How to start fasting

I fast until 11 or so, other than green tea and black coffee. I can't say how long it took to get used to it because it wasn't a conscious choice, I'm just happy to not eat before then and find that making myself have breakfast makes me run out of calories earlier in the day.

I don't think there are side effects per se, you might be hungry but you're not fasting long enough to get weak or wobbly or anything unless you have an underlying health issue.

For me the main benefit is that I get to eat all my calories in a smaller window, which means bigger, bulkier meals, which I like.

Exercise if you want to - personally I'm not a morning exerciser, but that's a personal thing. Again, you're not fasting for a long period of time, so you shouldn't be too weak to exercise or anything..

1 &2. I started fasting after I was in ketosis so I had zero symptoms when I delayed my first meal until 2pm. I've read headaches and hunger are common if you're not in ketosis and are new to fasting.
3. I drink water and coffee, 2 cups, each with 1tsp. Heavy cream. Sometimes I have bone broth with salt. I keep my intake limited to <50cal.
4. Benefits of short fasts, less than 24 hours long, I avoid hunger while eating 1200-1500cal/day. I think less about food and enjoy meals more.
5. You can exercise while fasting. Initially, play it by ear, see how you feel and start easy.

I highly recommend reading Dr.Jason Fung's Fasting book. He covers the basics of short and long fasts. Or, look up his website, Intensive Dietary Management, for the same info found in the book.

It only took a day or two for me. In fact I I intermittently fast till 11 most days. I've had zero side effects. I stop eating at 5pm. It seems to control my appetite. I don't do any diet I pretty much eat whatever I want within my calorie goal and within an 8 hr window. I think you will find it easy to put off eating until 11. Be sure and drink water.

I'm not formally fasting, but I have delayed breakfast by several hours to maximize my fullness compared to when I have calories. It has eliminated what was my morning snack, but has been very workable for me so far. I'm only sorta-kinda fasting because I am definitely hungry when I wake up and feel a little lightheaded without something right away. This is typically what I do on a weekday:

1. 6am I have a low sodium V8
2. 7:30-8:30 I nurse a cup of coffee with half and half.
3. 10am eat my breakfast which is usually a boiled egg on crispbread with an orange.
4. 12pm (or as late as 1pm) eat my lunch which is usually a soup or sandwich or meat on crispbread, a serving of veggies and maybe fruit as a "lunch dessert."
5. 2:30pm (or as late as 3:30 pm) have a snack which is usually watermelon because it is like crack to me.
6. 6pm-7pm is dinner.
7. 8pm or later--if I have calories left, I will have a "dessert" which is sometimes more watermelon, or cottage cheese, or popcorn.

I used to eat all of my breakfast around 7am, but it was really hard to make it to AM snack and lunch. Nursing the coffee really seems to help and I get to have more of that "full" feeling I enjoy. Plus, switching up the timing of my foods keeps me mentally interested in "dieting."

1. How long does it take your body to get used to not eating until later in the day? I found it happened quite quickly. Now, I was already in the habit of three meals a day (no snacks), so I would eat a very small breakfast and then not have anything until lunch. I think this made it easier because I was used to a break. I was also doing lowish carb eating before I started fasting, and I think that helped too.

2. What are the side effects when you first start? I will probably start next Saturday so I can keep tabs on how I feel.
I didn't really have any side effects. Obviously, I was thirstier and drank more, because I wasn't getting water from food, but that wasn't a problem. I usually do 24 hour fasts, and still tend to get hungry mid/late morning, but if I ignore it, it goes away. I find hot drinks help to distract me from hunger. By the afternoon, I'm fine.

3. Is there anything you can eat/drink during your fasting period? Water? Tea?
It really depends on whether you're following a particular programme. Water is fine, and I think a lot of people would say black tea and coffee, and herbal teas are fine too. Some people have bullet-proof coffee (very high calorie, so I don't normally, but have sometimes put a tiny bit of coconut oil in black coffee). I do have tea and coffee with a little bit of whole milk, which is breaking the rules, really, but helps me stick to it. People have different views on drinks with artificial sweeteners. I prefer not to use them.

4. What other benefits are there to fasting?
You could look up Dr Jason Fung, who has written and spoken extensively on the subject. I've got his books, but there's also lots of information on his website or on his youtube channel. Personally, as well as the possible health benefits, I just find it easier. It's so easy to just not eat.

5. Should I exercise during my fast in the beginning?
I'm sure it's fine to exercise (I exercise when fasting), but if it's easier for you, it might be best to save exercise for non-fasting periods.