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6.1 History of Hospital Meals

Since the Meiji Restoration, the modernization of medicine and medical care has also had an impact on hospital food. Under the influence of Anglo-American and German medicine, the concept of patient meals based on modern nutritional science gradually came to be discussed. In 1888 (Meiji 21), Chiyokichi Hirano of Juntendo Hospital was the first to introduce Western-style meals for the sick, and published “A New theory of diet therapy” to include Japanese meals. Yukichi Fukuzawa founded Keio University Hospital with Dr. Shibasaburo Kitazato and opened the “Research Institute of “Diet Therapy “in 1926 (Taisho 15). They began a full-scale study of meals for the sick and formulated the concept of therapeutic meals, and the results of this study were developed into meals for hospitalized patients.

However, the institutionalization of meals for hospitalized patients was largely due to the guidance of the United States after the war. In 1947 (Showa 22), the GHQ surveyed hospitals and pointed out to the government the need for improvement of medical care in Japan, which led to the enactment of the “Medical Service Act” the following year. As a result, medical institutions were established so that all citizens could receive medical care based on modern medicine, and hospital meals and hospital dietitians were included as part of this system.

6.1.1 From a Complete Meal System to the Standard Meal System

In 1950 (Showa 25), the “Complete Meal System” was formulated with the aim of ensuring that hospitalized patients would be able to obtain an adequate amount of nutrition from hospital meals alone, without having to bring supplementary food from home. In those days, when a patient was admitted to a hospital, it was common for him or her to be admitted with a pot and bedding (mattress, blanket, etc.). It was also common for hospitalized patients and their families to cook in a corner of the hospital room or in the corridor, and to bring in meals from home, without any hygiene or nutritional control. The complete meal system ensured that the patients would receive the necessary amount of nutrition per day from hospital meals alone. It would be unthinkable today, but all hospitalized patients were uniformly provided with 2400 kcal of food. The purpose of this policy was the strong desire of those involved in nutrition to improve the nutritional status of hospitalized patients, who were sickly and weak, by securing food for them on a priority basis during the severe food shortage after the war, when many people were dying of starvation and malnutrition. In a manner of speaking, all hospitalized patients were in a state of nutritional deficiency, and the meals were designed to solve this problem.

Later, as society stabilized and food supplies became dependable again, hospital food changed from securing quantity to improving quality, and in 1958 (Showa 33), the “Complete Meal System” was changed to the “Standard Meal System”. Hospital meals were allowed to be added to medical service fees if they satisfied certain criteria set by the government, and hospital meals became an integral part of medical care as well as a qualitative improvement. The qualitative improvement of hospital meals at that time involved reducing the overemphasis on staple foods, such as a large amount of rice. Specifically, it aimed to improve the quantity and quality of side dishes, increase the intake of animal protein, and increase the intake of protein, fat, and even vitamins and minerals. Therefore, in the qualitative assessment, the most important factor was the “animal protein ratio” from meat, fish, eggs and dairy products to the total protein intake provided. The higher the proportion of animal products, the higher the quantity and quality of protein, and the higher the intake of vitamins and minerals. However, raising the “animal protein ratio” increased the cost of foodstuffs, so there was a battle between hospital managers who wanted to lower the cost of meals and nutritionists who wanted to ensure quality. However, there was a challenge to this index. Vegetarian hospitals, which had adopted vegetarian meals for religious reasons, were unable to raise this ratio and could not meet the standard for standardized feeding even though they provided finely-tuned meals using alternative foods such as soybeans.

6.1.2 Report on the Calorific Requirements of Hospital Meals for General Patients

In 1973 (Showa 48), the National Dietetic Council abolished the 2400 kcal nutrient amount that had been required up to that time, and changed the content so that meals could be provided that were closer to the appropriate amount for each individual patient. In other words, the “Caloric Requirements for Patients (15 years and older) on General Meals in Hospitals” was issued. The calorific value for patients provided with general meals in hospitals was calculated by adding a correction factor of 0.6 to the life activity index of ‘nutritional requirements’ for healthy people by sex and age. The intensity of activities of daily living of hospitalized patients was estimated to be 60% of that of healthy people leading their ordinary lives. Originally, there was a principle that meals for the sick should be determined on an individual basis, considering not only the sex and age of the patient, but also the patient’s individual activity level, nutritional status, and the effects of his or her illness. However, in reality, hospitalized patients were managed as a group, similar to the practice for school lunches or industrial lunches, and individual attention was not possible.

