You can simply use the example of how a company is run during good times (plenty of foods) and bad times (reduced caloric intake / fasting).
A company in good times will often look outwards – expanding and finding new sources of growth. The same is true for our body. When we have plenty of foods (hence plenty of nutrients), our body only concerns itself with how to extract nutrients the best it can. Have you ever heard of a company with plenty to spend downsize in the best of times?
Our body improves through "downsizing"
A company in bad times works completely differently. It will look inwards to “fix” – selling out toxic assets, cutting off units that are loss-making, and finding out where the inefficiencies and redundancies that are dragging down the company. Our body does exactly the same – in times of constraints, survival instincts kick in and we get rid of what’s dragging us down. This is what fasting is.
Fasting is a lower-than-usual food intake for a sustained period. It “forces” the body to switch gear, from its “lavish” operating mode to a “frugal”, self-improvement hunt.
You may pause and think about why that mode switching is crucial. matters. Say stored belly fat, when your body has access to plenty of foods, it is not incentivized to go after and burn your belly fat, despite how hard you try or how healthy you eat.
Old cells VS New cells determines how healthy you are
Inefficiencies are less obvious to most of us. Your body is made up of many cells and these cells are what determines your health. Some of them have been around for longer, they are older, less healthy and less efficient. In good times, your body will still make new, younger cells but also leave the older cells intact. But think about the earlier analogy of a company - a loss-making unit is still going to cost and drag down the whole company, no matter how many other new, better-performing units are built.
When you fast, without enough “fuel”, you are putting “pressure” on your body to make a selection – to keep either the old or the new, but not both. Your body is smart, in fact smarter than you may think. Besides making the right selection, it will even recycle what is still useful in the old cells into making younger, more efficient cells - converting old cells into fuel and feeding the new cells.
This ability of “self-improvement” has always resided in your body. Fasting did not arm your body with something it does not already know. But in the best of times, our body will always choose an easier path. What fasting provides instead is a “stress” signal. That in stressful situations one improves sounds familiar to you?
Isn’t what our body does impressive? What was highlighted was essentially the process of “autophagy”. This important discovery and how it works was awarded the 2016 Nobel Prize.