Substances with nutritional function in food, that is, substances that can be obtained from food and used in human body, have the functions of forming tissues, regulating physiological functions and supplying energy.
1 lipid; ② protein; 3 sugar; 4 inorganic salts; 5 vitamins; 6 dietary fiber; 7 water
2. Try to describe the nutritional value characteristics of vegetables and how to make rational use of them.
Vegetables can be divided into leafy vegetables, rhizomes, melons, eggplant, fresh beans and flower buds, and the nutrient content varies greatly due to different species.
1, protein: The content of protein in most vegetables is very low, generally 1%-2%, and the average content of fresh beans can reach 4%. The contents of lysine and methionine in essential amino acids are low.
2. Carbohydrates: sugars (carrots, tomatoes, pumpkins, sweet potatoes and various fruits), starch (rich in root vegetables) and dietary fiber.
3. Vitamins: Vitamin C, carotene, vitamin B2 and folic acid are abundant.
4. Minerals: Calcium, phosphorus, iron, potassium, sodium, magnesium and copper are the main sources of dietary inorganic salts. 5. Aromatic substances: organic acids and pigments.
6. Some enzymes: bactericidal substances and physiologically active components with special functions.
7. Fat: The fat content of vegetables is extremely low, generally not exceeding 1%.
1. Ensure that the amount of vegetables eaten every day should reach 300 g ~ 500 g, that is, 62 to 1 kg.
2. Make sure that half of the vegetables you eat every day belong to dark vegetables.
When choosing vegetables, try to choose fresh seasonal vegetables, because the content of vitamin C in fresh seasonal vegetables is relatively high.
We should choose a variety of vegetables in life, because different vegetables have different nutritional characteristics, so choosing a variety of vegetables can learn from each other's strong points and be beneficial to our health.
5. Pay attention to increasing the intake of cruciferous vegetables, fungi and algae vegetables in life.
6. Eat less pickles. The salt content in pickles and pickles is relatively high, and the vitamin C content in pickles is very low.
7. Eat vegetables with more starch, such as potatoes, taro, yam, etc., and reduce staple foods appropriately to avoid excessive energy intake.
3. What are the common methods of dietary survey?
The commonly used dietary survey methods can be divided into retrospective and prospective.
The former category includes: 24-hour dietary review method, dietary history method and food frequency questionnaire method; The latter category mainly refers to diet recording method, including weighing method, bookkeeping method and chemical analysis method.
According to the scope of investigation, dietary survey methods can be divided into three types: weighing method, bookkeeping method and inquiry method (24-hour dietary review method, dietary history method and food frequency questionnaire method, which are suitable for special population survey). Except some food frequency questionnaires are qualitative analysis, other methods are quantitative analysis.