6.1.3 Start of the Inpatient Meal Treatment System

In 1994 (Heisei 6), the “Standard Meal System”, which was intended to ensure the quality of hospital meals, was abolished because its purpose had been achieved, and a new “Inpatient Meal Treatment System” was started, which included a partial flat-rate co-payment for meals. At that time, the importance of determining the amount of nutrition for each patient was pointed out, taking into consideration the patient’s individual medical condition and nutritional status. The new system aimed to provide meals for sick people that corresponded to the individual needs of each patient, but unfortunately, the specific method for doing so was not provided at this time either. In other words, it was not clear how to respond to each individual patient, and it was necessary to wait until the revision of the law in 2000 (Heisei 12) to develop hospital food service into a part of clinical nutrition management as we know it today.

6.2 Hospital Meals Are Bad

There was a difficult problem that had to be solved before hospital food could be nutritionally managed in accordance with the needs of individual patients. This was to deal with complaints that hospital meals were bad. Malnutrition was observed in many hospitalized patients, and even when it was pointed out that the solution to this problem was important in terms of medical care, the answer from many people was that it was not a problem in terms of nutritional management, but that it was because the hospital meals were bad and patients could not eat them. As the malnutrition of the postwar period was resolved and people became more affluent, hospitalized patients began to chant, “Hospital meals are bad, bad, bad,” and there was a strong demand for hospital food to be tasty.

Why was it claimed that hospital meals were ‘bad’, yet this problem had been neglected?’

In general, if a restaurant serves bad meals, customers will stop coming and the restaurant just ‘will eventually close.’ Therefore, cooks think of taste first and devise ways to improve it, and managers make efforts to improve service by scouting cooks who can prepare delicious food. Hospital meals were positioned as part of the treatment from the time of the Medical Service Act set up after the war, and when the Standard Meal was set up in 1958 (Showa 33), hospital meals were included in the social insurance medical fee in 1961 (Showa 36) an additional charge for special treatment meals was approved. Special meals subject to supplementation were defined as “therapeutic meals with nutritional amounts and contents corresponding to the patient’s age, medical condition, etc., which are provided on the basis of a meal plan issued by a physician as a direct means of disease treatment “(Summary of social insurance medical fee for 1994 (Heisei 6)).

6.2.1 The Problem of the Producer

In other words, hospital meals were incorporated into the medical system, the significance of being part of the treatment was emphasized, and hospital meals were considered to be the same as medicine. If they were the same as medicine, there is a saying that “good medicine is bitter in the mouth,” and it was recognized that hospital meals do not have to be tasty but should be eaten obediently for the sake of treatment, and dietitians and medical personnel neglected efforts to make meals tasty. Moreover, unlike customers in restaurants, hospital patients could not run away.

However, the affluent society that came with high economic growth created a gourmet orientation, and hospital meals were required to be tasty. At that time, the necessity of patient service was emphasized throughout the medical care system. Naturally, there was a demand that hospital meals be made appetizing, and mass media carried articles every day saying that hospital meals should be tasty. In those days, hospital meals were used as a metaphor: “This restaurant is as bad as hospital meals,” so that people could understand how bad the restaurant was. At the time, former Prime Minister Kakuei Tanaka, who was arrested in the Lockheed affair and spent time in prison before being hospitalized for a stroke, commented that hospital meals were worse than prison food. Based on this social background, both the government and hospital officials started full-scale efforts to make hospital meal tasty.

What could we do to make the meals more delicious at St. Marianna University Hospital, where I participated? In the process of implementing the improvement measures, I suddenly thought of a question: “In the first place, are sick people in a condition where they can perceive the taste of food?” When a person is healthy, he or she has an appetite, can perceive the taste of food, and can eat as much as he or she wants. However, when the person becomes ill, these capacities are reduced and the patient is not able to eat well and the sensation caused by food is limited both in quantity and quality.

