Hi Gail, if your last meal is 6.00pm at night and your first meal the next day is 12.00 noon that is 18hrs, is that what you mean? A lot of fasters can go through to 6.00pm that following night and only having liquids, clear broth or teas, water all day then 500cals in their evening meal 🙂 hope that helps. Of course you can break it up and have soup or something light for lunch at noon. Country gal

Gail,

You are indeed in a muddle.

If you are trying to do 5:2, then I’m afraid it sounds as if you are doing it wrong.

With 5:2,
The day before your fast you eat normally. You go to bed.
The fast day, you get up and eat 500 calories or less during that day. You go to bed.
The day after your fast, you get up and eat normally.

So this covers roughly a 36 hour period (day before evening meal at 7pm, sleep, fast day maximum 500 cals consumed between 7am – 7pm, sleep, day after eat normally). If you work (and sleep) odd hours, then you will need to account for that.

If what you are trying to do is 16:8, it’s very simple. In every 24 hour period you fast (i.e. don’t eat) for 16 hours, and then confine your eating to an 8 hour window.

If you are trying to lose weight you need to restrict your calorie intake so you should follow 5:2 as indicated by Happy Now.

In that case I suggest you do some reading regarding the health benefits of fasting and the best way to achieve them, there is a lot of information out there including research by Walter Longo and Krista Varady. It would appear that the longer the interval of fasting, the greater the benefit.