Recipe preparation steps are as follows:

1. Determine the nutritional needs of the diner: This includes understanding the diner's energy needs, the three major nutrient needs, and the specific values of various nutrients, such as carbohydrates, proteins, fats, dietary fibers, vitamins and minerals. These values can be determined by calculating or referring to authoritative nutrient reference intakes.

2. Calculate the calorie and nutrient content of each food: Calculate the calorie and nutrient content of each food according to the nutritional requirements of the diner, following the food composition list or food label.

3. Determine food types and portion sizes: Determine the food types and portion sizes to be consumed based on the nutritional needs of the diner and the calorie and nutrient content of the food. This requires consideration of the mix between foods and the balance of nutrients.

4. Formulate daily recipes: According to the eating habits and preferences of the diner, formulate recipes for breakfast, lunch and dinner to ensure a wide variety of food and balanced nutrition.

5. Adjustment and optimization of recipes: After making the initial recipes, the recipes need to be further adjusted and optimized to ensure that the recipes are in line with the tastes and eating habits of the diners, while ensuring balanced nutrition.

Role of preparing recipes:

1, to ensure balanced nutrition: the preparation of recipes needs to be based on the nutritional needs of the diner and the calorie and nutrient content of the food to determine the food can ensure that a variety of nutrients in the food to get a balanced intake of nutrients, to meet the nutritional needs of the diner.

2. Convenient management of family meals: Recipes can be used as the basis for family meal planning, helping families to manage family meals in a planned manner. Preparing food according to recipes can avoid food waste and repeated purchases, and improve the efficiency of family meal management.

3. Promote health: Reasonable recipes can meet the body's needs for various nutrients, help prevent malnutrition and various diseases, and promote good health.