I would agree, in most cases, pure fat loss takes time and a long time, as it is physiologically impossible, to loss fat quickly. Tapping the energy in one pound of fat equals 3500 calories, which equates to walking 30-35 miles for your average person. Any weight loss, of more than a pound or two a week, is going to involve water weight and since the majority of our body weight is in fluid, it is quite easy to lose weight quickly, it just won't include losing much fat.
I gave the examples I did for a reason, because how someone loses fat, depends on their lifestyle and the stresses they place on their body. I often hear fat loss is mostly diet, when it isn't true for all people. If one has a vigorous exercise regime, they will have all of the physiological benefits I mentioned in my last post and this will encourage and promote the burning of fat, regardless of the diet.
I have always said and this has rung true in my personal experience and in my studies at a graduate level in physiology; the more sedentary a person is, the more important their diet becomes, the more active a person becomes, the less important their diet becomes.
I am not saying diet does not matter in a person with a vigorous exercise regime, because it does in regards to getting enough protein to rebuild muscles and to get the fuel to perform the exercise, but it matters less so, in regards to being able to burn fat.