complex (Starch and fiber)
- Plant foods rich in complex carbohydrates and fiber reduce the risk of chronic disease in several ways. Soluble fiber from plant foods independently lowers blood lipid levels and blood sugar levels and thus lowers risk of cardiovascular disease and diabetes. Insoluble fiber, such as wheat bran, aids in bulk and elimination, and may help prevent colon cancer. Numerous vitamins and minerals found in plant foods contribute to the maintenance of good health, as well as possibly providing protection against particular forms of cancer. A diet high in plant foods is also likely to be low to moderate in fat levels.
- Soluble fiber includes pectins found in fruits, gums found in oats and legumes, and psyllium found in seed husks (Metamucil).
- Increased intake of legumes, high fiber cereals, fruits and vegetables is the best way to increase dietary fiber.
- Optimal level of fiber is >25 grams per day.
- Sugars and the many foods containing them are often high in calories and low in nutritional value. In addition, sucrose consumption is clearly a major factor in the development of tooth decay.
- Optimum protein intake is currently being researched heavily. The Recommended Dietary Allowance (RDA) for a healthy adult is 0.8-1.0 grams per kilogram of ideal body weight per day. Children require 1-2 grams per kilogram per day. Pregnant and lactating females and individuals under conditions of hypermetabolism such as infection or trauma will require increased intake.
- The body is dynamic and its proteins are continuously being degraded and resynthesized. The primary function of dietary protein is furnishing amino acids for the growth and maintenance of body tissue.
- About 25% of the daily total protein requirement should be met with branched chain amino acids – valine, leucine and isoleucine – since they are major components of muscle and in times of stress are metabolized by muscle.
- While protein deficiency is a major health concern in many underdeveloped nations, the major concern in the United States is excess consumption. U.S. surveys indicate daily consumption is on average double the RDA with 69% coming from animal origin (48% from meat, 17% from dairy, and 4% from eggs). High intake of animal protein can increase urinary calcium loss and can contribute to increased levels of homocysteine, a risk factor in coronary artery disease. Homocysteine levels can be controlled with higher levels of folic acid, a vitamin found in vegetables and legumes.
- For those attempting to reduce their fat intake, including red meat, while simultaneously increasing their lean body mass, it is important to recommend a reasonable protein intake – approximately 0.5 gram of protein per pound of body weight. A given individual’s optimum protein intake depends on weight, exercise and age. While protein contributes to the overall energy available to the body, very little is actually metabolized except in the fasting state or during exercise. Therefore, excess protein becomes excess calories, which becomes fat.
RECOMMENDED DAILY ALLOWANCES (RDAs), FOOD SOURCES, DEFICIENCY/EXCESS
- USRDA = U.S. Recommended Daily Allowance. Devised by the FDA for nutritional labeling. They are listed on processed foods indicating the percentage of each of 19 essential nutrients a product contains per serving or dose. Not differentiated by age or sex. Based on RDAs.
- RDA = Recommended Dietary Allowance. Set by the Food and Nutrition Board of the National Academy of Sciences. Represents the intake levels of essential nutrients considered to be adequate to meet the nutritional needs of most healthy persons. RDAs do not cover increased nutritional requirements due to disease or medication use, and they should not be confused with nutritional requirements, which may vary from person to person. A varied diet rich in fruits, vegetables and whole grains is the ideal way to assure proper intake of micronutients.
- RDA: 1000 RE for males, 800 RE for females, 700 RE for children, 375 RE for infants; 5000 IU is typical recommended daily intake.
- Food sources: liver, fish liver oils, dairy products, eggs, and butter. Beta-carotene form can be found in carrots and dark green leafy vegetables like spinach, sprouts, and broccoli.
- Deficiency: night blindness, drying of skin, keratomalacia, compromised immune system.
- Excess: nausea, vomiting, abdominal discomfort, joint pain, itching, hair loss, dry lips. May cause yellowing of the skin and sclera, which disappear when intake is decreased.
- While the preformed vitamin is toxic in high doses, the precursor beta-carotene is not.
- Beta-carotene is part of several antioxidant formulas, although its role in cancer and cardiovascular disease prevention is a matter of some controversy.
- RDA: 200 IU for males, females, and children; 400 IU for infants; recommended daily intake is 400 IU, the amount found in most multivitamin supplements; need to take into account the total intake from food and supplements.
- Food sources: fish liver oils, fatty fish like tuna and salmon, fortified margarine, eggs, liver.
- Deficiency: rickets, osteomalacia, and renal osteodystrophy.
