I start from the privilege that eating instinctively means eating healthily. I strongly believe that the body can transmit to the brain accurate information about its nutritional necessities: a moderate amount of food, and only foods that are beneficial for health.
Most of these natural eating instincts, alas, are lost on the way. Usually, during the growing process, adults project their unhealthy habits on children, offering them a range of foods that are not always the best choices. As adults, we form our own eating habits, which are more or less healthy. We usually worry about our children's eating habits, but their instinct is often correct.
My theory has as starting point my own experience as a child, when I recall rejecting foods that I found too greasy or too deeply fried. Observing the behavior of babies and children towards feeding might give us an idea about what eating instinctively means. Small children who did not have the time to be influenced by adults, have their natural eating instincts unspoiled. Contrary to adults' opinion about eating, they want to eat many smaller meals and only when they are hungry.
To support my thesis, I resort to the recommendation made by specialists in baby nutrition. They advise on feeding babies on request, not forcing a program on them. Thus a meal program will be generated by their inner scheduler according to their needs.
So, from children we learn that one should eat when hungry, and the amount strictly required by body necessities. We should not be driven by social cues such as eating out with friends, even if we are not hungry, or take a lunch break just because it is 12 noon.
Another reason which supports the theory of a simpler way of eating is that based on foods offered by nature. All living creatures find in nature what they need to sustain life. Theoretically, foods of natural origin in their unspoiled state should be sufficient to ensure a healthy existence. While I do not support any kind of paleolithic diet, but we are bound to make reference to the simple way of eating in ancient times. In modern times modern and more complex diseases have developed. These include the increased incidence of tooth decay, allergies and various diseases of the digestive system such as diverticulitis, most of them closely connected to modern diets. Man was not built for so many refined and super-refined processed foods. Cooking, the great discovery, was just a means to make foods more digestible. Nowadays we experience an extreme version of modern eating, one abounding in processed foods and pre-prepared meals.
Eating raw foods, such as vegetables and fruit, in proportion to cooked meals is definitely unhealthy. It is also healthy to choose unrefined foods, as natural as possible.
We need to reconsider our diets and healthier ways of eating. But it is harder to re-educate ourselves and easier to acquire good habits from scratch. First we need to forget everything we know, get rid of all unhealthy habits and only then rediscover eating. And it is even harder to resist the many temptations scattered around us.