Intermittent fasting (“IF” for short) is often lumped in with other trending eating strategies – namely, the Keto Diet – and labeled a “fad diet.” This is a negative connotation, of course, one that implies that IF is a flash in the pan rather than a viable option long-term.
Truth be told, IF is sustainable. It can also be one of the easiest and most effective ways to drop body fat and improve overall health – if you do it correctly. As with any diet, there’s a right way and a wrong way to do it. If you’re thinking of giving IF a try, avoid the below six mistakes to keep your fat loss on track and your muscle gains up, too.
What is Intermittent Fasting?
Before I get into the six mistakes, let’s have a quick refresher on exactly what this style of eating entails.
IF involves periods of fasting alternated with feeding “windows.” One of the most popular and effective IF schemes (and the method I prefer) is a 16/8 plan, where you fast for 16 consecutive hours and then consume all of your calories for the day in the following 8 hours. When you fast is completely up to you – you can fast from 9pm to 1pm the next day, 9pm to 11am, midnight to 4pm, whatever you want. A 16/8 IF plan is intended to be done every day, indefinitely.
A slightly more advanced version of this is an 18/6 scheme. Same concept: You fast for 18 hours every day and consume all of your food in a 6-hour feeding window.
This may seem like an obvious point, but I’ll mention it anyway just to be clear: Fasting means consuming zero calories. No food or calorie-containing beverages. In fact, I generally recommend avoiding zero-calorie drinks with artificial sweeteners during fasting periods, since the sweetness in them could raise blood insulin levels (the science is still inconclusive on this). While fasting, you can drink water, black coffee, and plain green tea. That’s pretty much it.
IF can be effective for fat loss, but it also offers numerous health benefits, including better insulin sensitivity, improved cholesterol levels, and enhanced immune function.
Now that I’ve covered the basics of IF, here are the six mistakes to avoid…
Mistake #1: Thinking intermittent fasting is too hard
I hear this a lot from people. The thought of eating nothing for an extended period of time (16+ hours) can be intimidating. “I’ll starve if I go that long without eating,” they say. Or, “I won’t have any energy and I’ll be a cranky as hell if I fast.”
First of all, your body will not starve by eating nothing for 16-18 hours – not even close. But also, intermittent fasting is way easier than you’d think; it just sounds hard if you haven’t tried it yet.
IF is so easy, in fact, that you’re actually doing it without even realizing it. Most people follow close to a 12/12 IF schedule – meaning, 12 hours of fasting alternated with a 12-hour feeding window every day.
For example, if you end your last meal around 8:00 pm and eat your first meal at 8:00 am, that’s 12/12. Even if you eat you last meal at midnight and eat your first meal at 8:00 am, that’s an 8/16 IF. Research shows that as little as a 12-hour fasting window can provide benefits.
Starting IF is easy. Just make sure you’re close to a 12/12 schedule. As that becomes easy, increase the fasting window while decreasing the feeding window by an hour each. Start with 12/12 and set a goal to eventually arrive at a daily 16/8 schedule. But take your time getting there. Do 12/12 for a few days, or even a few weeks, then step it up to 13/11 for the same amount of time, then 14/10, then 15/9, then 16/8. Trust me, it’s easier than most people think.
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Mistake #2: Thinking Intermittent Fasting is not healthy
Another thing I hear a lot is this: “Not eating for 16-18 hours – that can’t be healthy!”
The mental approach you take to your diet is critical for sustaining it long term. If your attitude is that the diet is unhealthy and you’re only doing it for quick weight loss, you’re setting yourself up for failure. Once your weight loss plateaus, you’re likely to say “Screw it” and go off the diet. But if you know the eat style you’re following is healthy, you’ll have a better chance of sticking with it and not violating Mistake #3.
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Mistake #3: Not sticking with IF long enough
It takes any system in the body approximately two weeks to change. If you’ve tried IF in the past for a few days but felt foggy, exhausted, and hungry, that’s because your body’s metabolic systems hadn’t adapted yet to a fasting schedule.
Give IF a minimum of two weeks, and you’ll notice how much better you feel in the fasted state.
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Mistake #4: Breaking your fast with a high-carbohydrate meal
At the end of a 16-18-hour fast (or even a 12-15-hour one), you may be feeling pretty hungry and tempted to splurge with a high-carb meal like pizza or a burger and fries. I’d suggest not doing that if you want to maximize fat loss.
IF allows you to be somewhat loose with your eating, but that doesn’t change the fact that high protein intake is important along with healthy, wholesome food choices. Coming off of a fast, I recommend a high-protein meal as opposed to one loaded with carbs.
Research supports my advice. One study found that when subjects consumed a high-carbohydrate meal, levels of a critical uncoupling protein decreased within an hour after the meal; subjects who consumed a low-carb meal, however, maintained elevated levels of the uncoupling protein an hour after eating.
Why is this important? Because IF is effective for fat loss in part because of uncoupling proteins. When you fast, it turns on genes that encode for certain uncoupling proteins and for enzymes that increase fat burning. The uncoupling proteins basically “poke holes” in the mitochondria inside muscle cells. The mitochondria are where most of your energy is derived from, especially at rest. By poking holes in the mitochondria, they produce less energy, so they have to burn far more calories to produce the same amount of energy in the form of ATP.
Don’t give into the temptation to go hog wild after a fast. I recommend consuming a high-protein (30-50 grams), low-carbohydrate meal to break your fast (your first meal in your feeding window). Some eggs and/or a protein shake are good options here.
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Mistake #5: Not training in your feeding window
I highly recommend not training in a fasted state, except maybe on the rare occasion that the only time you can squeeze in a workout on a busy day (or a travel day) is during your 16-18-hour fast.
Why am I so insistent on training during your feeding window? Because I believe it’s critical to train with as much energy and intensity as possible, and you’ll be better able to do that when you’re fed.
If you train fasted, you’ll also be shortchanging your results. It’s critical to have certain nutrients available around workouts for optimal gains in muscle strength, endurance, muscle growth, and even fat loss. It’s even more critical to have certain nutrients available for recovery immediately after the workout is over.
Also, study done in my old lab at Yale found that exercise actually decreased the boost in metabolism that fasting offers; more specifically, exercise decreases the production of the proteins that cause the boost in metabolism.
If you can’t train within your feeding window, do your best to have your first meal within two hours after your workout. That way, you at least get the critical amino acids and carbs to your muscles for adequate recovery.
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Mistake #6: Trying to build muscle with intermittent fasting
While IF is great for fat loss, it doesn’t work very well for making significant muscle mass gains. While you won’t lose muscle with IF, it’s very difficult to build with long periods of fasting.
Your diet should always match your goals. If you’re a bodybuilder or athlete who needs to add considerable muscle and strength to improve your performance, I would not recommend IF. Eating more frequently will be a better option for you.
However, if your primary goals are being lean (fat loss) and improving your overall health, and you’re content with your current level of muscle mass, intermittent fasting is a fantastic nutrition strategy to follow.