- Excess: diarrhea, dermatitis, hypercalcemia, headache, nausea, loss of appetite, impaired renal function and retarded growth.
- Facilitates calcium transport across intestinal mucosa.
- Most people who are not housebound get enough from exposure to sunlight, though many elderly patients are deficient.
- Some evidence exists that it may reduce the risk of colorectal cancer.
- RDA: 10 mg for males, 8 mg for females, 7 mg for children, 4 mg for infants; recommended antioxidant levels of 200-400 IUs per day are hard to achieve by diet alone and are best found in food sources high in fat (oils, eggs, butter), so supplements are usually suggested. (The average multivitamin only contains 30 IUs of E.) Vitamin E supplementation at the suggested levels of 200-400 IUs per day has been thoroughly examined in several studies and no deleterious effects have been found.
- Food sources: vegetable oils, eggs, butter, wholemeal cereals, and broccoli.
- Deficiency: red cell hemolysis in malnourished infants, mild hemolytic anemia.
- Excess: may exacerbate coagulation defects in vitamin-K deficient individuals (those with malabsorption or taking anticoagulants).
- Powerful antioxidant.
- Found to lower heart disease in several studies.
- RDA: 80 mg for males, 65 mg for females, 30 mg for children, 10 mg for infants.
- Food sources: broccoli, cabbage, lettuce, liver, dark-green leafy vegetables, produced by intestinal bacteria.
- Deficiency: increased clotting time, hemorrhage, especially in newborn infants and those with biliary tract disease.
- RDA: 60 mg for males and females, 45 mg for children, 35 mg for infants.
- Food sources: citrus fruit, strawberries, cantaloupe, tomatoes, broccoli, raw green vegetables, potatoes, cauliflower, cabbage.
- Deficiency: scurvy, poor bone and teeth development, poor wound healing.
- Excess: regular consumption of > 2g/day may cause nausea, vomiting, stomach cramps, diarrhea; large doses may interfere with urine tests for glucose.
- Powerful antioxidant; restores vitamin E to antioxidant form.
- Water-soluble so high doses (>1 gram) are simply excreted in urine and are unnecessary.
- Found to lower cardiovascular risk in several studies.
- May enhance the absorption of nonheme iron in the diet.
- RDA: 1.5 mg for males, 1.1 mg for females, 1.0 mg for children, 0.4 mg for infants.
- Food sources: whole wheat, wheat germ, yeast, pork, nuts, fortified breakfast cereals, meats, milk eggs.
- Deficiency: beriberi, Wernicke-Korsakoff syndrome.
- Excess: oral doses of 300 mg/day are nontoxic in humans, but parenteral doses > 400 mg/day may cause anorexia, lethargy, mild ataxia and reduced intestinal tract muscle tone.
- Alcohol abuse and folate deficiency result in the malabsorption of thiamin. Caffeic acid and tannic acid found in coffee and tea are thiamin antagonists.
- RDA: 1.7 mg for males, 1.3 mg for females, 1.2 mg for children, 0.5 for infants.
- Food sources: liver, kidney, milk, yogurt, cheese, eggs, wheat germ, mushrooms, fortified cereals, poultry, fish, dark-green leafy vegetables.
- Deficiency: cheilosis, burning and itching of eyes.
- RDA: 19 mg for males, 15 mg for females, 13 mg for children, 6 mg for infants.
- Food sources: liver, kidney, meat, poultry, fish, peanuts, bran, whole meal wheat, coffee, dark-green leafy vegetables.
- Deficiency: pellagra.
- Excess: the nicotinic acid form (often used to lower cholesterol) in high doses can lead to cutaneous flushing, abnormalities in hepatic function, hyperglycemia, elevated plasma uric acid and vasodilation.
Vitamin B6 (pyridoxine)
- RDA: 2 mg for males, 1.6 for females, 1.4 mg for children, 0.6 mg for infants.
- Food sources: liver, whole grain cereals, meat, fish, peanuts, bananas, walnuts, avocados, potatoes, beans, dark-green leafy vegetables.
- Deficiency: cheilosis, upset stomach, weak gait, irritability, neuropathy, convulsions, anemia.
- Excess: Doses greater than 500-600 mg/day can produce tingling in hand and feet, lack of muscle coordination, stumbling gait and degeneration of nervous tissue.
- Found to lower homocysteine levels in patients with cardiovascular disease.
Vitamin B12 (cyanocobalamin)
- RDA: 2.0 ug for males and females, 1.4 ug for children, 0.5 ug for infants.
- Food sources: liver, kidney, sardines, oysters, meats, fish, eggs, cheese, milks.
