[sidlls]

How is it not normal? His regimen apparently consisted of eating fewer calories than he expended by exercise and exercising for 3-4 hours a week, and as a result cut approximately 1.25kg per week for 6 months. That's definitely a bit high (for reference, "rapid weight loss" is generally considered to be losing more than 1kg per week), but it's not outlandish.

The weight loss by itself, with no additional work for the physique, shouldn't take more than about 8-9 months (at a loss of ~0.8kg / week, well within the bounds of gradual weight loss). It shouldn't take 27-39 months beyond that to build lean muscle and lose fat to reduce that level of body fat percentage.

One wouldn't even need to follow the fad diets or take the supplements this guy did.