> What actually works is a permanent lifestyle change
Surely you can link to a study where a permanent lifestyle change results in permanent weight loss in, say, 25% or more of participants.
The "study" is looking at any number of humans on the planet who permanently maintain a diet of healthy food and reasonable portions, along with a regular exercise program. There is no "yo-yo" effect, because the change is permanent, and the human body responds to that. This isn't rocket science, and there's no mystery to solve as to what it takes to maintain a healthy body.
Also, you will find that the group who has maintained that lifestyle all of their life does not even know what a "diet" is, because the concept of weight loss does not apply.
From athletes to yogis and everything in between, there are plenty of examples of the benefits and results of a permanently healthy lifestyle.