- Deficiency: pernicious anemia, macrocytic anemia, megaloblastosis, and neurological dysfunction.
- Found to lower homocysteine levels in patients with cardiovascular disease.
- RDA: 200 ug for males, 180 ug for females, 100 ug for children, 35 ug for infants.
- Food sources: liver, kidney, spinach, broccoli, bran, peanuts, cabbage, lettuce, avocados, bananas, oranges, wholemeal breads, eggs, some fish, meat, poultry.
- Deficiency: macrocytic anemia, neural tube defects in fetuses whose mothers do not consume enough folate, megaloblastosis.
- Folic acid supplementation may mask the hematologic signs of pernicious anemia (vitamin B-12 deficiency), allowing the neurological symptoms of that condition to progress.
- Most effective of all vitamins in lowering homocysteine levels.
- RDA: 30-100 mg for males and females, 30 mg for children, 15 mg for infants.
- Food sources: organ meats, egg yolk, legumes, nuts.
- Deficiency: dermatitis, hair loss, hypercholesterolemia (occurs only when large amounts of egg whites are eaten, as uncooked egg whites contain a glycoprotein, avidin, which binds biotin, making it unavailable for absorption).
- RDA: 4-7 mg for males and females, 4-5 mg for children, 3 mg for infants.
- Food sources: meat, poultry, fish legumes, whole-grain cereals, milk, fruits, vegetables.
- Deficiency: neuritis of arms and legs, burning sensation of feet.
RECOMMENDED DAILY ALLOWANCES (RDAs), FOOD SOURCES, DEFICIENCY/EXCESS
- RDA: 800 mg for males, females and children. 600 mg for infants.
- Food sources: dairy products, whole grain cereals, leafy vegetables, legumes, nuts, broccoli, clams, oysters, salmon, sardines, shrimp.
- Deficiency: fragile bones, osteoporosis, bone pain, osteomalacia, paresthesias, increased neuromuscular excitability, muscle cramps, and tetany.
- Some calcium preparations are not well absorbed. If a calcium tablet left in vinegar for a period of 20 minutes dissolves, it should also dissolve in stomach acid.
- RDA: 800 mg for males, females and children. 500 mg for infants.
- Food sources: seafood, nuts, grains, legumes, cheese, meat, poultry, wholegrain cereals.
- Deficiency: renal hypophosphatemia, red cell hemolysis, severe muscle weakness, and opthalmoplegia.
- Excess: protein with high phosphorus content increases urinary calcium losses and vitamin B6 requirements.
- RDA: 350 mg for males, 280 mg for females, 170 mg for children, 60 mg for infants.
- Food sources: grains, nuts, meats, seafood, green leafy vegetables, milk, whole-grain cereals.
- Deficiency: increased neuromuscular excitability, muscle spasms, paresthesia, tetany, seizures, coma. Often seen in alcoholics, renal disease and fat malabsorption syndromes.
- RDA: 500 mg for males and females, 400 mg for children, 120-200 mg for infants.
- Food sources: table salt, baking powder, baking soda, milk, meat, fish, poultry, eggs.
- Deficiency: due to excessive and prolonged sweating or severe vomiting and diarrhea. Giddiness, nausea, apathy, cramps, exhaustion, vomiting, respiratory failure.
- RDA: 2000 mg for males and females, 1600 mg for children, 500-700 mg for infants.
- Food sources: milk, meat, fruits, cereals, vegetables, fruit juices.
- Deficiency: due to starvation or diuretic therapy. Slow ventricular repolarization.
- RDA: 10 mg for males, children and infants. 15 mg for females.
- Food sources: organ meats (liver, heart), wheat germ, egg yolks, oysters, fruits, dried beans, meat, fish, poultry, green vegetables, whole-grain and enriched cereals.
- Deficiency: fatigue, pallor, tachycardia, listlessness, exertional dyspnea, burning sensation of the tongue, glossitis, microcytic anemia, cheilosis.
- RDA: 150 ug for males and females, 120 ug for children, 50 ug for infants.
- Food sources: seafood, seaweed, iodized salt, dairy products, eggs, and bread.
- Deficiency: endemic goiter, cretinism.
- RDA: 1.5-4 mg for males and females, 1.5-2.5 mg for children, 0.1-1.0 mg for infants.
- Food sources: fluoridated drinking water.
- Deficiency: tooth decay.
- RDA: 1.5-3 mg for males and females, 1.2 mg for children, 0.6-0.7 mg for infants.
