- Food we eat
- Skin - for instance processes sunlight and creates vitamin D - You can absorb substances like creams through your skin - Etc
- Breathing - Oxygen of course
- Subtle energies - For instance the love or company of a person might "feed" you in subtle ways - The healing power and freshness of nature might give you energy.
Let's expand a bit on the idea of subtle energies...
We talk about energy body, biofield or etheric body.
All these terms describe the same electro magnetic invisible part of our bodies.
For instance when you practice yoga or build up your Qi through martial arts, it's on your energy body that the impact is the greatest.
You harmonize the flow of energy on that level.
If you practice some EFT tapping technique or see an acupuncturist, it is again on the subtle energy body (meridians are a part of it) that you have an impact.
If you practice breathing techniques, again, you activate your energy body and create a new flow of life force in your system.
Life force, prana, qi... All these are different words for the same invisible energy.
How much of our nourishment do we get from subtle sources?
I think it is REALLY impossible to tell for sure as we don't have ways of scientifically measuring these energy inputs.
So, having rational scientific explanations for all that will come much later.
For now, what I am doing is taking an experiential approach and using my feelings, impressions, instinct and intuition to navigate these experiments.
I am playing with that edge, that very limit to explore with what diet and amount of calorie intake my body, energy levels and performance are the most optimized.