“OMG, like, won’t intermittent fasting burn muscle and crash your metabolism, bro?”
Great question. The truth is, intermittent fasting challenges many of our longest held assumptions about nutrition. Hell, it’s a slap in the face of most of what we’ve been told from an early age about healthy eating. As a result, intermittent fasting myths are bountiful.
So, what’s the truth? I admit I was a skeptic of fasting. Now, after using it myself and with dozens of clients, I no longer doubt i’s efficacy. But first, let’s flashback. As your average middle-class midwestern kid, I heard all the same things you did.
“Breakfast is the most important meal of the day.”
“If you skip meals your body will think it’s starving and your metabolism will crash.”
“You should eat more often to stoke your metabolic furnace.”
As a result, I carried Tupperware and pre-packaged snacks labeled as healthy. And I spent plenty of money on supplements. It was all to make sure I had protein every few hours. Unfortunately, I was never able to stay muscular and lean with this approach.
What I really needed is what everyone needs: a lifestyle to improve life without consuming it.
That goes hand-in-hand with a little self-control in the kitchen to create the caloric deficit needed to lose fat.
Let’s begin by destroying the nutrition dogma holding you back.
Breakfast Is NOT The Most Important Meal Of The Day (But Damn, I Love Me Some Bacon)
When I was a kid, I’d get up early and wolf down some cereal before heading to school. After all, breakfast was the most important meal of the day.
Where did this belief come from?
Well, we were led to believe skipping breakfast would lower your blood sugar. You’d get lethargic and start sliding into starvation mode. By eating breakfast, you’d jumpstart your metabolism and go into fat burning mode right away.
Let’s start with the blood sugar and insulin argument. Insulin sensitivity is how sensitive your body is to insulin in response to eating. The better your insulin sensitivity, the more likely you are to lose fat and gain muscle. Proponents of breakfast say insulin sensitivity is highest in the morning at breakfast. They correlate breakfast with improving insulin sensitivity.
The truth is insulin sensitivity is highest after fasting, which happens during the 6-8 hours you’re sleeping. This coincides with breakfast time.
So, is breakfast truly magic?
Sorry, but no. Your insulin sensitivity is highest because you haven’t yet eaten, not some magical aura around breakfast.
Extending the time between your meals can boost insulin sensitivity. Avoid sugar bomb foods like cereals, donuts, and even bagels. When you boost insulin sensitivity, you reduce your chance of diseases like diabetes and heart disease that plague the western world.
You’ll also lose fat and build muscle more easily than ever before.
And when you eat less often?
Call me crazy, but the more I think about preparing and eating food, the more likely I am to overeat. It’s not rocket science to consider the more often you eat, the more likely you are to overeat. And when you overeat, you gain fat.
Breakfast is not a magic fat loss solution. Most Americans eat breakfast. 70% are overweight or obese.
Note: I love breakfast! There’s nothing wrong with it, but nothing inherently great about it, either. I still enjoy bacon and eggs. I just have it later in the day or on weekends. Still, there’s nothing inherently great about breakfast.
Eating More Small Meals Won’t Lead to Faster Fat Loss
It’s been common practice to recommend three to six or more small meals throughout the day. As the idea goes, eating more often spikes your metabolism, helping you burn calories and run “hot” throughout the day. This stems from the thermic effect of food (TEF) which is the energy your body expends to break the food you eat into usable nutrients.
It’s thought the more often you eat, the more active your metabolism stays. You’ll burn more calories and “keep the metabolic furnace going.”
The only problem?
TEF only makes up for about 5% of the calories you burn each day.
Plus, the thermic effect of food is directly proportional to caloric intake (the number of calories you eat) not the number of meals you eat.
This means it doesn’t matter if you have ten 200-calorie meals or two 1,000 calorie meals. The thermic effect of food for 2000 calories is going to be damn near identical.
At the end of the day, your metabolism from TEF increases to match the size of your meals, not how often you eat. That’s why you feel warm, relaxed, and sleepy after a big plate of spaghetti or Thanksgiving dinner.
Remember, the successful fat loss comes down to calories versus calories out above all other factors. If you’re overeating to keep your metabolism going but still end up in a caloric surplus, you will gain fat.
In the case of intermittent fasting, you’ll eat fewer, but larger meals. As long as you’re in a caloric deficit, you’ll lose fat and feel more satisfied after meals.
Fasting Doesn’t Crash Your Metabolism
The most common argument against Intermittent Fasting is “not eating puts your body in starvation mode.”
For starters, we’re talking about using short-term fasts of 12-24 hours, not medically supervised week-long fasts nor long-term extreme caloric restriction or disordered eating like anorexia.
But even with longer-term fasts? The evidence does not support the starvation mode argument.
Intermittent fasting uses shorter eating windows on a daily basis to limit caloric intake, so you do lose fat. That said, some studies show an increased metabolism with fasting diets up to 48 hours due to increases in adrenaline in your body.
According to sources cited from the Ultimate Guide to Intermittent Fasting by Mike Matthews, your metabolism slows by only 8% after 60 hours without food.
The truth is intermittent fasting won’t crash your metabolism. To the contrary, the release of adrenaline from fasting can boost your metabolism to accelerate fat loss.
Fasting Doesn’t Decrease Brain Performance
Glucose is the primary source of fuel for the brain so it’s easy to see why not giving your brain a constant supply of glucose could be problematic.
Here’s the problem with this belief: your body can produce glucose from stored fuel via gluconeogenesis, the process of turning stored fuel into glucose.
Even with low-carb intermittent fasting diets, your brain can still generate fuel via ketone bodies from breaking down fat.
When you fast, you’ll likely notice increased mental performance, clarity, and focus. The idea of getting more work done in less time should be enough to entice you.
