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The do's and dont's of Intermittent Fasting when you have Anxiety

Updated: May 6, 2023

Intermittent fasting is all the rage.

When done correctly, it's amazing for balancing hormones and reducing anxiety. But when done incorrectly it can make your anxiety so much worse.

I've been intermittent fasting for about three years now and I LOVE IT.

Here's why:

Digestion takes work.

When you eat food, it doesn’t magically just ‘make’ energy for you. It requires many different processes and lots energy to actually break down those nutrients, assimilate them, absorb them, and then put them to use.

During the process of digestion, your body uses up a lot of resources in the form of blood, oxygen, and nutrients. So, when you’re constantly eating, your body is constantly pushing all those resources to your gut to allow you to digest your food.

And you know what else it’s doing in the process? Pushing blood away from your brain and muscles. Which may result in brain fog, low energy, fatigue, poor resistance to stress.

This can lead you to feel overwhelmed and maybe even anxious.

The composition of your gut microbiome is VERY important for anxiety banishment. What's cool (as least I think 🤓) is that fasting can actually change the composition of your microbiome!!

I’ve talked before about how feeding your gut the right things (aka lots of fibre) help to feed the good bacteria that go on to produce our anti-anxiety neurotransmitters. But it’s not just about what you feed your gut, it’s also about when you feed them—and when you don’t.

Your gut bacteria are very responsive to the presence and absence of food. When you remove food for an extended period of time, there’s a shift in the composition of the microbiome. Studies show that with 16 hour fasts, there’s a rapid expansion of a specific bacteria called Akkermansia muciniphila, which supports liver health, reduces inflammation, and supports a healthier gut barrier.

Reducing inflammation is KEY to saying baiiiii 👋 to your anxiety.

If you want to read more on how inflammation creates anxiety and what to do about it, check out this blog I wrote 👉

So here's the deal... any changes in bacteria populations are largely host-driven. What's neat is that the overall community is also largely driven by time of eating.

Different bacteria thrive at different times.

Basically, when you’re not eating one type of bacteria may thrive, and when you start eating, other bacteria may flourish and take over the other. This cycle repeats every 24 hours and changes when eating patterns change.

But when you intermittently fast, it can reinforce and reinstate those naturally occurring fluctuations by giving your body and GI tract time to rest and recover.

Think of this way. After a looonng day at work all you want to do is come home and crash on the couch, right?

Your gut is no different. It’s constantly being bombarded with food day in and day out, and sometimes it just needs a break, too.

If you're looking to break up with your anxiety gut health needs to be priority number one.

Priority number two is keeping your blood sugar balanced.

There's a common misconception in the health industry that in order to keep blood sugar levels stable you HAVE to eat every 3 hours. And while that can absolutely be helpful, sometimes that's just not realistic for everyone.

Keeping blood sugar stable doesn’t just revolve around how often you're eating. It’s also WHAT you’re eating, and what you’re eating actually plays a bigger part than when.

If you’re eating what I'm constantly telling you to eat (high protein + high fat + high fibre), blood sugar isn’t going to be an issue for you. But if you’re eating high carb, not enough protein, not enough fat, not enough fibre... then ya... your blood sugar is going to be all over the place.

In which case fasting is going to make the situation worse.

Blood sugar imbalance = hormonal imbalance = anxiety. Capiche?

Which brings us to reason number two why I love intermittent fasting. When done properly (i.e you follow my DO rules), it can be super effective for balancing hormones.

And this actually reducing anxiety!


Fasting on a 24-hour cycle allows you to align your fasting with your natural sleep/wake cycle. This is called your circadian rhythm.

Circadian rhythms play a big role in nutrient processing and hormone regulation. This is one of the 3291892189 reasons why sleep is SO important.

Let's chat hormones really quick.

Melatonin is the hormone that helps you fall asleep. Insulin is the hormone that regulates blood sugar balance.

Your last meal should always be 2-3 hours before. This is the start of your fast.

Do you struggle to fall asleep? Eating too close to bed can inhibit melatonin production leading to sleep problems.

Or do you wake up in the middle of the night? Say between 2 and 4 am? This is your blood sugar crashing in the middle of the night.

Again when you’re eating before bed, especially carb-rich foods, your glucose (blood sugar) spikes, you fall asleep, and then when it drops your body releases cortisol to get it back up.

What else does cortisol do? Wakes you up!

Melatonin interferes with the action of insulin, so when you eat late or snack at night, insulin isn’t going to function as well. When this happens glucose stays in your bloodstream, keeping your blood sugar levels high.

Overtime chronically elevated blood glucose CREATES anxiety.

Long story short, when done correctly intermittent fasting can actually help to balance hormones, improve sleep and reduce anxiety.

Am I saying it’s the solution to all of your anxiety woes? No. But it is a good tool to have and something I personally use.

Here’s my master list of DO's 👍 and DONT's 🙅‍♀️ for Intermittent Fasting

#1 do have a high-fat breakfast drink

There are a couple of reasons why I like having a fatty drink in the morning—and it’s not just because I think it tastes amazing.

