I'm going to attempt to do the 16:8 plan which is just "don't eat anything for 16 hours" followed by "eat whatever when you're hungry during the next 8 hours." Given my late-rising, I can buy some hours easily by skipping breakfast (which has been nothing more than a PopTart every morning for years). Unfortunately it also means no snacking after about 8pm which is going to be difficult since that's TV-watchin' time.
Coffee and tea don't count as breaking fast, but the jury is somewhat split as to if it counts when you add a splash of half-and-half or not. I'm going to go with the theory that a tablespoon or so of half-and-half doesn't have enough calories in it to count as breaking fast. It is perhaps a minor cheat, but it doesn't seem catastrophic.
So the side effect of that is, whenever you eat anything at all, your body is going to go into that mode which means it's never actually burning fat. So if you eat a bunch of small meals/snacks all day long, you're keeping insulin production high all day long and your body is going to constantly prefer to use the new food energy and store excess and will never prefer to actually burn any of the stored fat.
So as I understand the theory, the traditional calorie restriction diet doesn't work so well because they usually encourage you to snack in small amounts to offset the hunger. As a result you're constantly telling your body that food is coming and to be ready for it. The decrease in actual calories eaten in turn causes your body to tend to reduce the calories it uses for basic functions (body heat, etc) instead of actually burning stored fat because insulin never has a chance to diminish.
@bigzaphod (hopefully you don’t mind me reply-guying and brain-dumping) Everyone’s body is different, so what works for you or me isn’t always transferable to others. Insulin doesn’t have to be a huge spike. A serving of pizza and grilled broccoli are processed with different levels of insulin. Your body can develop insulin resistance if you pound yourself with heavy amounts of insulin all the time. Insulin resistance can lead to pre-diabetes.
@JonathanGerlach health stuff is always so complicated and it doesn't help that virtually all sites/articles/videos about any of this are trying to sell something, too.
@JonathanGerlach but yeah things like developing insulin resistance seems bad... and eating a lot all the time seems like it would easily turn into that sort of thing. Our bodies love to adapt - it's kind of what they do. Sometimes that backfires.
And so the key to getting the body to actually dig deep and burn the old built up fat is to, basically, starve it a bit - allow the insulin levels to drop. That drop in insulin levels prompts the body to unlock fat in order to keep your body temp up, brain functioning, etc. But that takes time to happen - you have to literally not eat anything at all otherwise your body is just going to spike insulin production and assume a big meal is incoming every time you snack.