6.2.2 The Problem of the Eater

We investigated the sensitivity of taste in patients with liver disease. Different concentrations of sweet, salty, sour, and bitter liquids were dabbed on filter paper and placed on the tongue to determine the sensitivity to each taste. In the acute phase of the disease, all patients with liver disease showed a decrease in taste sensitivity. However, as the patients’ condition improved, their taste sensitivity improved and they were able to eat with appetite. When a patient is first admitted to a hospital and feels that “hospital meals are bad,” there is often a problem on the part of the eater.

6.3 Warm Is Warm, Cold Is Cold

Although hospitalized patients have a problem of decreased gustatory function in sensing taste, we thought that we should try to make hospital food more appetizing.

6.3.1 Improving Where Patients Eat

The first question we considered was whether the bed was an appropriate place for eating. In general, hospital rooms have a peculiar odor caused by disinfectant and body odor, and if there is a portable toilet under the bed, it is like eating in a toilet. No matter what kind of high quality food is served in a toilet, it will not taste good. In general, patients eat in bed, but once the acute symptoms have passed and a patient’s condition has stabilized, I thought that the patient should eat in a place appropriate for eating.

In St. Marianna University Hospital, on each floor there was a pantry where meals were prepared. This space was converted to create the first “patient cafeterias” in Japan. The room was decorated in orange, a color that stimulates appetite, and background music was played. We also controlled the temperature to ensure that meals were served hot. The patients were given a choice between the bed and the cafeteria. By improving the food environment in this way, the number of leftover meals decreased and the amount of food consumed increased. Later, this method was approved as an “additional fee for patient cafeteria” in the medical treatment fee because it was useful for recovery from illness, and this method spread nationwide.

In 1987 (Showa 62), “St. Marianna University Yokohama City Seibu Hospital” was established in Yokohama. At the opening of the new hospital, we took on the challenge of creating a model for hospital meals in Japan.

In the new hospital, I was able to create the hospital meal service that I wanted because I started from a completely blank slate in terms of hardware such as the kitchen, office, and patient cafeteria, as well as of software such as the meal service system and computerization. Patient cafeterias were set up on all floors. In order to provide hot meals, heat-insulated wagons were introduced throughout. One wagon costing 2.5 million yen was purchased for each ward (Photo 6.1). At that time, the hospital director said to me, “Nakamura bought 15 expensive Japanese cars” It cost a lot of money to make the food tasty, but in the end the director of the clinic was pleased to hear the high evaluations from his patients.

Photo 6.1
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Temperature control with hot and cold delivery vehicles. (All paper work is computerized (above); The menu is prepared on the train line (bottom left); Hot and cold delivery vehicles (bottom right) deliver to the wards)

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In general, in Europe and the United States, expensive investments are made in the temperature control of meals, but in Japan, hospital management was not enthusiastic about the temperature of meals. This is because, in Japan, the provision of hot meals was carried out to suit patients who wanted to eat their food hot but in Europe and the United States, meal temperature control was treated as a risk management issue to prevent food poisoning.

This is because it is important to prevent food poisoning by keeping staple foods, main dishes and soups warm and side dishes, pickles and fruit cold, and avoiding leaving them at room temperature where bacteria and viruses can multiply. Temperature control is necessary even during cooking operations in the kitchen, and food poisoning will not occur if food is kept at a high or low temperature where bacteria do not multiply for the 1 or 2 h from immediately after the end of cooking until the food is put in the patient’s mouth. In order to prevent the food from being left at room temperature, a heater and a refrigerator are placed along the tray line where the serving work is carried out, and a hot and cold delivery vehicle is used to carry the food to the wards so that the temperature can be controlled without interruption. In fact, I have managed hospital meal service for more than 30 years and have never had a single outbreak of food poisoning.

Controlling the temperature of meals is essential not only to provide a tasty meal, but also to prevent food poisoning. If food poisoning occurs in a hospital, the kitchen will be closed for at least a week, and the name of the hospital director will be reported in the newspaper. Temperature control for hospital meals is an inexpensive investment in security from a crisis management perspective.

