Is what I’m doing unhealthy?

I’m overweight. I’m 5ft 4in and about 205lbs. I carry my weight well, I’m very well proportioned so my mom and husband think my dieting that I started a week ago is extreme and unhealthy.

I have 2-3 shakes a day (200 cal each) and one bowl of soup (160 cal). So typically I’m at 600-700 calories a day and I’m working out for about 45 minutes every other day.

I only plan to do this for about 6 weeks. Then I will slowly introduce healthy meals and keep my calorie count for the day at about 1,200 or less and work out more rigorously. What I’m doing now is just to detox and get myself off the horrible food I was eating because I was using food for comfort.

Because I am very overweight, I don’t see the harm in being aggressive with the weight loss. I DO need to lose weight in order to be healthier. It’s not like I’m already underweight. So, my question is, do you think what I’m doing is ok? So far in a week I’ve lost 5 pounds and I’d say most of that was just water weight from lowering my sodium intake significantly.