Nutritional intervention methods in the experimental group
fists
In the food exchange method, the daily food intake required by the patient is measured according to the ‘food exchange portion’ of cooked food rather than the traditional raw weight (in grammes), with the portions formulated by the nutritionist. Here, the different parts and shapes (actions) of the hand serve as the estimator of the food exchange portion, which corresponds to the cooked food volume of various foods and includes a clenched fist, a half-clenched fist and the palm. The tableware used included one ceramic spoon (measures the vegetable oil), one 4-inch rice bowl (320 ml) (measures the staple food), and one salt control spoon (2 g). The patients were then given simple measurement instructions, which included one fist (one hand) of fruit, two fists (two half fists) of vegetables, three spoons of vegetable oil, four fists of staple food, five palms of fish (or five small fish) International) protein, and six fists of water (about 1500 ml water) per day.A dietary intervention group was then established, which included full-time nutritionists, competent doctors and cardiac rehabilitation nurses to formulate individualised nutritional prescriptions according to the patient's condition, body composition analysis data and 6MWT distance, as well as their activity intensity and daily nutrition intake following discharge. The total calories and the ratio of the three major nutrients were then recorded, with the daily caloric energy supply set at 20–30 kcal/kg according to the daily activity of the individual, of which protein accounted for 10%–14% of the total energy at 1.2–1.5 g/kg per day [The nutritionist then had a one-to-one consultation with the patients in hospital face to face or through web software like wechat to discuss the nutrition prescription of the food exchange intervention, including in terms of the daily food intake of cereals, potatoes, proteins, vegetables, nuts, fruits, oils and fats, as well as how the six categories of food are allocated to three meals, and how the food items are interchanged.The nutritionists then guided the patient in how to use their hands as a food exchange portion estimator, demonstrating the different postures and parts of the hand that correspond to various food exchange portions. Foods of the same type are interchangeable, while foods of different types are not. Each patient was asked to practice measuring the volume of different foods of the same caloric value until they mastered the required number of food exchanges and could measure the food exchange portions proficiently.