6.4 Softening in Front and Hardening in Back for a Pleasant Meal

In Europe and the United States, there was a system where people could choose their own menu for hospital meals. Why couldn’t we do that in our country? I thought that since airplanes offer in-flight meals where you can choose from two kinds of warm food even in a small space at an altitude of thousands of meters, there is nothing that cannot be done in hospitals on the ground. In Western hospitals, when you are admitted to the hospital, you are given a menu list and can choose all the dishes, which is called the restaurant menu system. I first considered introducing this method. However, I realized that it would be too complicated and impossible in Japanese hospitals where patients are hospitalized for more than a month, although it is possible in Western hospitals where hospitalization usually lasts 2 or 3 days. This is because the repetition of one or two menu lists or a weekly menu limits the number of dishes that can be served and patients become bored. In addition, it was nearly impossible to keep the nutritional content of freely selected menus constant.

6.4.1 Introduction of a Selection Menu

What struck me was the selection menu system for in-flight meals on airplanes, where [maybe add ‘only’] the main dish is selected. Even in daily meals, people generally choose what they want to eat, whether they want meat or fish, Western or Japanese food, whether they want rich or light food, etc., from among two types of main dishes. If we were to create two sets of menus with a selection of main dishes, including therapeutic meals, we thought this would be feasible if we used computers, which were becoming common at the time. The more we improved patient services such as offering selective menus, the more complicated the work would become and the more information would be required. However, we thought that we could solve the seemingly contradictory task of improving service and streamlining by actively using computers. Most of the clerical work involved in providing meals, such as the management of meal types, number of meals, and ingredients, the issuing of meal tags, the calculation of orders to vendors, and the preparation of order sheets, was all computerized In other words, the work behind the scenes of providing meals was thoroughly streamlined, and the philosophy of the business was to provide as much detailed human service as possible in direct contact with patients, such as calculating the appropriate amount of nutrition for each patient, collecting information on preferences, complaints and requests from patients, intake capacity, and providing advice. Operations such as clerical work and preparation in the kitchen that do not involve direct contact with patients were thoroughly computerized or robotized, while services on the front that are visible to people were provided with a human touch, and this is described as “softening on in front and hardening in back”.

6.4.2 Computerization of the Hospital Meal System

At that time, in order to build a hospital meal system, we aimed to computerize as much information as possible and robotize kitchen operations. We already had an expert draw up an illustration of an unmanned kitchen (Fig. 6.1). This did not turn out as illustrated, but immediately after the opening of the hospital, visitors poured in daily.

Fig. 6.1
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Unmanned kitchen Created 30 years ago based on “softening in front and hardening in back”

“Documents: The future of hospital nutrition departments, Visual Dictionary of Nutritional Sciences, Salvio, Volume 2: Body and Nutrition, Dailec, pp. 162–163, 1988”

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In Japan, ‘heart’ is used to describe food that is prepared with care and concern for the person who will consume it. Therefore, the Japanese consider a meal that is reasonably prepared by humans to be a poor meal that is not heartfelt. In the first place, heart does not exist in a dish, but the person who eats it tastes it and feels the heart. Therefore, a dish should be made rationally so that the person who eats it can feel the heart, and a first-rate cook does not put his or her heart into each dish, but rather has mastered a technique that allows the person to feel the heart. It is more effective in terms of hygiene control if there are as few people as possible in the kitchen, because there is less chance of contamination by E. coli. At the hospital, I never said “cook with all your heart”, but in the questionnaires I regularly received from patients, they always replied, “Thank you for your heartfelt cooking.” At present, there is a lot of discussion about the professions that will decline and disappear with the advent of AI, but this kind of experience already took place in the era of the introduction of computers.

Referring to our challenge, in 1992 (Heisei 4), the government approved the “additional fee for specially managed meals” in the medical fee schedule for meals served at appropriate temperatures in a timely manner. This meant that warm meals were paid a medical service fee, which was unique in the world. The 1994 amendments included the abolition of the “Standard Meal System” and its replacement by the “Inpatient Meal Treatment System”. In addition, the “additional fee for a special management meal” was renamed [the/an] “additional fee for special management”, and the “additional fee for a patient cafeteria” and “additional fee for a select menu” were newly approved. The “additional fee for special management” is granted when a meal is provided to a patient under the guidance of a dietitian and meets certain conditions, such as being timely and at the right temperature. “Timely” means that dinner is served after 6:00 p.m., and “proper temperature” means that meals are served at a temperature maintained by means of heat-retention/cold-retention, heat-retention trays, heat-retention tableware, and the cafeteria.

