If we had a valid quantitative measure of health, we could answer this question with some ingenious experiments. Lifespan is too medically manipulated to be a useful measure of health anymore.
The term “biocalories” refers to “corrected” calories. For example, the calories of fiber do not count because they are not digestible by us. The calories of the protein used in repair (about 50 grams a day for the average person) should not be counted as dietary calories. The calories that are excreted should not count as dietary calories. Etc. The result is a simplified equation: Biocalories (input) = biocalories (burned) + biocalories (stored). For a more extensive treatment, see my book Maximum Irony.
The term “diet format” refers to the manner in which feeding and fasting occur. The “Fast 5” (Bert Herring) is a diet format in which feeding occurs for 5 hours and fasting for 19 hours.
The term “nutrients” refers to everything important to health, including things we take for granted such as water and oxygen intake. And not just “essential” nutrients, of which there are about 45 known at present (more await discovery), but all of their cofactors, and all of their cofactors, etc. Picture “n” coordination “spheres” in a vast network. In this network, what is bound to an enzyme or a structural protein? Its cofactors inside the enzyme or protein and layers and layers of other macromolecules outside the enzyme or protein, each with their internal cofactors. What binds to the internal cofactors? Their external cofactors, including V3 nutrients. Eventually, solvent is all that is “out there.” But even this solvent may be quite structured in particular environments, thus adding significance to whatever is “out there” helping to maintain the structure. Those molecules helping to structure the solvents (aqueous, semi-aqueous, and non-aqueous) are also “vital” or important V3 nutrients.
A process sure to lead to the discovery of new essential nutrients is autophagy. Disorders are so common in autophagy that I must believe there are nutrients essential to running it and regulating it that have yet to be discovered.