Ideal in this case doesn’t mean a preferred weight or a weight goal. In drug dosing and nutrition, we use an ideal weight that basically discounts weight that isn’t really contributing significantly to metabolism. The same kind of estimate is also used to estimate kidney function.

Quick clarification of some terminology: “Ideal Body Weight” doesn’t refer to your preferred weight. It’s a defined measure. For men, Ideal Body Weight is 50 kg + (2.3 kg x (height in inches-60). For women, 50 kg + (2.3 kg x (height in inches-60). So for your hypothetical 5'10'’ man, his ideal body weight would be 73…