Nutrition is the selection and ingestion of foods to be assimilated by the body. A healthy diet can avoid many health issues. In 1747, Dr. James Lind performed the first scientific nutrition experiment, discovering that sailors given limes were cured of scurvy where others given other substances were not, though he did not know it was due to vitamin C. Various essential nutrients like vitamins, minerals, amino acids, and fats have been discovered and their roles in the body's processes have been elucidated from the 1930s to present.