Excessive obesity is a shackle for the body, preventing it from moving, rising and managing itself; it compresses the vessels, narrowing them so that the place where the pneuma spreads is closed, and it often fades away. The breath of air does not reach the vessels, and in such people the nature of the pneuma deteriorates and they must fear that the blood will also rush into a narrow place, and often their vessels suddenly burst, and this kills. Under such circumstances and in the time preceding this, they experience shortness of breath and interruptions, and should then correct the matter by bloodletting, such people are generally susceptible to sudden death. Generally speaking, death comes more quickly to those who are plump and have advanced obesity, especially to those who gained weight at the beginning of life, because their blood vessels are thin and compressed. Such people are subject to sickness, paralysis, interruptions, diarrhea from the humidity of nature, respiratory disorders, fainting and malignant fevers; they cannot tolerate either hunger or thirst due to the narrowness of the passages for the pneuma, the extreme coldness of nature, the scarcity of blood and the abundance of mucus.
A person does not reach a high degree of obesity if his nature is not cold, and therefore fat people do not give birth to children and do not produce offspring, and their semen is meager. Obese women also do not conceive, and if they do conceive, they miscarry; their passion is also weak.
When all such people are treated with medicines, the medicines barely pass through their vessels to the diseased organs, and if they fall ill, they do not soon feel the disease, because their sensitivity is weak. It is difficult to bleed them, and to cause relaxation is dangerous, because relaxation often sets the juices in motion and they cannot pass back into the vessels, since the vessels are compressed, and this sometimes kills the patient. If they do anything, it weakens them, because their innate warmth is weak, since its place of residence is cramped. We have already said that the best obesity is average, especially in youth, moderate obesity, although it exhausts and makes a person weak for movement, still portends a long life, since it is accompanied by signs of moisture in nature.