It is obvious that, in spite of all technological, social and cultural development of the human civilization, we are still animals, made of flesh and bones, and those are the things that make us go through the life. Therefore, the body must be taken care of, both mentally and physiologically. While mental aspect is sometimes something out of the reach, physical state of the organism can be maintained easier.
As living beings, we have to eat and provide energy to the body for a normal functioning. This is where the first problem begins. People eat too much and they eat unhealthily. Both of these things are dangerous for the organism, though not immediately, but first signs of some future problem start to show after a year or two. Benign in the begin, these symptoms might be the precursors of some serious medical conditions later on, after a decade or two. Hand in hand with this problem goes physical passivity. Muscles, bones, joints, tendons, ligaments, these all should be active from time to time. If that is not present, well, there will be more problems for the already tortured organism.
Do not exaggerate! You can eat more or less anything you like, as long as most of the food intake is healthy. So, do not eat the entire chocolate, eat one bar! That will not create any problem for the organism and the desire for something sweet will also be satisfied. Yes, it will be hard to cut down the amount of chocolate from too much to too little, but that has to be done. No excuses!
Also, a human organism has to be active, although nothing strenuous is needed. Daily, a walk from job to home, one set of push-ups and crunches might be enough for keeping the basal metabolism at a bit faster rate than usual. That will, hopefully, turn on the fat burning process and make the body fit and strong. Of course, this is a long method, but with increasing the exercising time and intensity of training session, everything will happen much, much faster. So, there is an answer to what is truly natural - only what is normal and moderate.