Are they effective?
Yes, you will lose weight on a High Protein/Low Carb diet at first, but 90% of the weight reduction will be water. And that's when the issues start.
After your body has lost its water weight, what occurs next?
It begins by burning any remaining fat, and then, in the absence of carbs to burn for energy, it turns to protein - your muscles.
These diets cause a metabolic state known as ketosis, which is a dangerous condition that affects persons with kidney disease and diabetes. It is uncommon to find it in healthy persons.
Protein is nature's building material and is essential for repairing and rebuilding your body's cells, tissues, and organs, thus burning it is unhealthy.
Proponents of the Low-carb, high-protein, high-fat diets downplay ketosis, claiming it's indication that your body is burning fat. In part, this is correct. Ketosis not only burns fat, but it also burns muscle tissue over time.