Weight loss, especially with "shakes" will happen much slower. Weight loss, or health in general, is all about balance. You shouldn't be just ingesting two shakes and a meal per day. Your metabolism will never speed up with that kind of routine. You should be eating as many as 6 meals per day, in smaller portions. Snack on healthy foods, and eating balanced healthy meals. My metabolism was destroyed after having my son, and only until I learned how to treat my body I'm pretty damn close to where I want to be.
You'd need a balance of multiple meals. Because you're ingesting so few calories and such little food, your body burns everything you eat as energy, and anything left over gets stored as fat in order to get your body to the next meal. Starving yourself is not the answer, I promise. Pack your lunches/meals every day. I work 8 hour shifts and I bring at least 4 items with me for my shift. Exercise is only about 30% of weight loss, everything else is literally what you put into your body. I also carry around a big jug of water, and sip it throughout the day. Water helps fill up any empty space in your stomach and helps keep you full between meals.
Exercise is important of course. I work out 6 days per week, but it's really not necessary. Anything around 3 days per week is pretty good. As much as women are afraid of lifting weights. Lifting weights actually burn more calories per session and speeds up your metabolism better than any cardio. Cardio is still important, but it shouldn't be all you do.
