Complications and Consequences of Morbid Obesity include:

diabetes or high blood sugar
hypertension or increased blood pressure
high blood cholesterol and triglycerides
heart disease such as coronary artery disease, heart attacks and heart failure
strokes
increased cancer rate (breast, uterine, colon, etc.)
pulmonary disease (lung or breathing diseases such as sleep apnea and pulmonary insufficiency)
arthritis (pain and inflammation in the joints)
infertility or inability to conceive children
phlebitis, deep vein thrombosis (clots), venous ulcers, and  venous insufficiency
increased rate of injuries and accidents
premature and sudden death

Social Limitations and discrimination

Employment Limitations and discrimination

Psychological consequence

Therefore long term weight loss is an essential component for good health.
If dieting is not successful in a patient with morbid obesity then surgery should be considered.