Does being dehydrated affect lung capacity?

Not direclty: Being dehydrated would not affect lung capacity in terms of spirometric testing, however,it will cause weakness similar to that due to limitation of lung capacity. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, low fat milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex.