So far, I've gone two days with only a single meal around 8pm both days. Will probably do it again tomorrow, and then when I get home, I'll eat normally, and then restart on Monday.
The hardest thing so far is finding something for my brain to focus on instead of using my hands to snack on junk food. It's a bad habit that I need to break, looking over at my passenger seat where I normally keep my snacks for the road and grabbing something. So far, I haven't grabbed anything, but I keep looking over as if there's something I need over there. I think once I stop looking over, it'll have gotten easier.
Another upside to this is that I'm saving a ton of money on food, since I'm literally just not eating... And I don't go into the truck stops and get food, except to get food for evening meals if I run out (which I'll probably have to do tomorrow, since I probably won't be home until Saturday...).
I bet you've lost five pounds already!
It takes about 18 hours or so to enter ketosis (i.e. that means zero
calories taken in for 18 hours) so when you eat only one meal a day, you enter ketosis for short time every day. Ketosis is basically when your body has switched from burning carbs to burning fat for fuel. Now, if your one meal is nearly all fat and protein and no, or almost no cards, then it doesn't take as long for your body to go back into ketosis after your meal and you burn more body fat for fuel.
As for snacking, try changing your snacks to something that isn't carbs. Beef jerky or any of the dozens of Keto snacks that they sell at Walmart. If you snack on something that has almost all of it calories from fat, it will have less of an insulin reaction and help keep you in ketosis but you have to be careful not to over do those kinds of snacks because your body isn't going to burn body fat if you're constantly feeding it fat filled snacks.
Now, if you skip one of your daily meals and go an entire 48 hours between meals once every so often then, not only are you going to be burning body fat but the stress will tell your body to start getting rid of things it doesn't need, like warn out cells, viruses and other junk in your body. This is called autophagy and its where you really get some super awesome health benefits from fasting. Also, once you're fully into ketosis, you won't feel hungry. From what I've been taught, a three day (72 hour) fast is just about the ideal length of time to maximize ketosis and autophagy in the average person but most of what I've seen also says that long fasts (three days or more) shouldn't be done more than once a month and it seems like doing one of those once or twice a year is a pretty common thing for people to do. The point being that you get better benefits from fasting if you're not doing it constantly.
So, once you start getting used to it and it doesn't feel so hard, eat your Friday meal and then try going one whole weekend without eating. That is, don't eat again until meal time on Monday evening. In fact, I think I'm going to try to do that myself this weekend. I've never fasted for that long and I have to work this weekend so I'm not sure I'll make it but I'll give it a shot. From what I hear, it's fairly easy to go that third day without food because your body will be fully into ketosis and will have figured out that your stomach being empty isn't the end of the world that it was telling you it was during days one and two and it stops producing the hormone that tells your brain that you need to eat something.
Lastly, I think the basic idea here is that God never designed our bodies with three full meals a day plus snacks in mind. That's a luxury that western culture and a free market society, (not to mention advertising campaigns from big food companies), has allowed us to grow up with but when you have to hunt and or grow your own food, it makes sense that you're going to be working much harder, eating less often and consuming far more fat and protein and far fewer carbs. It's the way Noah would have eaten with less wine.