- Food sources: liver, nuts, legumes, oysters, shellfish, meats, and wholegrain cereals.
- Deficiency: neutropenia, microcytic anemia, depigmentation of skin and hair, neurological disturbances, lethargy.
- RDA: 70 mg for males, 55 mg for females.
- Food sources: seafood, whole grain cereals (depends on selenium content of the soil), meat, egg yolk, chicken, milk, garlic, Brazil nuts.
- Deficiency: uncommon, but severe deficiency could theoretically affect cardiovascular function, though could be masked by vitamin E.
- Antioxidant, works with vitamin E, some studies show reduced rates of specific cancers and cardiovascular disease.
- Toxic in high doses, accumulates in hair and nails.
- RDA: 15 mg for males, 12 mg for females, 10 mg for children, 5 mg for infants.
- Food sources: meat, liver, eggs, seafood, whole-grain products.
- Deficiency: growth retardation, hypogonadism, impaired taste and smell acuity, poor wound healing.
- Excess: Calcium, iron and zinc interfere with each other’s absorption.
Guidelines for Supplements
- Choose a preparation that provides close to 100% of the RDA for recognized nutrients.
- Choose a balanced multivitamin that contains several of the recognized nutrients, not just one or two, and avoid preparations that contain unrecognized nutrients or very small amounts of recognized nutrients.
- Ignore claims that a "natural" supplement is better than a "synthetic" one. Many synthetic supplements, such as folic acid and vitamin E, are actually more effective.
- Choose a preparation with an expiration date, since many nutrients will lose potency over time, and buy the least expensive supplement that meets all your needs.
- It is extremely important for the physician to ask patients about ALL dietary supplement intake, including herbal formulas, to avoid possibly dangerous megadoses or interactions with medications (vitamin E and anticoagulant therapy, for example) or diagnostic tests.
- Supplements should not substitute for a healthy diet as foods contain a wide variety of micronutrients that are likely to contribute to good health.
- Use of medicinal herbs is growing rapidly in the United States.
- Because of the paucity of research, relatively little is known of the efficacy and side effects of these herbs. They are currently considered dietary supplements and as such are not regulated by the FDA as drugs.
- Most US physicians have little training or information on the use of herbs.
- Examples of some commonly known herbs that have shown some promise:
- Echinacea (purple cornflower) – The number one selling herb in the United States, echinacea is taken to prevent colds, flu and infections. Studies have shown that it increases phagocytosis and promotes the action of lymphocytes, thus boosting the immune system. High doses may cause dizziness and nausea.
- Ephedra sinica (ma huang) – A central nervous system stimulant, it increases both systolic and diastolic blood pressure and heart rate. A form of ephedra has been used as a recreational drug, causing several deaths. Chinese ephedra is used as a bronchodilator and nasal decongestant. Ephedra is contraindicated for patients who are pregnant or lactating, or who have hypertension, heart disease or ulcers.
- Garlic (allium sativum) – The second best selling herb in the United States, garlic’s therapeutic properties have not been well established. There has been some evidence that garlic has an antibiotic effect, and it may reduce blood pressure and cholesterol if taken in large doses. Garlic may have an anticoagulant effect.
- Gingko biloba – This herb has been widely used in Europe to treat peripheral vascular disease, particularly of the cerebral circulation. Its active ingredients may help reduce capillary fragility, this preventing brain damage. It may also inhibit the formation of free radicals. Studies in Alzheimer’s patients have shown some improvement in memory. Side effects may include GI disturbances, allergic skin reactions and headaches.
- Ginseng – There are claims that ginseng boosts the immune system, increases memory, prevents stress-induced ulcers and vitalizes the body. Most research has been done in animals, with no significant human data.
- Goldenseal (hydrastis cenadensis) – The third best selling herb in the United States, goldenseal is not systemically absorbed, so claims of stimulating the immune system or masking a urine drug test for narcotics can have little basis in fact. Its active ingredient may have antibacterial properties and is used topically to treat canker sores.
- St. John’s Wort (hypericum perforatum) – Widely used in Europe as an antidepressant, St. John’s Wort is also taken for anxiety and sleep disturbances. Some initial research has shown some effectiveness for the treatment of depression, and controlled trials are currently underway. It may cause photosensitivity, especially in fair-skinned individuals.
- Saw Palmetto (Serenoa repens) – Used for benign prostatic hypertrophy, saw palmetto is widely used in Europe, where studies have shown increased urinary flow, decreased urinary frequency and reduced residual urine. With an action similar to finasteride, saw palmetto reduces uptake of testosterone and DHT and may actually lower the PSA.