The very first sustainable weight loss diet was started in 1862 by William Banting, who after being on a search for around 30 years to lose his excess weight, lost 46 lbs (21 kgs) in 12 months, (50 lbs / 23 kgs) in a little over 12 months), William was only 5 foot, 5 inches tall, (165cm).
One of the best pages in William's third edition of his book is his 12 month weight loss timeline, it helped me so much, to the point that I found a new weight loss term (target) inside it, Banting Balance, once you find Banting Balance it's so simple to sustain, see two images of William's weight loss timeline below.
This page above became this page below, now called Banting Balance.
(Banting Balance is simply 3-5 lbs (1.5-2.5 kgs) consistent monthly weight loss)
William's weight loss was once and forever weight loss, along with William's increased lean protein, his diet still included daily servings of bread, fruit/veg, and red wine, he simply found weight loss balance, Banting Balance.
Here's part of two letters William wrote, responding to Americans in the 1870's, this second comment proves William's weight loss was sustained long term, William wrote it in 1872, 10 years after starting his new diet.
Clarifying William Banting's Profession
In William's own words, he was "Cabinetmaker, Upholsterer, and Decorator to the (British) Royal Family".
William Banting had already retired from professional life by the time he lost his excess weight at the age of 65, but much has been spoken about his profession being an undertaker. If you do a William Banting google search, it's the first thing it says about William on Wikipedia, this is incorrect, as William points out in the complete fourth edition of his Letter on Corpulence book, published in 1869.
Four years earlier, in 1865, German medical professor Felix von Niemeyer did a Banting presentation to a king in one part of Germany, William included Professor Niemeyer's speech in the fourth edition of his book, correcting a few of the Professor's comments throughout it, see this below passage, William clarifies his profession in the final paragraph.