Personally, I feel like I’ve gotten a hold of NZT like Bradley Cooper in Limitless when I’m fasting. So, how does this focus work? There are two key factors at play.
First, fasting increases epinephrine and norepinephrine. Since you’re going without food, your body triggers a small stress response, releasing adrenaline during periods of fasting to break down stored fat as fuel, which gives you more energy and focus.
Second, fasting triggers the release of brain-derived neurotrophic factor or BDNF.
BDNF has been shown to support the survival of existing neurons, boost the growth of new neurons and synapses in your brain, improve memory, learning, and thinking, and potentially reduce depression and later on, cases of Alzheimer’s.
The bottom line: Fasting won’t decrease mental performance, it may increase mental performance, focus, and brain health.
Okay, So How About Fasting and Muscle?
As a former skinny runt who had to fight tooth-and-nail to gain even a smidgen of muscle, I was terrified of losing lean muscle when I started fasting. But as covered above, starvation mode is completely overblown. It takes long-term fasting (days, not 16-24 hours) before your body starts breaking down muscle tissue for fuel.
But what about eating frequently to stay anabolic?
As it turns out, how often you eat is much less important than what and how much you eat, especially for building muscle.
If you eat enough calories and train hard, you can build muscle. Heck, this study found IF diets to be better at maintaining lean muscle during fat loss and this study found Intermittent Fasting style diets to be more effective at retaining lean muscle.
As the first law of fat loss is you must create a caloric deficit, the first law of building muscle is you must create a caloric surplus. If your primary goal is to build muscle, IF might not be optimal simply because it’s tougher to get your calories in.
But you can build lean muscle with intermittent fasting as long as you’re consuming enough calories, protein, and following an intelligently designed workout like the custom workouts I create for my clients.
No, Your Body Can’t Only Digest 30g of Protein At Once
In fitness circles, it’s been popular to recommend eating 20-30 grams of protein every few hours to maximize protein synthesis and muscle gain. It appears much of this evidence has been overblown, often to sell more protein supplements. (No surprise most servings of protein powder are 20-30g each, right?)
When you apply common sense, this myth seems even more ridiculous. I have a hard-time believing generations of humans would have survived periods of scare food, let alone caveman times if they could only digest 30g of protein while feasting on a beast around the campfire.
Luckily, we have more than common sense to support this notion; we have #science. This study found eating the entire days’ worth of protein in a 4-hour window (followed by 20 hours of fasting) didn’t negatively impact muscle preservation.
Much like total calories are more important than having a bunch of small meals throughout the day, your total intake of protein is more important than small, frequent feedings.
As usual, the health and fitness industries tried to make this much more complicated than it needs to be, often to fill their coffers and get you hooked on a steady diet of 30 grams per scoop protein powder.
The bottom line?
There is nothing wrong with having more, high protein meals, but it’s not magic either. You can enjoy larger meals like a 12 oz ribeye steak with intermittent fasting and know your body will break down the protein into useable chunks to support your #gains.
If You eat After 8, You’ll Gain Weight, Right?
In a word, no.
Remember the most important component of fat loss. It all comes down to calories in versus calories out, not to avoiding carbs, eating six, satisfying meals throughout the day, or perfectly timing your meals after your workout.
Preparing for my last photoshoot, I routinely ate after 8:00 PM and everything worked out okay. Remember, calories are king.
In fact, I’m going to recommend you eat the majority of your calories in the evening.
The truth is, eating in the evening particularly carbohydrate-rich meals, helps you synthesis serotonin, the primary hormone for helping you relax and unwind. Eating carbs also help suppress cortisol, the primary stress hormone responsible for you feeling anxious and alert. If you’ve ever felt tired and wired–exhausted but antsy around bedtime, there’s good chance your cortisol is spiking in the evening. Moving your carbs to the evening may help you relax and fall asleep.
Eating more of your calories at night will help you reduce stress, relax easier, and potentially improve your sleep.
And socially? Well if you’re like most of the busy people I work with in the Bach Performance Online Coaching program, you have business dinners, family meals, or social events in the evening. By limiting your calories early in the day, you’re able to enjoy these events fully, and eat like a king (note, not a peasant on crap food), and still get in great shape.
Yeah, But Won’t I Be Hungry?
I’m going to give it to your straight, no chaser: Yes, you will be hungry when you first start intermittent fasting.
After the first five days or so your body will reset your hunger signals this is necessary because frankly, most people don’t know what real hunger feels like. Understanding and managing hunger is an essential component of fasting and any successful dieting–you will be hungry. Accept it and move on.
But even more important? We live in a time of excess. There’s a good chance the hunger you feel is more likely from being systematically trained to frequently. Non-surprisingly, there’s a term for this: hedonic hunger, the increase in eating due to our habits, rather than the actual need for food. This is a huge reason for all the weight-related issues and yes, the extra layer of flab hanging over your jeans.
The truth is, managing hunger is an essential skill for anyone who wants to get in shape and stay healthy and fit. Intermittent fasting breaks you of the hedonic hunger habits holding you back from the body you want and deserve.
I promise I’m not just blowing smoke up your ass here. Research from this study has shown eating larger, but fewer meals can help you control hunger.
Anecdotally, I’ve found the more often I eat, the more likely I am to sneak in a few hundred more calories throughout the day.
Coming back to the most important rule of fat loss (creating a caloric deficit), if you over consume calories it doesn’t matter how often you eat, you will lose fat.
Remember, if you have weight to lose it’s because you’ve over consumed food. You need to break the cycle of addictive style eating and constantly thinking about food if you want to lose weight. The best eating style to help you crack the code and look great naked while eating like a king? Intermittent fasting.