Let's take a closer look at the machinery behind this "energy-saving" constitution. Your body carries a specific variant of the FTO gene that is linked to metabolic efficiency. Because of this gene's activity, your body extracts more energy from the same meal than most people's bodies do. Think of it as driving a very fuel-efficient car—you can travel a long way on a small tank.
From an evolutionary standpoint, this trait was an extraordinary survival strategy. In an era when food supply was unreliable, the ability to sustain activity on minimal intake was literally "the power to be the last one standing." In our modern environment of abundant food, the key is redirecting where this efficiency is applied. Your instinct for calculating "return on investment" extends beyond food—it operates on time, money, and relationships as well. This is a cognitive tendency nurtured by your energy-saving metabolism.
There is also a scientific mechanism behind your "cautiousness." In psychology, it is called "loss aversion"—the principle that humans react more strongly to losing something than to gaining the same amount. In your case, loss aversion runs somewhat stronger than average. This is why your risk assessments are precise and your worst-case preparations are thorough. It is not pessimism; it is a rational judgment circuit refined by evolution.