Questions and answers:

1. How to quantitatively evaluate the nutritional value of protein?

Answer: The methods for evaluating the nutritional value of protein are:

a. The protein content in food: It is the basis for evaluating the nutritional value of food protein. Only when the protein content is high, other indicators will also be lower. Well, in order to meet the needs of the body.

b. The degree of protein digestion (protein digestibility): A high digestibility indicates that the protein is more likely to be digested and utilized, and its nutritional value is also high.

Nitrogen intake - (fecal nitrogen - original nitrogen in feces)

c. Protein biological value (BV): Its level mainly depends on the content and ratio of essential amino acids in food .

Storage nitrogen (absorbed nitrogen - (urine nitrogen - original urinary nitrogen)

d. Net protein utilization rate: Indicates the utilization of ingested protein in the body. It combines the Both aspects of digestion and utilization are included, so it is more comprehensive.

Net protein utilization rate = biological value

f. Protein efficacy ratio (PER) = grams of animal weight gain. /Grams of protein intake

g, Amino Acid Score (AAS) and Digestibility-Corrected Amino Acid Score (PDCAAS)

Amino acids necessary to make up protein at the site where protein is synthesized They must exist at the same time, and the lack of any one of them will affect the synthesis, so the composition of food protein amino acids is used to evaluate protein.

2. What is the amino acid score and what is its nutritional significance?

Answer: Amino acid score: Also called protein chemical score, the essential amino acid score model of the food protein under test is compared with the recommended ideal model or reference protein model. The amino acid with the lowest ratio is the first limiting amino acid. This minimum ratio is the amino acid score or chemical score of the test food protein. The score is the ratio of the essential amino acids in the food protein and the corresponding essential amino acids in the reference protein or ideal model.

Amino acid score = per. The content of a certain type of AA per gram of test protein (mg) / the content of certain AA per gram of reference protein (mg)

The content of amino acids in food protein can be compared with the relationship between the reference protein or per gram of nitrogen. Therefore, the amino acid score can reflect the relationship between protein composition and utilization. People of different ages have different amino acid score patterns, and different foods have different amino acid score patterns. Know the essential amino acids that they are deficient in, so as to reasonably mix the meals to achieve amino acid complementation, so that the amino acid pattern is closer to the needs of the human body, thereby improving the nutritional value of the mixed food protein.

3. The physiological significance of dietary fiber. What are they?

Answer: a. Enhance intestinal function and facilitate fecal discharge;

b. Control weight and lose weight;

c. Reduce blood sugar and Blood cholesterol prevents and treats hyperlipidemia and diabetes;

d. Prevents colon cancer;

e. Prevents and treats diverticular disease, compression disease, and gallstones.

4. . What are the aspects of heat energy consumption?

Answer: The consumption of heat energy includes basal metabolism, labor consumption (physical activity), and the special dynamic effect of food (food thermic effect)

5. Vitamins. What are its classification and main characteristics?

Answer: There are many types of vitamins, usually divided into two categories: fat-soluble vitamins and water-soluble vitamins according to their solubility.

Fat-soluble vitamins include A, D, E, and K

Water-soluble vitamins include B1, B2, PP, B6, pantothenic acid, biotin, lipoic acid, folic acid, B12, and C , P

The unique characteristics of vitamins:

a. Exist in natural food in its original form or in the form of a precursor that can be utilized by the body;

b. Most of them cannot be synthesized in the body, nor can they be stored in large amounts in tissues, and must be constantly supplied by food;

c. They are not raw materials for various tissues, nor do they provide energy;

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d. Although the daily physiological requirement is very small, it plays a very important role in regulating substance metabolism;

f. Often participates in enzymes in the form of coenzymes or prosthetic groups. Function;

g. Many vitamins have several compounds with similar structures and the same biological activities.

6. What are the factors that affect calcium absorption?

Answer: a. Absorption varies with the amount of intake and the amount required. When food contains high calcium, the absorption rate decreases accordingly. When the amount of calcium required by the body increases and the intake is less, the absorption rate increases accordingly;

b. Age, gender and physiological condition. The absorption rate decreases with age, the absorption rate of men is higher than that of women, and the absorption rate of women increases during pregnancy;

c. Factors in the diet that reduce calcium absorption. Phytic acid and oxalic acid, dietary fiber, some alkaline drugs (gastric antacid drugs), tetracycline, caffeine, 70-80% of the meal is not absorbed and is excreted in the feces;

d. Promotes calcium absorption factor. Vitamin D, lactose, protein.

