This book is a practical life book to help readers master the knowledge of food science, learn how to design three meals a day, what to eat, how to cook and how to eat healthily. On the basis of briefly expounding people's nutritional needs, the nutritional value of various commonly used foods with energy balance, and the principles and methods of compiling recipes, 270 groups of recipes for three meals a day and the preparation methods of nearly 100 dishes made by various cooking methods are emphatically introduced. Its content is substantial, easy to understand, practical and easy to read and use. It is a good helper for family cooking and daily healthy eating, and can also be used as a reference for catering staff.