When you’re doing a prolonged fast, the body goes into something called autophagy, which is like your cellular cleanup crew. They get rid of dead, worn out, and old proteins to make space for new functional ones. However, when you start eating, autophagy stops.

You're probably thinking... but doesn't adding in fat break my fast?

Honestly, it depends who you ask. I say it's fine. Especially if you're using the right type of fat.

MCT oil, for example, is metabolized differently than other fats, which is why it’s used during fasting. Instead of entering the digestive system and going to the liver, MCTs are absorbed directly from the gut into the bloodstream and skip the entire process of digestion, therefore not disrupting your fast.

So technicalllllly, your digestive system is still in the OFF mode.

Also, the other reason I love a fat-rich drink in the morning is to balance hormones. Carbs and protein require insulin (remember the hormone that controls blood sugar) to be metabolized, so when you load up your coffee or tea with milk and sugar, it spikes your insulin right out of the gate. Eventually, your blood sugar will come crashing, which will leave you dragging your feet, not to mention experiencing anxiety-like symptoms due to low blood sugar.

But with just fats, your insulin doesn’t spike and your blood sugar remains stable.

I love a mix of MCT oil and grass-fed ghee. It’s to dieeeeee for, and the butyrate (butyric acid) in grass-fed ghee helps to balance out hormones, reduce inflammation, and has many benefits to metabolic function.

I’m not a fan of coffee because I'm extremely sensitive to caffeine so I use Dandy Blend, a herbal coffee alternative.

#2 do listen to your body & EAT if you’re hungry

I can’t stress this one enough. SO many people ignore their hunger cues because they’re fasting and I beg you not to do this.

The second you get hungry... EAT!!

DO NOT push the fast just because you are trying to stay consistent with a 16-hour window every single day. If you feel like you need to eat, then your body is signaling that it needs energy.

This is especially important for women to note when they’re in the luteal phase of their cycle. Due to hormonal fluctuations, you’re not going to be able to fast as long because your body needs more calories, so honour that, listen to your body and EAT.

#3 do drink lots of water during your fast

Your body is made up of more than 60% water. Every metabolic reaction taking place in the body requires water and leads to water loss, so staying hydrated is just as important as eating that good protein, fat, and fibre.

Water is required for every function in your body—balancing pH, eliminating waste (especially important during a fast), regulating hormones, transporting nutrients to cells, and more. And a loss of just 1% of water from your body is enough to cause serious dysfunction.

Not to mention, water can also help to suppress some of the hunger pangs if you’re doing a prolonged fast that goes into the waking hours.

You should be drinking at least half of your body weight in ounces each and every day. That means if you’re 150lbs, you should be drinking 75oz of water daily, and more if needed during a fast.

I'm not even exaggerating I have had women message me saying they increased their water intake and that ALONE massively reduced their anxiety.

Do not underestimate the power of aqua you guys.

But keep in mind that you probably don’t want to be chugging water before you go to bed, because it’s going to interfere with your sleep. We don't need you getting up to pee 12 times a night.

#4 do time your fast properly

Women do better on an overnight fast schedule (eating lunch and dinner, fasting in between), while men can fast well into the day. Unlike men, women’s hormones are more sensitive to energy intake, and changing that too much can have a negative effect on your reproductive hormones.

I'm about to get a little nerdy but stay with me ...

Both men and women have something called the HPG axis—the hypothalamic-pituitary-gonadal axis.

This baby is what controls secretion of our sex hormones.

Here’s how:

1️⃣ Your hypothalamus (your brain) releases gonadotropin releasing hormone (GnRH) in regular “pulses”

2️⃣ GnRH pulses signal to your pituitary gland to release luteinizing hormone (LH) and follicular stimulating hormone (FSH)

3️⃣ LH and FSH then act on the gonads (ovaries in women, testes in men)

In women, LH and FSH trigger the release of estrogen and progesterone, and in men triggers the release of testosterone.

But the thing about fasting and hormones is that GnRH is super sensitive to environmental factors and can easily be thrown off by fasting, and even more so in women. So when GnRH gets thrown off, it throws your hormones out of whack.

Enter anxiety.

So, even just missing a single meal can put your body into alert mode, so you have to time your fast properly.

#5 do eat nutrient dense meals

This applies to you even if you aren't fasting, but if you’re reducing frequency of meal consumption you obviously want to bump up the nutrient density of our meals to ensure you’re meeting your macro and micronutrient needs.

And I’m sure you can guess what I’m going to say… PROTEIN + FAT + FIBRE at everrryyyy single meal. I cannot stress this enough.

It’s what’s going to keep you going through the day, it's what's going to balance out your hormones, support your digestive health and keep your anxiety far, far away.

#1 don't go over 16 hours

Most people like to fast for anywhere from 12 to 16 hours, and some people even beyond that. But for women, our hormonal fluctuations and sensitivities can make it challenging—and unhealthy—to fast for more than 16 hours.

Like I said before, our hormones as super sensitive to changes in energy balance, and when you’re fasting for long periods of time, especially into the daytime, you’re not only cutting back on calories consumed through the day because you’re skipping meals, but your leaving your hormones susceptible to changes, which can negatively impact your anxiety, not to mention your reproductive cycle.