7. What are the symptoms of zinc deficiency?

Answer: When children suffer from chronic zinc deficiency, the main manifestation is growth stagnation. In addition to growth stagnation, adolescents also suffer from delayed sexual maturity, underdevelopment of sexual organs, and underdevelopment of secondary sexual characteristics. If zinc deficiency occurs in pregnant women, it can affect the growth and development of the fetus to varying degrees and cause various malformations in the fetus. Whether in children or adults, zinc deficiency can cause loss of taste, loss of appetite, and pica. In severe zinc deficiency, low dark adaptation ability may occur even if there is a certain amount of vitamin A reserve in the liver. In acute zinc deficiency, the main manifestations are skin lesions and alopecia, but diarrhea, depression and eye damage also occur.

8. What are the main trace elements needed by the human body?

Answer: Iodine, iron, copper, zinc, manganese, cobalt, molybdenum, chromium, selenium, fluorine.

9. What are the main contents of community nutrition?

Answer: It includes not only purely natural science issues such as the nutritional supply and nutritional status evaluation of various groups of people in a limited area, but also discusses the population’s food structure, food economy, food culture, nutrition education, legal system and administration. Intervention and other social conditions and social factors that have a restrictive effect on residents' nutrition are combined with natural science. Mainly starting from social life, focusing on the social population as a whole, and combining nutritional science with social conditions and social factors to study and solve residents' nutritional problems.

10. What are the main methods of dietary surveys?

Answer: a. Accounting method. Including: statistics on food consumption, number of dining days, average daily food consumption per person, and calculation of nutrient supply in each person's daily diet.

b. Review inquiry method. Including: 24-hour dietary review method, food frequency questionnaire, and dietary history method.

c. Weighing method.

Specific steps: 1. The main and non-staple foods for each meal every day should be weighed first and then cooked; 2. Weigh the cooked food weight and remaining cooked food weight (including the weight of discarded residue) after the main and non-staple food are out of the pot, and calculate the main weight of each meal. , the net raw weight of non-staple food; 3. Based on the number of days of investigation, find the average daily intake of various main and non-staple foods per person; 4. Based on the results, further calculate the dietary composition and heat energy and protein sources in various categories The percentage of food, the percentage of heat production of the three major nutrients and the percentage of protein sources to evaluate whether the dietary composition and heat distribution are reasonable and the quality of protein in the diet; 5. Investigation of food cooking methods; 6. Kitchen and canteen hygiene investigation.

d. Chemical analysis method

11. What are the nutritional characteristics of cereal foods?

Answer: a. It is the main source of dietary calories for the Chinese people (70);

b. It is an important source of protein (about 8);

c , is an important source of B vitamins. The germ contains vitamin E and does not contain vitamin A, vitamin D and vitamin C;

d. It is a low-fat food (2), and its fatty acid composition is mainly human Essential fatty acid linoleic acid (60);

e. Grain husk and grain germ are rich in inorganic salts (K, Ca, Mg, P, Fe, Zn);

12. What are the nutritional characteristics of milk and dairy products?

Answer: (1) Milk: a. The protein content is 3-4, and the digestion and absorption rate is 87-89. Its essential amino acid content and composition are similar to eggs, and its utilization rate is high. It is a high-quality protein. The composition ratio of casein and albumin in milk is exactly opposite to that of human milk; b. The fat content is 3-5, the particles are small, and the digestion and absorption rate is high; c. The carbohydrate contained is lactose (4-5), and its content is higher than that of human milk. It is low in milk, promotes the growth of intestinal lactic acid bacteria, and can also promote the absorption of calcium and inorganic salts; d. It is a rich source of minerals, mostly calcium, phosphorus, and potassium, but insufficient in iron; e. Contains various minerals needed by the human body. A variety of vitamins, the content of vitamin A and vitamin C is related to animal feed and season.

