[xienze]

> and often the body's response to calorie restriction is to reduce the amount of energy used.

Presumably the point at which it's VERY difficult to expend more calories than you're consuming is something of an equilibrium point, or healthy weight. I find it hard to believe that if you're still 100 pounds overweight after having lost say 20 pounds that it's nigh-impossible to find more "fat to trim" in the caloric intake, for example.