The main change is really what you eat, not necessarily when. That said, when my brother recommended it to me, he said he did it with intermittent fasting as well., and he fasted (water only) for the first two days of it to kick-start the body's transition into ketosis (
).
So long story short, during this I ate like, one meal a day and had a snack or two.
The diet itself is high fat, moderate protein, little to no carbs, no sugars. To make it easier (
) I basically cut out all carbs and sugars. So no bread, pasta, fries, breaded meats, rice, sweets, sugary drinks, chips, potatoes, cereals, milk, etc.
You can have basically any meat -- even wings -- so long as they aren't breaded in flour or whatever. So steaks, grilled chicken, salmon, bacon, pork chops and what not is good to go. Gotta up the fat intake, so things like avocado, heavy cream, butter, dressings, olive/coconut oils (ranch, mayo and all that) are encouraged to be eaten and/pr cooked with. Veggies are good too (spinach, leafy greens), sans beans. Water is essential and basically the only thing you can for sure drink (black coffee by itself and I think unsweet tea is fine too). I also used those sugar-free drink mix powders to jazz up water.
Typical day for me was like:
Breakfast: Sausage link (or bacon strips) with two cheese eggs
Lunch: Breadless burgers (lettuce for bun) with avocado ranch dressing or some sort of salad or lettuce wrap variant
Snack: Salami slices with cheese
Dinner: Nothing. I didn't eat past 4 pm most days, and I find that I don't eat as much in general when I'm not at work.
I ended up cutting out breakfast a few days in and basically my window was 12-4. I don't recommend this, but I'm just telling you what I ended up doing.
As for exercise, I'd have to defer to someone else on that as I didn't have to do any of it. But from what I read/was told, a hardcore workout is not recommended on this diet, but some moderate cardio or light lifting session (in terms of time spent) might be OK. Will say that consensus is that exercise + Keto =
results.