(2) Dairy products: a. Milk powder. Full-fat milk powder has good solubility and has little impact on the properties of protein, milk color, aroma and other nutrients. The fat content is around 26, which is suitable for ordinary people to eat. Skim milk powder is a high-protein and low-fat nutritious food. It is suitable for the elderly and people with obesity and high blood lipids. Formula milk powder appropriately adjusts and improves the nutritional composition of milk to make it more suitable for infants, pregnant women, and middle-aged and elderly people. b. Yogurt. All nutrients of milk are retained, and protein and fat become easier to digest; the utilization rate of calcium, phosphorus, and iron is greatly improved; lactic acid can inhibit the reproduction of intestinal bacteria, increase appetite, and promote gastrointestinal peristalsis; maintain the balance of intestinal flora and increase Beneficial bacteria inhibit spoilage bacteria. c. Condensed milk. The sugar content is high (above 40), and the content of protein, vitamins, inorganic salts and other nutrients after dilution with water is relatively low, so it is not suitable for feeding babies, but it is suitable for long-distance travelers or field workers. d. Cream. It contains more than 80% fat and less than 16% water content. It is mainly used for meals and making bread and pastries.

13. What aspects should be paid attention to when preparing meals for young children?

Answer: Early childhood is still a stage of rapid growth and development. According to nutritional surveys, young children often have low intakes of energy, protein, calcium, vitamin A, riboflavin and vitamin C. Iron deficiency anemia, rickets, riboflavin deficiency, low weight and low height are also common.

a. Protein. Children should have a certain amount of milk, lean meat, poultry, fish, soybeans and soy products and other foods with high protein nutritional value in their daily diet. High-quality protein should account for more than 1/2 of the total protein in the diet.

b. In order to solve the deficiencies of minerals and vitamins, special emphasis should be placed on the diversity of dietary varieties. Especially eat more yellow and green vegetables and fresh fruits.

c. It is not advisable to eat too much pure sugar and pure fat foods.

d. Pay attention to cooking methods. It is necessary not only to keep the nutrients from being destroyed, but also to diversify the color, flavor and shape of the meals to increase the appetite of young children.

e. Eat regularly, not be picky about food or have a partial eclipse, and cultivate good eating habits in children.

14. What are the characteristics of nutrition for pregnant women?

Answer: a. Energy. In addition to maintaining the energy required for themselves, pregnant women also need to bear the energy required for the growth and development of the fetus and the growth of the placenta and maternal tissues. The energy supply in early pregnancy is the same as that of non-pregnant women. The energy supply in pregnancy, middle and late pregnancy is increased by 200kcal per day based on the energy supply of non-pregnant women.

b. Protein. Based on the protein supply of non-pregnant women, the supply should be increased by 15g per day in the second trimester and 25g per day in the third trimester. In addition, high-quality protein in the diet should account for more than 1/2 of the total protein.

c. Fat. There should be an appropriate amount of fat in the diet, including saturated fatty acids, n-3 and n-6 ??polyunsaturated fatty acids, to ensure the needs of the fetus and itself. However, pregnant women's blood lipids are higher than usual, so they should not consume too much fat. It is generally believed that the energy provided by fat should account for 25-30% of the total energy.

d. Calcium, iron, zinc, iodine. Calcium. Almost all the calcium needed during pregnancy is accumulated in the fetus in the last three months to meet the needs of the growth and development of the fetus's bones and teeth. In addition, the mother's body also needs to store some calcium for use during lactation. The Nutrition Society recommends daily intake during the second trimester. 1000mg, 1500mg in late pregnancy. Pregnant women should increase calcium-rich foods. If the dietary intake is insufficient, they can also supplement with some calcium preparations; iron. Iron deficiency in early pregnancy is related to premature birth and low birth weight. Iron deficiency during pregnancy can also affect newborns. The amount of iron stored in the liver causes iron deficiency or iron deficiency anemia in babies early after birth. The Chinese Nutrition Society recommends that the iron supply for pregnant women is 28 mg per day during the second and third trimesters of pregnancy. Zinc, maternal zinc supplementation can promote fetal growth and development and prevent congenital malformations. The recommended dietary zinc supply is 20 mg in the second and third trimester of pregnancy. Iodine is a necessary nutrient for the synthesis of thyroxine, and thyroxine can promote protein synthesis and promote fetal growth and development. It is very important for the normal development of the brain. The recommended daily dosage for pregnant women is 150 micrograms in the first trimester, and 150 micrograms in the second and third trimesters. 175 micrograms.

