1、 Definition and types of obesity
（1） Definition of obesity
Obesity: refers to the body contains too much fat tissue.
Generally, the body fat content of adult women is more than 30%, and that of adult men is more than 20% - 25%.
The normal range of BMI in developed countries is 20-25, with an average of 22;
In developing countries, the normal BMI is 18.5, and the recommended BMI is 20.
Who puts forward that the BMI of the world is 20-22.
BMI classification:
Normal value: 18.5-25
Class I hazard value: 17.5-18.5 and 25-30
Class II hazard value: 161-7.5 and 30-40
The third level hazard value is below 16 and above 40.
The relationship between body fat content and BMI:
Body fat content in men (%) = 1.215bmi-10.13
Female body fat content (%) = 1.48bmi-7
（2） Types of obesity
1. By cause
Simple obesity: normal endocrine system;
Secondary obesity: endocrine abnormality.
Mainly simple obesity, more than 95%.
2. Fatty tissue morphology
Early obesity: the number of fat cells increased abnormally;
Obesity in later years: normal number of fat cells, but hypertrophied cells
3. According to the body shape of obesity
Abdominal obesity (seen in men)
Fat buttocks (seen in women)
Waist to hip ratio is very important!
Generally, the waist must be less than the hip by 15%.
The harm of obesity to the body
"Obesity is the hotbed of disease"
Diabetes, hypertension, gallstones
Infertility, heart disease, arthritis, gout
The incidence rate of incidence rate incidence of coronary heart disease is higher than that of normal persons, 2~5 times of coronary heart disease are higher than that of normal persons. The incidence rate of hypertension is 3~6 times higher than that of normal persons, the incidence rate of diabetes is 6~9 times higher than that of normal persons, and the incidence of cardiovascular and cerebrovascular diseases is higher than 2~3 times.
（1） Predisposition to diabetes
Obesity is the most important risk factor for diabetes!
Diabetes is the patent of almost all obese people. In the research, it is pointed out that diabetes is caused by high carbohydrate and high calorie diet. 70-85% of people lose weight, and their condition has improved.
According to epidemiological statistics, obese people are more than three times more likely to have diabetes than normal people, which is related to the abnormal insulin secretion. Insulin is secreted by islet B cells and plays an important role in regulating blood glucose level. The increase of insulin secretion and fat synthesis will lead to obesity, which will increase the burden of islet B cells. Over time, it will lead to islet dysfunction, and the relative lack of insulin secretion, which will lead to the abnormal increase of blood glucose level and the formation of diabetes.
（2） Risk of cardiovascular disease
The BMI with the lowest risk of cardiovascular disease was 23.
The main characteristics of fat metabolism in obese people are the increase of plasma free fatty acids, total cholesterol, triglycerides and LDL, and the decrease of HDL. A large number of adipose tissue deposited in the organs, blood vessels and other parts of the human body, which affect the functional activities of cardiovascular, cerebrovascular, hepatobiliary digestive system and respiratory system, and then lead to high-fat blood, hypertension, atherosclerosis, myocardial infarction and other diseases.
With the aggravation of obesity, the blood flow of systemic circulation and pulmonary circulation increased, the myocardial oxygen demand increased, and the myocardial load increased significantly, leading to heart failure.
Obesity patients have 30% to 50% hypertension, and the incidence rate of hypertension is 3 times higher than that of non overweight people.
（3） Increased tumor susceptibility
The levels of trace elements such as serum iron and zinc in obese subjects are lower than those in normal persons. These trace elements are closely related to immune active substances. Therefore, the immune function of obese people is reduced and the incidence rate of cancer is increasing. Some people have investigated and analyzed the moderately obese people. The results show that the probability of cancer in men is 33% higher than that in normal people, mainly including colon cancer, rectal cancer and prostate cancer. The probability of cancer in women is 55% higher than that in normal people, mainly including uterine cancer, ovarian cancer, cervical cancer, breast cancer, etc.
