Correction of underweight and overweight by exercise by C. O. Benson is a practical health and fitness guide written in the early 20th century. It outlines how to manage body weight through exercise, supported by diet and sensible daily habits. The book opens by warning of the health risks of excess weight and identifies common causes such as sedentary living and overeating, with brief mention of glandular issues. It rejects “reducing drugs,” urging medical examination, a structured diet, persistence, and regular exercise instead. Benson gives clear food guidance (avoid concentrated fats, sugars, and starches; prefer bulky vegetables, lean meats, and regular meals; no snacking, especially candy) and hygiene routines (daily bowel movement, baths, and brisk walking). A detailed weeklong calisthenics schedule follows, plus a set of general exercises to burn fat safely. The second part addresses underweight, distinguishing normal from pathological cases, listing causes (poor habits, digestive issues, worry, late hours), and recommending rest, nourishing diets (milk and vegetables), fresh air, sun baths, massage, light exercise without fatigue, and good posture. It concludes with special, gentle exercises designed to stimulate appetite, improve circulation, and support gradual, healthy weight gain. (This is an automatically generated summary.)