The “additional charge for patient cafeteria” means that the hospital has a cafeteria and the floor space meets the condition of 0.5 square meters or more per hospital bed. The “additional charge for select menu” can be calculated when multiple menus that patients can choose from are provided for two main meals a day. Later, when timely provision of appropriate temperature and select menus became common, these add-ons were abolished, and the financial resources were used for clinical nutrition management in wards.

In 1994, the Asian Conference of Nutrition was held in Kuala Lumpur of in Malaysia and a symposium there focused on the computerization of nutrition services. I introduced examples of the computerization of nutrition services based on our own experience, and presented the principle of “software in front and hardware in back”. In other words, interpersonal service for people was humanized, while the behind-the-scenes work was thoroughly streamlined. Therefore, dietitians/nutrition professionals should not be afraid of computers, but we should actively use them to improve the quality of our own work. After the presentation, the audience applauded loudly and asked many questions, and I remember being so moved that I got goose bumps.

At that time, the idea of creating an “Asian Congress of Dietetics: ACD” was floated by the gathered speakers. After a series of meetings, in 1994, First Asian Federation of Dietetic Associations; AFDA was established to develop research in practical nutrition in Asia (Photo 6.2).

Photo 6.2
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Declaration of The First Asian Federation of Dietetic Associations; AFDA at the first Asia Congress of Dietetics in Jakarta in 1994

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The challenge of making safe, tasty, and hospital meals took several years of tireless work, and was unimaginably difficult. At the time, it was introduced as “The Challenge of Hospital Meals” on NHK news, and a video was made. It became a model for hospital food that patients can eat easily and comfortably. We were able to do this because of the understanding and cooperation of Dr. Yukiko Kawashima et al. dietitians in the hospital and MEFOS Co., Ltd a food services.

6.5 Future Hospital Meals and Clinical Nutrition Management

The primary characteristic of medical care in Japan is that it is operated on the basis of the “National Health Insurance System” that began in 1961 (Showa 36). This system allows all Japanese citizens to receive medical treatment on an equal basis, and is financed by insurance premiums, taxes, and co-payments. Conventionally, medical service fees are paid by insurance and taxation by subtracting the patient’s co-payment from the amount of the added fee, which is determined by the public price (one point = 10 yen) for each medical treatment, such as the fee for initial examination, examination, medicine, and guidance. This method is called the “piece-rate payment system” and has the advantage that medical institutions can determine the content of medical treatment without considering the cost. However, this method has also had the problem that it is difficult to control the increase in medical costs because hospitals earn more money if they provide high-cost medical care.

Therefore, a “Comprehensive Flat-Rate Payment System” is currently being implemented in Japan. The flat-rate payment system is a system in which the government sets an average price in advance for classified diagnostic groups, and medical institutions receive a fixed amount regardless of the cost of the procedure. This method makes medical care more cost-conscious and helps to control the total cost of medical care, because if medical care is more expensive than necessary, a deficit will result.

6.5.1 Controlling Medical Costs Through Clinical Nutrition Management

Hospital malnutrition is caused by loss of appetite, taste, digestion, absorption of nutrients, and metabolic changes. Malnutrition decreases the QOL of patients, reduces the therapeutic effect of drugs and surgery, increases the length of hospital stay, and ultimately increases the cost of medical care. At present, the importance of clinical nutrition management using hospital meals, enteral nutrition, intravenous nutrition, etc., has come to be emphasized because it is now understood that improving the nutritional status of injured and sick patients can increase the effectiveness of treatment and reduce medical costs. Clinical nutrition management has been evaluated as a method to bring about cheaper medical care, especially when the “Fixed Payment System” is fully introduced, because the more medical institutions control medical costs, the more income the hospital will have.

In recent years, as patients with chronic diseases have become older, new challenges have arisen in dietary therapy.