The occurrence of breast cancer and uterine cancer in women is closely related to the abnormal increase of estrogen level caused by obesity. If the diet is reasonable and nutritious, and maintain a standard weight, the incidence rate of cancer in animal is reduced. It can be seen that obesity can increase the risk of cancer
（4） Abnormal function of liver, gallbladder and lung
Because of the abnormal activity of lipid metabolism, a large number of free fatty acids are produced in the body of obese patients. After entering the liver, fat can be synthesized, resulting in fatty liver and abnormal liver function.
The incidence rate of cholelithiasis in obesity patients is significantly higher. Compared with those with normal weight, the increase of male is 2 times, and that of female is 3 times. It is mainly due to the increase of cholesterol concentration in blood and bile and the deposition of cholesterol gallstones.
Because of the increase of fat in abdominal cavity and chest wall, the relative weakness of muscle, the respiratory movement was blocked, the pulmonary ventilation was poor, pulmonary hypertension and right heart load were increased. At the same time, because of the increase of circulating blood volume and other reasons, it will induce obesity, pulmonary heart syndrome.
2、 Development of functional diet food
The methods of prevention and treatment of obesity include drug therapy, exercise therapy and diet therapy. Drug therapy mostly through heat, so that the metabolic rate rise to achieve weight loss. However, most of these drugs have relatively large side effects, the general people should not take them for a long time, and the most basic way to lose weight is through exercise and diet.
Principles of diet food preparation
1. Limit total heat
According to the degree of obesity, there are three types: light (more than 10% - 20% of the standard weight), medium (more than 20% - 30% of the standard weight) and heavy (more than 30% of the standard weight).
If the daily heat requirement of normal physiology is 10080kj as an example, the caloric limit of light obesity is 80% (8064kj), medium obesity is 60% (6048kj), heavy obesity is 40% - 60% (4032-6048kj). It is easy to feel tired, tired and depressed in heavy cases due to excessive heat restriction, which should be determined according to the situation
2. Limit fat
The subcutaneous fat of obese people is too much, which is easy to cause fatty liver, cirrhosis, hyperlipidemia, coronary heart disease, etc. Therefore, the daily fat intake should be controlled at 30-50g, mainly plant oil, and animal oil should be strictly limited.
3. Limit carbohydrates
Carbohydrates can be converted into fat in the body, so it is necessary to limit the intake of carbohydrates, especially to use less or avoid foods with more monosaccharide and disaccharide. It is generally believed that carbohydrate provides 45% - 60% of the total heat energy, and staple food is controlled at 150-250g per day. However, carbohydrates can oxidize fat into carbon dioxide and water. If the intake is too low, the oxidation of fat is not thorough and ketone body will be formed, which is not conducive to health. Therefore, the reduction of carbohydrates should be moderate.
4. High quality protein supply
Protein has a special dynamic function, and its requirement should be slightly higher than that of normal people. Therefore, the daily protein requirement of obese people is 80-100g. We should choose foods with high physiological value, such as milk, eggs, fish, chicken, lean beef, etc.
5. Supply a variety of inorganic salts and vitamins
Inorganic salt and vitamin supply should be rich and diverse to meet the physiological needs of the body. If necessary, supplement vitamins and calcium agents to prevent the lack. Salt is hydrophilic, which can increase the water storage in the body and is not conducive to the control of obesity. The daily salt content is 3-6g.
6. Adequate supply of dietary fiber
Dietary fiber can delay gastric emptying time, increase satiety, reduce food and calorie intake, reduce weight and control obesity, promote intestinal peristalsis and prevent constipation. Wheat bran and rice sugar are rich in dietary fiber, spirulina and edible fungus.
7. Restrict purine containing foods
Purine can increase appetite, increase the intermediate metabolic burden of liver, kidney and heart, which should be limited in diet. Animal viscera, beans, chicken soup, broth and other high purine food should be avoided.
3、 Development of diet food and precautions
1. Develop special food for weight loss mainly by regulating diet
According to the requirements of low calorie, low fat, high protein and high dietary fiber of diet food, the daily diet of obese patients is produced by using oats, buckwheat, soybeans, whey, wheat germ powder, konjac, yam, sweet potato, spirulina and other raw materials with weight-loss function, and the effect of weight-loss is achieved through diet.
