There is no one straightforward formula for weight loss success.
Just because someone you know lost the weight on a particular weight loss diet plan, doesn't mean it will work for you.
Even if you yourself lost the weight on a particular weight loss program at one point in your life, doesn't mean you'll be able to do it that way again. You might be in a totally different place now - you might be in different life circumstances, or emotional circumstances, whatever.
It's really important to think about who you are, what you need, what your likes and dislikes are, where you are in your life at the time. If you want to succeed don't rush in. Take time to consider, think, evaluate, talk to yourself, look around, open your mind.
There simply is no one straightforward formula for weight loss success.