This fully updated and expanded third edition is a reference guide on nutrition and its clinical implications for health and disease through the life-cycle. The book endeavors to address the needs of those who would most benefit from up-to-date information on recent advances in the field of nutrition. Written by experts in the field, chapters cover a diverse range of nutritional areas that present a succinct overview of recent thinking and discoveries that have the greatest capacity to aid physicians and other healthcare professionals in improving the nutritional health of their clients. The text is divided into eight parts. Part one and two address the nutrient requirements and special nutrition-related issues for people across all stages of the lifespan—from pregnancy and infancy through the adolescent years to the older adult years. Part three summarizes the role of nutrition in the prevention and management of chronic conditions frequently seen in clinical practice, including obesity, diabetes, bone disorders, coronary heart disease, hypertension, and cancer. Part four describes different dietary patterns (the Mediterranean diet, the DASH diet, the vegetarian diet, and the ketogenic diet). Part five describes nutrition challenges specific to surgery and several different acute diseases and disorders (gastrointestinal disorders, food allergy and intolerance, diseases of the liver and pancreas, kidney disease, eating disorders, bariatric surgery, sarcopenia, and drug interactions with food). Part six looks at different aspects of the diet (coffee, tea, dietary fat, dietary sugars, energy drinks, alcohol, dietary fiber, vitamins, minerals, and the gut microbiome). Part seven examines a range of factors that influence dietary health decisions (creating nutritional behavior change, methods for assessing nutritional status, Dietary Reference Intakes, an overview of the diet and food guides, food labels, and sources of nutrients). Finally, part eight looks at dietary supplements (including the problem of dishonest marketing) and false and misleading information in the area of nutrition.  The growing nutritional impact of COVID-19 is discussed throughout the book where appropriate. Nutrition Guide for Physicians and Related Healthcare Professions Third Edition serves as a comprehensive guide that is organized by age/lifespan, nutrition therapy in relation to chronic disease and COVID, diet and its role in prevention, dietary requirements and recommendations, and influencing health decisions for the patient. It is a valuable resource of practical and easy-to-access information on nutrition for physicians, nurses, pharmacists, and others in their daily practice.