Don't try to become something you cannot. That said, I don't want to discourage you from being everything you want to be, or kill your spirit to succeed. Just be realistic.
The formula "energy plus metabolism equals output" means that all three react synergistically. High output is always desired, so in order to affect output, more energy either has to come in, or metabolism has to speed up, or both. Metabolism tends to be the limiter in most cases, since we can choose how much to eat. The volume of output can also be manipulated through programming.
How do we affect our metabolism to achieve our goals? The most logical means to improve metabolism is to do more work. That may mean more intensity in the same amount of time as before, or it may mean more time, and possibly more time and intensity. Adding more output to the equation immediately puts pressure on the body to make the equation balance.
Many times a rider's metabolism has been stifled genetically and environmentally for many years and is stubborn to move. The way to jolt it into action is not through starvation, which is often a knee-jerk response to the problem. Steady and consistent eating habits will be supported by good and steady energy inputs and high-energy outputs.
It makes sense that we need to increase our output and eat sensibly and consistently in order to change long-term trends. Remember, this is a gradual process, so a commitment to the equation is necessary.
Five small meals per day that yield X number of calories will prod the metabolism with healthy consistent messages, whereas one huge meal of the same number of calories per day would cause it to likely horde whatever calories were coming in rather than put it to work for you. The metabolism is usually a logical and reasonable manager.
Gain Your Metabolism's Trust
If the genetics are trending towards a slow metabolic rate anyway, and then that is followed by years of bad eating and/or exercise habits, the metabolism may hold a grudge that can only be broken with long-term trust and consistency. Patience and discipline are the two primary tenets of the repair mechanism.
"Dieting" and short-term crash-weight-loss programs simply break the trust causing further damage to the metabolic relationship. Dietary and exercise habits need to be correct and consistent and long-term. If you want consistently good output, then the input has to be good also.
Almost all of us can improve what we're doing at some part of this equation. Grade yourself honestly. Is your metabolism happy and trusting? Is there enough energy? Is there enough exercise? Too much? Is your metabolism chapped at having been starved and stuffed with bad food and bad habits? Is there enough energy coming in and where is it going? Where can you improve?
Energy, metabolism and output, along with the central nervous system, are the whole package. Do the math, and it will add up to better performance.