Is it permissible for a new Muslim to gradually accustom himself to fasting, similar to how children are gradually introduced to it? And is there a fatwa regarding this?

Fasting Ramadan is obligatory for every adult, healthy, resident Muslim. It is not permissible for a woman to intentionally break her fast before sunset, unless she fears significant harm from fasting. In such a case, she is permitted to break her fast and must make up the day she missed. She should be reminded of the virtue of fasting and the great reward of those who fast, to help her complete her fast.