A healthy diet is one which contains a low amount of animal products and highly processed foods along with a good amount of fiber. In recent years we have become aware of the effects of highly processed foods in our gut microbiome and how chronic diseases are linked to inflammation caused by poor diets.

Calories being equal, a serving of plainly cooked farro is healthier than a serving of white bread in the same manner that a serving of grapes is healthier than a serving of wine, etc. because of the inflammatory effects and associated chronic diseases linked to highly processed foods.

We have known for a while that calorie restriction works, we don't know why it works, there are various competing theories. People do not like to be hungry, it affects their mood and their cognitive abilities. The point of my comment was to stress that it may not be necessary to restrict calories in order to promote health, that link has not been definitively established because the cause for improved health and longevity through caloric restriction has not been determined.