Can I eat/drink some food and still be fasting?

First, please drink water. Fasting or not.

Second, if we are talking about semantics only, then no you can not. Once you consume food energy — whether it’s in solid or liquid form — you are no longer fasting.

As much as I like semantics, there’s more going on here.

Your body doesn’t deal in absolutes. There is no single switch tucked away in your digestive system somewhere that flips from “fasting” to “not-fasting” once you eat a single calorie. What is happening is that when you are fasting, there are certain processes that your body already does that are more pronounced/diminished when you’re fasting compared to when you’re not.

If you start consuming calories during a fast, at some point all those processes would be the same as if you were eating normally.

So what does that mean for you?

It’s not black and white. Fasting actually exists on a spectrum. This means that you can have the BARE MINIMUM of calories, and your body still “thinks” you’re fasting.

This does not mean that you can try and hoodwink your body by sneaking calories when you can.

It also does not mean you can put milk in your coffee.

By implication, coffee is allowed. So is tea. Diet soft-drink, and so on.

What do those three things I mentioned have in common?

They are each 5 calories per serve.

That is why you can have coffee/tea/diet soft drink and still be fasting because it contains a negligible amount of calories.

Your milk by comparison has over 20x the calories.

So no you can not put anything over 5 calories in your digestive system at any one time to still be fasting.

How long should I be fasting for?

I don’t recommend putting time limits on fasting for a few reasons. Keeping on with the spectrum idea, your body isn’t waiting until the clock strikes hour 16 before it gives you the benefits. It’s not holding out on you. These benefits will of course manifest in different stages, so all you need to do is fast for sufficiently long enough to get the benefits. The literature that’s out there suggests that 8–12 hours and onwards is sufficient for this purpose. So ideally you would aim for around that 12 hour mark, but keep in mind that the longer you fast the more time you are spending in that physiological environment elicited by fasting

The actual length of time you fast for should be as long as you can without killing someone AND still be able to eat your day’s worth of calories in the time remaining in the day — remember this isn’t caloric restriction. IF shouldn’t be hard. There’s no benefit to sitting across from a clock whilst your stomach rumbles. That’s self-flagellation. No thanks.

Isn’t breakfast the most important meal of the day?

No. It’s not. It never was.

It’s well documented now that John Harvey Kellogg invented this phrase to help market his new breakfast cereal: Corn Flakes.

It was such a successful slogan that it remains a part of conventional wisdom.

Breakfast has no nutritional significance. It is perfectly fine to skip it.

Can I exercise while fasting?

Yes. But understand that your body is in a no-food environment. Depending on the situation, you might be running on glycogen stored in your muscles, or glucose created through gluconeogenesis in the liver. You will experience this as feeling flat and tired compared to when you eat before you workout as normal.

There is nothing inherently wrong with training while fasting, only that your performance in the gym is diminished slightly. If you can accept that, or force yourself to make up that difference with discipline in the gym, then train hungry.

What food should I break the fast with?

How about what you shouldn’t break your fast with. Corn flakes qualifies, but more generally it’s foods with a high glycemic index. A high glycemic index means that a food increases your blood sugar levels more than a low glycemic index equivalent. The way the body lowers blood sugar is through the hormone insulin.

When you fast, your insulin sensitivity changes. The best way to think of insulin is as a storage hormone: When you’re fasting your body is getting ready to store any food that does eventually make it past your mouth. One of the ways the body modulates this is through insulin sensitivity — which is just that, your body’s sensitivity to insulin.

So when you’re fasting, your body is priming itself to store something. If you then make that same something a food which is already going to maximise insulin secretion, that, in tandem with your increased insulin sensitivity will mean that that food is much, much more likely to be getting stored as fat.

So there you go, the 5 most common questions I get asked about IF.

I am just trying to make things easy for you, so you can take this information and smash your goals. That’s all.