If you find yourself feeling super fatigued and low energy, try knocking it back even further and do a 12-hour fast. Listen to your body. If it’s telling you 14-16 hours is too much, you need to take it down. This isn't a competition. Not every woman can do long-period fasting.

#2 don't skip the fatty drink (for black coffee or water)

Almost every time I talk to someone about fasting this is what they are doing... sipping on that cup of black coffee and breaking their fast sometime before lunch.


While it may be fine for some people (men primarily), we need that fatty drink to support blood sugar and hormones. The addition of something like MCT oil and/or grass-fed butter helps to keep insulin levels low. Remember insulin is responsible for keeping your blood sugar balanced.

When you go the entire morning with nothing but black coffee and water this impacts insulin production and causes your blood sugar levels to drop.

#3 don't surpass the 12-hour mark if you aren't eating enough

Your body needs energy to survive. Period. If you aren't eating at least 1600 calories a day, intermittent fasting is only going to do more harm than good.

If you find yourself feeling more stressed and more anxious, lacking energy and/or struggling to get out of bed in the morning. You need to be eating MORE.

I like to see my clients eating anywhere from 1900-2200 calories daily. And NO they do not gain weight. They're actually loosing weight.

Being in a caloric deficit doesn’t guarantee you weight loss, in fact it usually creates weigh gain. Your body needs energy to function, and without it, it’s going to hold on to that fat for dear life and slow down your metabolism.

Dropping your calories too low has a massive impact on your thyroid function. Surprise surprise, but restricting calories actually causes your body stress, which causes it to pump out more cortisol.

Too much cortisol causes all sorts of havoc on your body and is one of the causative factors of anxiety.

AND when you’re not not eating enough calories, you’re also decreasing your levels of your active thyroid hormone called T3. The thyroid produces two hormones: T3 and T4. T4 is the inactive version of T3 that is converted to an active state in certain tissues in the body; T3 is the active hormone that is actually utilized by the body.

When this conversion isn’t happening, it’s usually due to four reasons: inflammation, high cortisol, nutrient deficiencies, or intestinal dysbiosis… or maybe a combination of all four.

These four imbalances CREATE anxiety.

So, basically your thyroid needs food to function, so dropping your calories below 1600 is never a good idea which means fasting below 1600 is also never a good idea.

If you are fasting how can you be increasing your calories? Ya know?

#4 don't use fasting as an excuse not to eat

Look, I get it. When you're anxious AF you aren't hungry. The symptoms of anxiety suppress your appetite, so you don't eat which then makes your anxiety worse. It's a vicious circle.

If this is you, skip the intermittent fasting and you need to focus on bringing your blood sugar back into balance.

Try eating a small breakfast of fruits, nuts and seeds. Or mix protein powder with some water or almond milk. You can even toss almond butter into that and blend it up. Sip on bone broth throughout the day which is filled with vitamins and minerals. Avoid refined and sugary foods as this will make it worse. And drink plenty of water!

Just as an FYI - during your feeding window, you NEED to be eating a lot and giving your body the nutrients it needs to actually run properly. Do not fast if you cannot do this.

When you’re not consuming enough of the building blocks for hormones and neurotransmitters, your anxiety is for sure going to kick up. And you’re also not producing enough of the thyroid hormones needed to keep your body running.

Make sure you are eating at least 1600 calories, 90ish grams of protein, 74-140 grams of fat, and 25-35 grams of fibre daily, in your feeding window. This provides your body with the building block to build things like serotonin, dopamine, GABA, and other hormones necessary to keep your anxiety in check and your mood balanced.

#5 don't follow a fasting plan designed for men


We cannot practice the same intermittent fasting protocols as men do.

Men’s hormones follow a 24-hour clock. Their testosterone is highest in the morning and slowly dwindles during the day to reach its lowest in the evening. The next day, it repeats the exact same cycle.

Women's hormones follow a 28-day-ish clock. They do not follow the same pattern as men.

So, when you’re following an IF protocol designed for men, it’s designed to suit their hormone fluctuations—not yours. Testosterone is not as sensitive to changes in energy balance, so it’s not going to affect their sex hormones as it does ours.

This is why women do better on overnight fasts, whereas men can fast the entire day if they want and still be fine.

My partner can fast all day long, meanwhile I turn into the she-devil if I go anywhere over 16-hours.

Also you will notice you want be able to fast as long during your luteal phase. This is the second half of your menstrual cycle after ovulation. This is because your body NEEDS more calories during this time. It's quite literally building another organ (the endometrial lining).

Give yourself a break woman. Give your body nutrient dense food so she can.. oh you know... BUILD ANOTHER ORGAN! Every. Single. Month.

So there you have it! The DO's and DONT's of intermittent fasting for anxiety!


Looking for more resources? FREE CLASS: The Three Secrets to Natural Anxiety Banishment

Register for this pre-recorded 1hr seminar training on why medication, therapy and even meditation are not enough to banish anxiety from your life and what I recommend doing instead. CLICK HERE TO GET ACCESS!

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