Discussion: I prefer to eat meat over fish 'because its digestion is prolonged and therefore less fattening for the same calories.

The logic you present is the opposite of that of the human body. The easier the food is to digest, the better it is absorbed and causes less fattening for the same calories. The explanation stems from the better routing of nutrients for tissue building rather than available energy.

Link: Why do many weight loss diets fail in the long run?
https://www.sf-healing.com/page/214 (Copy & Paste)