Losing weight fast has its own consequences. The ideal way to lose fat is to cut 500 calories from maintenance calories for a month then drop the 500 cut to 200 cut from maintenance and then eventually eat maintenance calorie and burn more fat with workouts. Increase your activity level gradually.
Prefer reading here is a link to the blog post:
http://manorinfinity.com/blog/why-you-should-never-lose-weight-fast/
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