is sustainable for you.

And since we're all different, this can vary greatly by individual.

In my case, I have difficulty fasting for longer than about 14-16 hours. So any program that calls for longer fasts isn't going to work for me.

I also wouldn't be able to stay on a program that calls for cutting carbs down to some ridiculously low number. So a strict keto diet is out in my case.

What has worked for me is as follows:
1. Setting up a daily caloric "budget" that puts me in about a 300-600 caloric deficit most days (I find daily caloric deficits beyond that to be unsustainable)
2. Focusing on nutrition first (i.e., within my daily caloric "budget", the highest priority goes to nutritious foods that I enjoy eating, less nutritious food is only allowed if there's room left over in the budget)
3. Getting sufficient protein, fiber, and "good" fat
4. Setting up a meal (and snack) plan that meets the above points
5. Gradually weaning myself off of sugar and refined carbs (this happens somewhat naturally if you observe all of the above points)
6. Doing a fasted workout six mornings a week that includes both cardio and resistance training
7. Allowing myself a cheat meal (or even cheat day) every now and then

A few other points:
- I still have a ways to go with sugar (going "cold turkey" on it didn't work for me) but my daily intake is significantly less than it used to be (and I continue to gradually reduce it).

- With regard to "nutritious food", there are several non-vegetable things I enjoy eating regularly. These include avocado, salmon, bison, eggs, nuts, seeds, berries, and kiwi fruit. For most vegetables, I find that I need to "doctor them up" a bit (e.g., make a salad, a stir fry, or dip them in some hummus). And on the vegetable front, I've recently tried to increase my intake of cruciferous vegetables and leafy greens (specifically, broccoli, cauliflower, spinach, and kale).

- I regularly consume chicken as it's just such a cheap source of lean protein.

- I regularly consume dairy but have decided to start cutting it back a bit. I've also decided to go with grass fed milk and butter (as well as grass fed beef).

- I regularly consume moderate amounts of whole grains, such as wheat, oats, and rice (the keto, paleo, and/or gluten free crowds have yet to convince me that these are per se bad for everyone).