Typically, people start feeling better very quickly. They will start to look at it not exclusively in terms of vanity (losing weight).
What surprised me, was so many ailments that I thought were part of aging or just something I had to put up with, were in reality the side effects or chronic overeating. Allergies, weird rashes, gut and stomach issues, sleeping problems, energy. My vision improved markedly. There is a kind of “clear thinking” that many people describe, or certainly I noticed a reduction in what I would call “Carb Fog” upon awakening in the morning.
Once in a while I will have a junk food binge like the old days. It just makes me feel sick. Still have a weakness for some carby foods, but the body naturally learns to prefer real food, it just does. I also learned right away what specific foods don’t agree with me. I used to eat so much, so often, there was no way to tell. Artificial fats mainly, just destroy my digestion. Cheese and butter OK, but I limit Milk, no corn syrup. Coconut oil for frying, or lard, tallow, butter, olive oil.
I started doing time restricted eating almost four years ago and have stuck with it. Lost about 25 pounds in the first three months and have easily kept it off. Started when I was 69 years old and the biggest surprise was the vast improvement with arthritis in my hands. Before I would occasionally have days when I could barely hold a pen; that hasn’t happened in years.