Well might as well make my first post for a subject that I have researched recently.

It is not so much "programming" as your current metabolism. You can change that and it does not necessarily take six months...but it could. It depends upon your calorie intake and what calories you expend by exercising and your amount of lean body mass.

With respect to nutrition, calorie intake should not be dropped below basal metabolic rate (google it for definition) otherwise body goes into starvation mode which may have led to the "programmed" concept to be mentioned since most diets make you restrict calories.

For calorie expenditure, walking can be sufficient...at first...for severely obese people. Lifters can make do with just the calories from lifting. However, they may need to add cardio to provide the necessary calorie deficit. Extended cardio sessions can rob muscle tissue which works against trying to increase metabolism. Shorted sessions seem to be better and muscle tissue can be preserved as long as diet is good.

So, the key is good nutrition with lots of exercise. To preserve muscle mass, the diet should consist of sufficient calories with higher protein levels. Better results come from eating even more and exercising a lot more. Difficult to do and then you have to be careful about overtraining depending upon what your selected exercise is. Better to expend calories with all sorts of different types of exercise which decreases chances of overtraining.

A lot of what I learned came from Tom Venuto's Burn the Fat, Feed the Muscle eBook as well as a variety of other sources. I only read about this stuff and am not by any means a professional but I think I got most of the concepts right.