There are many ways to lose weight, but it depends what your goals are. - Do you want the weight loss to be sustainable (in other words, not gain the weight back again)?
- Do you want to lose weight in ways that are not potentially dangerous or harmful?
Hopefully, you said "yes" to both questions above, and if so, the most effective way to lose weight in a healthy, sustainable and quick manner is to engage in the right types of physical activity and exercise daily, as well as lower the amount of calories you eat daily (assuming you are consuming more calories than you are burning).
Healthy, sustained weight loss can be "quick"...but your version of "fastest" may be losing 50 pounds in 50 days, which is not possible (if it were, we would not be bombarded with hundreds of ads a day claiming that we can "lose weight fast!", because we all would have lost the weight by now!). A reachable goal is 1-2 pounds per week for weight loss. Sure...some women can lose more weight than this, but also gain the weight back (plus some!) because they are unable to sustain their normal life with enough energy on a "starvation-type" diet.
If you need to lose 50 pounds, your best bet is to talk with a Registered Dietitian (R.D.) who can calculate your current caloric needs, based on the amount of weight you would like to lose. You can work with this professional on eating plans that you can stick with, and can help track your progress with someone. There are many weight loss programs that are very successful (Weight Watchers, for example), as there are other people going through the same struggles, and leaders help keep you accountable to your goals.
The second part of the equation is increasing your physical activity on a daily basis, and a Personal Trainer can help set goals for your exercise routines and provide guidance on increasing the amount of calories you burn each day. We can provide some resources if you are interested as well!