I have been on something similar to S_D for about 20 years.  I lost about 10 lbs the first year then have lost less than 1 lb per year since.    My weight is running between 25 and 30 lbs below the starting weight. My weight would probably drop more if I did not have a few meals with more carbs.  Once a week I will have a hamburger with a bun or pizza. It has been good for me wish I had tried it much earlier in my life