Doctor said bilateral peripheral edema is caused by my obesity?should i get another opinion?recently had umbilical hernia surgery haven't been active.

Obesity can put a: strain on peripheral vasculature and also on right heart pressures both of which can lead to peripheral edema. Certainly recent surgery would also raise suspicion for additional diagnoses including blood clots and cardiac issues. Your doctor is probably correct since he/she knows you but it's never a bad idea to get a second opinion if you have doubts.

Obesity-->edema.: Because of the increase in intra-abdominal pressure due to obesity, venous return of blood from the legs to the heart is impaired, leading to fluid accumulation in the legs. Granted other things could cause this edema, but obesity is one possible cause. Losing weight will obviously help.