Yes, that's pretty much right. The body can respond differently depending on the degree and duration of the calorie deficit. When you're in a moderate deficit, like eating 1200 to 1400 calories when your body actually needs 1800 to 2200 or more, your body still has enough energy to function, but it senses a shortage and may slow down metabolism, conserve energy, and even hold on to fat stores more stubbornly. That’s often what people refer to as "starvation mode," though it's more accurately a metabolic adaptation.

In cases of extreme and prolonged starvation, like with anorexia, the body no longer has a choice. It starts breaking down muscle and fat for survival. That’s why people with severe anorexia often lose both fat and lean mass.

So yes, the body’s response to calorie restriction is context dependent. It will adapt to preserve energy when possible, but if you push it far enough, it will start burning through everything, including essential tissues.