This is a question from a follower. They have a late-night workout and then a protein shake. They also have an eating window from 3-7 pm, meaning that they fast from 7 to 3 pm. Here’s my answer.
As soon as you drink that protein shake your fast will have ended no matter what your declared “eating window” is.
There are several points about fasting that you need to understand;
- A fast means not taking in any nutrients. As soon as you take in nutrients of any sort, you’re no longer fasting. It’s not absolute; consuming 15 calories is probably not going to break a fast. A coffee or tea (black), or a lemon quarter squeezed into a soda water are fine. But a whey protein shake has about 140 calories in one scoop, and that’s the unflavored version. So even if you shake has nothing more than the plan protein you are consuming enough calories that your body will begin to metabolize the material that has just entered the body (i.e. food) and the fast is thus over.
- Just because something is called a supplement doesn’t mean it’s not food. Your body knows nothing about what you choose to call what you consume. All your body knows is that nutrition has been sent down the esophagus and it’s time to fire up the digestion process.
- Beware of lo-cal and no-cal items. Some of them have artificial sweeteners that trigger a metabolic response similar to sugar even though technically they have zero calories. Your body doesn’t really know or care about calories. It just knows how to respond to the material – liquid or solid – coming down the pipe.
- If you are fasting because you want train your body to consume fat for fuel – a common reason these days for fasting type eating patterns (rather than religion which was a common reason in the past) – you avoid food because you do not want to trigger an insulin response. An insulin response will stop your body’s ability to harvest fat from fat cells for energy. So as soon as you trigger the insulin response (which is what happens when you begin to eat), you shut down your body’s fat-for-fuel pathway.
- Some people adopt the new habit of intermittent fasting (IF) to lose excess fat – ref previous point. But then keep the old habit of immediately replenishing reserves after a workout. That’s OK if you are trying to build muscle and your workout was lifting heavy. But if your objective is to teach your body to harvest fat for fuel, well then, you are completely defeating that purpose if you consume a nice energy-rich protein drink that will leave any potential energy from fat nicely tucked away for storage in your fat cells.
- Rest assured that you do not need to consume any energy whatsoever after a workout. It’s a common myth that you do. Even a skinny person has tens of thousands of calories of energy tucked away in the fat that they have under all the skin on their bodies.
- If your body is demanding something after your workout, well, it’s just holding on to old habits. You’ve been nicely feeding it according to its demands. But you can take control. It’s late at night and you can just go to bed with a glass of water and leave your body to figure out how to fuel the energy need that you have just inflicted upon it. And then when you wake up, it’s usually not that difficult to avoid eating for at least the first while. Lots of water helps fill the void. And a coffee, if you drink coffee, it turns out that coffee has a satiating effect on eating. Eventually, your body will clue in that there is lots of energy available all over your body to harvest for fuel. Some bodies are slower than others to figure this out. And, alas, it seems for some unfortunate people, they simply cannot sustain protests that their bodies throw at them. But you seem to already be on a 3 to 7 eating window. All you have to do is be disciplined about making the fasting window a true fasting window.
One last comment; A four-hour fasting window is fairly impressive, but if you are having a protein shake late at night as in midnight, your actual fasting window is 3 to 12. That’s 9 hours, not 4. Nine hours is still not bad providing that the rest of your fasting period is truly fasting.