Help! Im thinking of writing a weight loss ebook

Recently, I started an exercise diet plan. It was pretty darn successful. I lost 7 pounds in one week. I suppose I could write an ebook about this. I just don't know where to begin.

I lost the weight naturally just by eating right. I've read a bunch of ebooks where the author appeared to be long winded and really just beat around the bush for a dozens of pages before actually getting to the point. My ebook would be short and to the point. Without it being long winded would that decrease the value?