A change in attitude is common with puberty. Her body is raging with hormone changes and kids don't have the skills to deal with the change. It's similar to PMS. Adult women have difficulty managing their feelings during PMS.
The way I cope with my teen granddaughter who lives with me, is to ignore the attitude by not responding to it. If she has a question or is asking for something I can provide, If it's possible considering her attitude,.I respond to the question or need while not responding to the attitude. Often, I just walk away. At the beginning, when all was calm, I told her I would walk away because I didn't want to fight. That I saw her attempt to talk as a challenge to fight.
I've learned with my daughter, her mom, that I don't have to control her attitude. She knows she's out of line. Her consequence for the bad attitude is my leaving her. Discipline unrelated to her attitude makes her mad and lesson is lost.
I think taking her to her doctor is important not only for medical evaluation but for information about what is happening to her. It's especially important to talk with the doctor about her diet and how to get her started in healthy ways to lose weight.
BTW I've read that this stage is similar to bipolar symptoms. Teens aren't bipolar. They just act like they are.
Also, at 10, she will likely thin down as she grows taller. The extra weight now is her body's preparation for growth. When we starve ourselves our body holds on to the fat because it thinks our body needs it to survive.