Oat has soluble dietary fiber, konjac contains glucomannan, soybean contains high quality protein, soybean saponin and oligosaccharide, wheat germ powder contains dietary fiber and rich vitamin E, which can meet the nutritional needs of obese people and reduce weight. Sweet potato and yam are rich in mucoprotein, which can reduce the accumulation of subcutaneous fat. Spirulina is widely used as a weight-loss food in Germany, which can be added to weight-loss food.
2. Development of diet food with Chinese herbal medicine
There are many raw materials that can be used as weight-loss food in food and medicine food dual-purpose plants. Some of these medicine food dual-purpose products have the effect of clearing away heat and dampness, such as tea, Kuding tea, lotus leaf, etc.; some can reduce blood lipid; some have the effect of supplementing nutrition, promoting fat decomposition, etc.
From the perspective of modern nutrition, these raw materials are rich in dietary fiber, mucus protein, plant polysaccharides, flavonoids, saponins and bitter elements, etc., which can regulate the metabolism of human body, inhibit the absorption of sugar and fat, accelerate the metabolism of fat, and achieve the effect of weight loss.
3. Diet food with special functional ingredients
With the development of science, some chemicals with obvious effects on obesity have been found gradually, some of which can be used in functional food. Diet food shall not be added with drugs.
Substances with weight loss function
（1） Fat metabolism regulatory peptide
The peptide is obtained by enzymolysis of protein mixtures such as milk, fish, soybean and gelatin. The peptide has 3-8 amino acid bases, mainly composed of "val - val - cheese - preserved", "val - cheese - preserved" and "val - cheese - bright".
1. Inhibit fat absorption
When edible oil at the same time, it can inhibit the absorption of fat and the rise of serum triglyceride. The mechanism of action is related to the inhibition of lipolytic enzyme, so it has no effect on the absorption of other nutrients and fat soluble vitamins.
2. Block lipid synthesis
When eating high sugar food at the same time, the increase of fat tissue and weight is inhibited due to the obstruction of fat synthesis.
3. Promote fat metabolism
When ingested with high-fat food at the same time, it can inhibit the increase of fat content in blood, fat tissue and liver tissue, and also inhibit the increase of weight, effectively preventing obesity.
（2） Konjac flour and glucomannan
Glucomannan is the enzymatic refined product of konjac flour.
It can significantly reduce body weight and fat cell size.
Some scholars used konjac flour to raise rats (9 rats in each group). According to the body weight, the small dose group was 1.9mg/g, the large dose group was 19mg / g, and they were fed with high fat and high nutrition feed. After 45 days, they were compared.
Compared with the control group, the body weight of the high-dose group and the low-dose group decreased significantly, but there was no significant difference between the high-dose group and the low-dose group. Under high power microscope, the number of fat cells in each field was significantly more than that in the control group, while the cell volume was significantly smaller than that in the control group.
（3） Oolong tea extract
The functional components extracted from Oolong tea are mainly theaflavins, catechins and their derivatives. In addition, it also contains amino acids, vitamin C, vitamin E, tea saponin, flavonoids, flavonol and many other complex substances.
（4） L-carnitine
Because L-carnitine has many nutritional and physiological functions, it has been regarded as an essential nutrient for human body.
（5） Buckwheat
The biological potency of buckwheat protein is higher than that of rice and wheat; the content of fat is 2% ~ 3%, with oleic acid and linoleic acid in the majority; various vitamins and trace elements are also rich; it also contains more rutin and flavonoids, which can maintain the elasticity of capillary and reduce the permeability of capillary. Often eat buckwheat noodles, high cake and other pasta has obvious effect of reducing fat, sugar and weight.
（6） Sweet potato
The content of protein, fat and carbohydrate is lower than that of grain, but its nutritional content is appropriate and its nutritional value is better than that of grain. It is rich in carotene, B vitamins and vitamin C. Sweet potato contains a lot of mucus protein, which can prevent atherosclerosis, reduce blood pressure, lose weight and anti-aging. Sweet potato is also rich in collagen vitamins, which has a special role in preventing the transformation of remaining carbohydrates into fat. This kind of collagen dietary cellulose is not absorbed in the intestine. After absorbing water, it softens the stool, facilitates excretion and prevents colorectal cancer. After collagen fiber combined with bile, it can reduce serum cholesterol and gradually promote the elimination of body fat.
