Why is having too much fat or too little fat a potentially serious health problem

There are many reasons but one is,

Being too fat is a problem because if you eat too much, certain types of fat can cause a diet rich in saturated fat which can make cholesterol levels in blood. That can increase risk for heart disease.

Having too little fat is a problem because you could have mood problems, heart problems, Excessive appetite and eating too many vitamins causing more health problems

this is true my friend.        

steady state because it the only on that maes sense