e. Vitamins. Vitamin A deficiency in pregnant women is associated with intrauterine growth retardation, low birth weight and premature birth. Excessive intake can lead to spontaneous abortion and congenital malformations (1000 micrograms of retinol equivalent in the second and third trimesters of pregnancy). Vitamin D deficiency is associated with osteomalacia and osteomalacia in pregnant women. Neonatal hypocalcemia is related to tetany. Due to pregnancy reactions and metabolic changes in early pregnancy, sufficient water-soluble vitamins should be supplied. Vitamin B1, B2, B6 and vitamin C supplementation can help reduce vomiting and abnormal taste during pregnancy. Supplementing 400 mcg/day of folic acid before and during early pregnancy can effectively prevent the occurrence and recurrence of most neural tube defects.

15. What are the basic meals in the hospital?

Answer: a. Regular meals. It is a meal prepared by changing the cooking methods or changing the food texture according to the pathological and physiological needs of different diseases. The nutrient content is generally inconvenient.

b. Special treatment meals. It is a meal set based on the regular meal by adjusting the nutritional components or preparation methods of the meal.

c. Experimental diet and metabolic diet for diagnosis. It is a special diet used for disease diagnosis or auxiliary examination or metabolic research.

16. What are the dietary principles for preventing and treating fatty liver?

Answer: a. Control energy intake: generally 30-35kcal/kg;

b. Properly increase protein: a high-protein diet (1.5-1.8g/kg) is recommended;

c. Reduce sugar and sweets;

d. Control fat and cholesterol. The total amount of food and cooking oil supplied throughout the day should not exceed 40g. Foods with high cholesterol should be controlled in appropriate amounts;

e. Supplement vitamins, minerals and dietary fiber.

17. What are the dietary principles for preventing and treating high blood pressure?

Answer: a. Quit smoking and drinking;

b. Achieve and maintain ideal weight or appropriate weight, and pay special attention to central obesity;

c. Limit sodium intake. For patients with mild hypertension or those with a family history of hypertension, 3-5g of salt per day (equivalent to 15-25ml of soy sauce); for those with moderate hypertension, 1-2g of salt per day (equivalent to 5-10ml of soy sauce); Patients with severe hypertension or rapidly progressive hypertension should adopt a salt-free diet;

d. Increase potassium intake, and the K/Na ratio should ideally reach 2:1;

e. Reduce fat and cholesterol intake, fat accounts for less than 25% of total calories, and daily cholesterol is limited to less than 300mg;

f. Limit saturated fatty acids (S), and increase polyunsaturated fatty acids (P) appropriately. Make the daily P/S value reach 1-1.5;

g. Appropriately increase magnesium intake, especially for patients who use diuretics such as diuretic acid and furosemide.

h. Eat foods rich in potassium, calcium, vitamins and trace elements. Foods rich in high-quality protein, low in fat, and low in cholesterol;

i. High-sodium foods, high-fat, and high-cholesterol foods are prohibited or used sparingly.

18. How to formulate nutrition and health education projects?

Answer: (1) Determine the education objects according to the educational purpose;

(2) Determine the educational content;

(3) Determine educational methods and forms to develop leaders, train backbones, and mobilize the masses; develop a variety of educational methods.

19. What is the main function of carbohydrates?

Answer: a. Provide energy;

b. Make up important substances of the human body;

c. Transmit information;

d. Lubrication;

e. Protect proteins from being digested by proteases;

f. Control the permeability of cell membranes;

g. Save protein;

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h. Anti-ketogenic effect;

i. Detoxification effect.

20. What is the meaning of glycemic index?

Answer: Glycemic index refers to the value calculated by comparing the area under the blood sugar reflection curve after eating 50g of the test food in the fasting state with the same amount of reference food (glucose or white bread), that is, the area under the former reflection curve Divide the latter by the area under the curve and multiply by 100.

21. What are the physiological functions of fat?

Answer: a. Supply and store energy;

b. Form biofilm;

c. Supply essential fatty acids;

d , carry fat-soluble vitamins and promote their digestion and absorption;

e. Increase food deliciousness and satiety;

f. Maintain body temperature and support various organs;

g. Endocrine effects.

8. What are the main functions of vitamin C?

Answer: a. Promote the formation of connective tissue;

b. Antioxidant effect;

c. Promote the absorption of iron in food;

d. Improve immune function;

e. Anti-cancer effect.

