You don’t want to not eat, it usually has the opposite affect from what I’ve seen. A change in your diet and an exercise routine can help a lot with some time.

the usual suspects are sleep, medication, diet (what you eat, not necessarily focusing on how much), activity. certain medications or conditions can make losing weight very difficult and you should consult a doctor about it. Sleeping too much can get in the way of activity and weight loss. But again certain medications/conditions make you sleep more. Choosing what you eat and making an effort everyday to be active are the easiest to control factors. As most doctors will say, exercise is the miracle pill for better health and longer life 🤷‍♂️ the intensity depends on the person and current activity level, but daily effort makes big improvement