Explain the History of Nutrition?

Knowledge of human nutritional needs and relationship between diet and health was placed on a modern scientific footing only since the 19th century, after Lavosier established that the body obtained energy through oxidation of foodstuffs and Magendie recognized that protein was essential in the diet for survival. Respiration chambers for estimating energy requirements were developed by mid 19th century. Nitrogen balance studies that measured nitrogen retention reasonably accurately made it possible for the first time to estimate energy and protein requirements with some precision. The first dietary standards were proposed, based on these experiments, in the year 1860 that an adult human required a daily intake of food to provide 3000 kilocalories and 80 g of protein. During the next 50 years, several recommendations were made for energy and protein requirements, most of them based on the usual intakes of healthy individuals.