22. What are the functions of vitamin E?

Answer: a. Antioxidant effect;

b. Maintain the integrity of red blood cells and promote the synthesis of red blood cells;

c. Promote the synthesis of coenzyme Q, Regulates energy production from proteins, lipids, and carbohydrates;

d. Participates in DNA biosynthesis;

e. Impact on eyes;

f. Effect on the environment Anti-pollution effect;

g. Anti-infertility effect;

h. Vitamin A-saving effect.

23. What are the physiological functions of minerals?

Answer:

24. What are the nutritional characteristics of eggs and egg products?

Answer: a. Protein (13-15), concentrated in egg white, contains all the amino acids needed by the human body, and the amino acid pattern is close to that of the human body. The digestion and absorption rate is 98-100, which is the most ideal food. One of the natural high-quality proteins;

b. All fats are concentrated in the egg yolk (11-15). The egg yolk has high cholesterol and is rich in lecithin;

c. Vitamin A and vitamin A in the egg yolk D is rich.

25. What are the nutritional characteristics of school-age children?

Answer: a. Energy. Children have strong growth and development, high basal metabolic rate, and are lively and active, so they need more energy, but the energy intake should not be higher than their energy consumption;

b. Protein. Children's protein requirements increase with growth and development, especially muscle development;

c. Minerals. Due to the rapid growth of bones and circulating blood volume, children have a high demand for minerals, especially calcium, phosphorus, and iron. Other trace elements such as iodine, zinc, and copper must also be consumed in adequate amounts.

d. Vitamins. Vitamins A and D are closely related to growth and development and must be supplied in sufficient amounts. Thiamine, riboflavin and niacin are related to various metabolisms in the body and must also be supplied in sufficient amounts.

26. From what aspects are nutrition survey results evaluated?

Answer: After the dietary survey, based on the obtained average intake of various foods per person and the food composition table, calculate: a. The average daily intake of nutrients per person; b. Ratio of the average daily intake of nutrients to the recommended appropriate intake; c. Percentage of energy distribution between three meals, recommended for adults, breakfast, lunch, and dinner = 30:40:30, recommended for children, breakfast, lunch, snack, and dinner =25:35:10:25; d. The percentage of intake of the three major energy nutrients, recommended protein accounts for 10-14, fat accounts for 20-30, and carbohydrate accounts for 60-70; e. The percentage of protein sources. High-quality protein should be no less than 1/3 of the total intake; f. Calcium-phosphorus ratio. 2:1 for infants, 1.5:1 for children and the elderly, 1:1 for teenagers, 1:1-1:1.5 for adults; g, cholesterol intake; h, intake of different types of food. Then combine the clinical nutrition examination and nutritional biochemical examination results to make a comprehensive evaluation.

27. What are the common causes of vitamin deficiency?

Answer: a. Insufficient supply;

b. Improper food storage and cooking methods;

c. Malabsorption;

d. Inhibition of intestinal bacterial growth;

e. Increased demand;

28. What are the effects of malnutrition during pregnancy on the mother and fetus?

Answer: Impact on the mother: a. Cause nutritional deficiency diseases: nutritional anemia (iron, folic acid, VB2), osteomalacia (calcium, VD), dystrophic edema (protein, VB1 ) b. Pregnancy complications; c. Pregnancy-induced hypertension syndrome (maternal obesity, excessive sodium intake, insufficient protein, calcium, zinc, magnesium, and VB6 intake)

Effects on the fetus: a. Low birth weight (low weight before pregnancy, slow weight gain during pregnancy, low maternal plasma total protein and albumin, maternal anemia, VA, VB1, VB2 deficiency, heavy drinking or smoking in pregnant women, premature birth). b. Preterm infants and infants who are small for gestational age; c. Increased perinatal neonatal mortality; d. Impaired brain development (protein); e. Congenital malformations: (deficiency of zinc, iodine, folic acid, excess VA).

29. What are the main principles of food fortification?

Answer: In 1987, the Codex Alimentarius Commission stipulated the addition of essential nutrients to food. The basic principles of fortification are: to compensate for losses (recovery) during food processing, storage and handling; to ensure Nutrient balance in food imitations or substitutes; compensating for changes in nutrient content due to natural causes (standardization); increasing the nutrient content of the food itself (fortification); providing a balanced intake of micronutrients in special circumstances (formulas).