First, the elderly have multiple diseases and complex disorders of various tissues and organs. Conventional dietary therapy for specific metabolic disorders is less effective. In other words, because there are multiple chronic diseases that cannot be cured completely, and because each condition is related to the others and exacerbation progresses, it is necessary to determine the priority of treatment and the appropriate amount of energy and nutrients based on a comprehensive understanding of the state of the whole body.

Second, diseases of undernutrition such as emaciation, anemia, sarcopenia, hypoalbuminemia, osteoporosis, and bone fractures are emerging among the elderly with diabetes and kidney disease. Even in the absence of disease, many elderly patients become frail. As they age, their appetite and taste buds decrease, their ability to chew and swallow decreases, and their ability to synthesize and break down nutrients decreases, meaning that they need more time to recover from disease. Diet therapy increases the risk of malnutrition if implemented for a long period of time because it forces people to eat an unbalanced diet compared to the diet of a healthy person.

6.5.2 Hospital Meals and the Way Out

Thus, as diet therapy becomes more diverse and individualized, the operation of hospital meal services is currently in a critical situation. The reasons for this are: ① A shortage of human resources to take charge of meal service operations, ② Meal service management is becoming difficult due to soaring labor costs, meal service material costs, and consumption taxes. ③ Hospital management itself is deteriorating, and ④ The number of people eating meals is decreasing due to a decrease in the number of hospital stays and the promotion of home medical care. Some meal service companies have withdrawn from the hospital meal business and will not accept orders from hospitals.

In the meantime, the following measures should be considered: securing of labor force including foreigners, improvement of the environment for food preparation workers including wages, and rationalization and simplification of operations. As a medium- to long-term plan, the following can be considered.

  1. 1.

    Thorough rationalization of meal service operations

We aim to streamline operations by constructing a food service system that is as rational as possible and by utilizing IT, AI, and robots for administrative and cooking tasks. In recent years, advances in cooking technology have led to research on the rationalization of food service operations, including the introduction of various processed foods and central kitchen systems. In this case, an important issue is how to incorporate the individuality of each patient’s characteristics into the system.

  1. 2.

    Hospital meals and Clinical Nutrition Management

In promoting the rationalization of meal service operations, one thing that must not be forgotten is the response to the clinical diversity and individuality of the target population, which is the primary important characteristic of hospital meals. Specifically, it is a question of the linkage between clinical nutrition management through inpatient nutrition management and NST, which medical institutions have been actively working on in recent years, and hospital meals, which have been operated as a group meal facility. I believe that the key to both of these is the collaboration of dietitians with ward operations.

It is important for dietitians to understand and assess the nutritional status of the patients in the wards, to make a nutritional management plan, to monitor the nutritional status of the patients, and to communicate the information about the patients’ preferences and eating conditions to the office and kitchen in a rational, prompt, and reliable manner so that this can be reflected in the meals. If a patient is left malnourished, recovery from surgery will be poor, the effect of medication will be poor, and nosocomial infections will increase due to lowered immunity, which will reduce the economic efficiency of medical care and increase the risk of medical safety management. Since nutritional management is already included in the basic hospitalization fee and the fee for nutritional guidance is double the previous amount, the assignment of dietitians to wards is now possible from the viewpoint of personnel costs.

Meanwhile, as co-payments for meals increase, patients are complaining more and more about the food and nutritional management. Some hospitals are beginning to receive complaints that patients have starved to death not because of illness but because of poor nutritional management. If dietitians were to spend time with patients, listen to their complaints about food, and deal with these issues, the problems could be solved and services could be improved. In other words, if the rationalization of food service is not based on the premise that a dietitian will be stationed in the ward, it will simply mean cutting corners on food service, and if forced, will cause new problems in safety management.

6.6 Characteristics of Diet Therapy by Disease

The following is a list of typical diseases requiring nutrition and diet therapy and their characteristics.

  1. 1.

    Diabetes

Diabetes is a disease that causes hyperglycemia due to insufficient or decreased action of insulin secreted by the pancreas, and over a long period of time leads to complications such as arteriosclerosis, renal disorders, retinopathy, and neurological symptoms due to abnormal metabolism of carbohydrates and lipids. The basis of dietary therapy is to normalize various metabolisms, mainly carbohydrate metabolism, as much as possible and to prevent complications; therefore, a low energy and low carbohydrate diet is implemented. Since an abnormal increase in postprandial blood glucose increases the risk of cardiovascular mortality, the glycemic index (GI) is used, and the increase in GI can be controlled by consuming soluble dietary fiber, fat, protein, vinegar, and milk and dairy products.

