"Food in War Time" by Graham Lusk is a scientific publication written during the early 20th century, specifically around the time of World War I. This book focuses on the principles of nutrition and dietary practices amid the challenges of wartime food scarcity. It discusses how to maintain a balanced diet with limited resources, emphasizing the importance of caloric intake and food substitutions. The book is divided into three main sections, starting with a discussion of a balanced diet and the role of various food groups in providing necessary nutrients. Lusk explains the necessity of vitamins and minerals, highlighting the importance of foods like corn and olive oil as budget-friendly sources of nutrition. The second section delves into the science of calories, outlining how to measure and utilize energy from food effectively. Finally, Lusk provides practical rules for food saving and safety, urging readers to adapt their diets during wartime for both personal well-being and broader societal benefit. The text is rich with examples and historical context, making a compelling case for strategic food consumption and conservation in times of crisis. (This is an automatically generated summary.)