I was very glad to finish with ND, because, although it worked for me, and I was able to do a fair amount of exercise, I never felt optimally well on it.
And in the 3 weeks following ND, I used only 1packet of Optifast divided into 3 for the day, and added fish, cheese and egg and more leafy vegetables to the same 800calorie value,and felt much better.
Now I believe that the Optifast method, while simple to follow, and supposedly balanced for nutritional purposes, may not be as good.for the metabolism as real food, And the percentages, particularly of carbohydrates would be quite different.
Now, I am using LCHF principles and keep the portion sizes within reason, somewhere between 1200 - 1500 calories.
This FF I decided on, only because I will not be able to do my usual activities for some weeks because of an injury, and I fear weight gain as a result.
Since I have been fat fasting, I have been surprised by how little hunger I feel, particularly in the afternoons. So probably, for the next 2 days, I should try for more oil and fat in the forenoon?
Sorry to be so prolix, you are right, it is interesting how individual tolerances vary,