  1. 2.

    Dyslipidemia

Dyslipidemia is a disease in which cholesterol and triacylglycerol in the blood are in an abnormal state, triggering atherosclerosis. Diet therapy involves restriction of energy intake and carbohydrates as well as adjustment of lipid content. When obesity is a complication, improvement of obesity is the first priority. If total serum cholesterol and LDL cholesterol are high, saturated fatty acids should be restricted and polyunsaturated fatty acids should be ingested. However, excessive intake of polyunsaturated fatty acids also lowers HDL cholesterol and makes it susceptible to oxidative reactions, so when HDL cholesterol is low, oil containing a large amount of oleic acid, a monounsaturated fatty acid, should be used. A negative correlation has been observed between the intake of n-3 polyunsaturated fatty acids, which are abundant in fish and shellfish, and mortality from coronary events and myocardial infarction. These oils and fats have been shown to lower triacylglycerol, lower blood pressure, inhibit platelet aggregation, and improve endothelial function.

  1. 3.

    Hyperuricemia, Gout

Hyperuricemia is a disease in which the uric acid concentration in the blood is abnormally high, and gout is a condition in which uric acid crystallizes into urate, which accumulates in the joints and causes acute arthritis. The basic diet therapy controls the production of uric acid; overeating, obesity, high-purine and high-protein diets, and heavy alcohol consumption should be avoided. In order to increase the excretion of uric acid, adequate hydration should be provided. Patients should refrain from eating foods with extremely high purine content.

  1. 4.

    Hypertension

For patients with hypertension complicated by obesity, weight loss should be given priority, and a thoroughly low-sodium diet should be adopted. To reduce salt, use patients should substitute citrus fruits and spices, and use low-sodium foods such as low-sodium soy sauce and miso to make food more palatable. In addition, seafood, soybean products, milk and dairy products, vegetables, fruits, and seaweed should be actively consumed, and protein, dietary fiber, calcium, and calcium should be actively taken.

  1. 5.

    Chronic kidney disease (CKD)

Chronic kidney disease (CKD) is characterized by findings indicative of renal disease, such as positive urine protein, or a decline in renal function that lasts for more than 3 months. Diet therapy depends on the stage of CKD and is based on protein and salt regulation with an adequate energy supply. If obesity is present at any stage, weight loss is used to prevent worsening of CKD, and if hypertension is present, salt should be limited to less than 6 g/day. The stage of renal function decline is diagnosed by the glomerular filtration rate (GFR), and protein intake should be limited according to the stage. In the case of hypercalcemia, intake of potassium should be limited. If protein is severely restricted, it will be difficult to plan menus and prepare food on a daily basis, so low-protein foods for the sick should be utilized and their effect on nutritional status should be considered.

  1. 6.

    Surgery

Surgery is a major invasion of the organism and increases nutritional requirements. In addition, it is necessary to pay attention to the change in nutritional status because the amount of intake decreases due to diseases and disorders. This is especially evident in surgery for digestive diseases. The nutritional status of the patient should be improved before surgery, and depending on the type of disease, appropriate diet therapy and nutritional supplementation are required during and after surgery. The physiological risk increases as the degree of feeding, enteral feeding, and intravenous feeding increases, and it is necessary to try to rely on the oral diet as much as possible (Table 6.1).

Table 6.1 Significance of diet therapy (oral nutrition)
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If oral intake is inadequate, enteral feeds are often added. The method of nutritional supplementation and the amount of nutrition to be administered are determined by monitoring the patient’s body weight, intake, digestion and absorption, and whether or not there is an increase in the amount needed. In general, after surgery, in consideration of the burden on the digestive tract the patient should start with a fasting diet, followed by a liquid diet, a 30% porridge diet, a 50% porridge diet, a full porridge diet, and then a regular diet, and the schedule should be constantly monitored. In order to lighten the burden from any one meal, frequent meals with snacks in between should be considered.