Low Carb Diet Side Effects

Are you wondering about low carb diet side effects? To be honest, some people do feel a bit wonky when starting a low carb diet. Not everyone mind you… but some people do. Here’s what I’ve heard from some of my clients. Let’s call it The Top 10 List of Common Side Effects. Drum roll please…

#1 Flu-Like Symptoms, Ugh!

You know how some days you just feel a little off and you think you may be coming down with something? You’re not actually feeling sick but you’re feeling kind of blah, maybe even a little achy. That’s what’s known as the “keto flu” or the “Atkins flu”. But don’t worry, it’s temporary and completely normal. Here’s why.

When you reduce the carbs in your diet there’s a lot less blood glucose circulating around in your bloodstream. And that’s a good thing. But your body is used to fueling itself with glucose. Now with less glucose it must find an alternate fuel source.  And that is fat… the fat you’re already storing and the fat you’re eating.  Your body turns that fat into ketones which it uses for fuel, and you enter a state of healthy nutritional ketosis.

So, it’s the transition from glucose to fat that could be making you feel less than great. On the bright side, when you’re in ketosis, you’re losing body fat!

#2 Not Tonight, I Have a Headache!

A common complaint I hear is about headaches. This also has to do with transitioning to fat when you cut down on carbs. I’m going to get a little “science-y” here, so bear with me.

If we can’t immediately use up the energy we take in from carbs, because we’ve eaten too many, that energy gets stored as glycogen molecules. Each gram of glycogen has 3 grams of water attached to it.

So, for the first few days of reduced carbs, you’re using your stored glycogen for energy. And that will make you lose water. Meaning, you will pee. A lot. And when you pee it’s not just water. There are electrolytes such as magnesium, potassium and salt being flushed down the porcelain bowl as well. And the loss of electrolytes is what’s giving you a headache. Ta da!

Want to get rid of the headache? Add a bit more salt to your food and avoid strenuous activities that make you sweat.

#3 Where’d My Mojo Go?

You may feel low energy and have to drag yourself around.  You may also feel a bit foggy brained. This is temporary and will last only a few days. After that you’ll feel your energy bounce right back up and the fog will lift.

#4 A Bit Backed Up

This side effect is less common, but it does happen. If you haven’t pooped in a couple of days, it doesn't mean you’re constipated. Think about it this way, less crud going into your body, less of it coming out.  That means you won’t need to go as often. If you’re having a hard time passing stool, then you’ll need to take some action.

I find that adding more fat to my meals works quite well. Seems the extra fat lubes things up!

And believe it or not, moving your body a bit more works to get the “traffic jam” moving along. For instance, walking can help to stimulate intestinal contractions. Who knew?!

#5 Dragon Breath

This side effect is common. It’s not that you get bad breath, but it smells different. I think it smells like acetone, maybe metallic or even kind of fruity. Remember the ketones I talked about earlier? They’re being released into your breath as your body is breaking down fat and protein for energy.  Sometimes that causes a change in your breath.

If so, it’s a sure sign you’re in ketosis and burning body fat. And that’s a good thing.

#6 Nutritional Deficiencies?

Imagine there’s a plate in front of you. On it there’s a juicy burger patty with a slice of melted cheddar on it. Next to it is a mound of steamed broccoli and cauliflower topped with a pat of butter. Beside the plate there’s a large bowl of salad with a colorful mixture of bell peppers, cherry tomatoes, purple onions, cucumber slices, chopped pecans and bacon bits. It glistens with an olive oil-based dressing. Does that look deficient in any way?

If you’re not sure what to eat, here’s where you can learn more about nutritious low carb diet foods.

#7 Careful What You Wish For!

What happens if you lose weight too quickly… asked no one ever.  Just so you know, this has never, EVER happened to me.  But it does happen to some of my clients. And, although it seems like a blessing, losing weight too quickly can have some drawbacks. Things like eventually slowing down the metabolism. And muscle loss could be a possibility. Add more carbs and weight loss will slow down.

#8 Moody Blues

Let’s face it, cutting out sweet snacks and ice cream from your usual diet is bound to make you a little sad and probably kind of cranky. And if you’re getting a headache or feeling flu-ish, you may be feeling less than sunny! Don’t worry, it’s temporary.

#9 Peak Performance in the Pits

Even lean athletes have heard good things about this way of eating, and they want to try it. And like you, they want to know about low carb diet side effects.

Let’s say you’re a gym rat. You love working out and the higher the intensity the better! So, what can you expect? Oh man, I hate to be the bearer of bad news, but you will likely crash and burn in the first few days. But, once you’re fat-adapted, you’ll be back, better than ever!

#10 FOMO (Fear Of Missing Out)

“What about all my favorite foods?”  Of course, you’re going to be giving up some of the foods you love. But your end game is to lose weight and get healthier.

I’m sure I don’t need to remind you that if you eat the way you used to, you’re not going to get the results you’re looking for. Hey, if I could be healthy and slim while eating Toblerone chocolate bars and Doritos every day, guess what I’d be doing?  But that’s not gonna happen now, is it.

Low Carb Diet Side Effects and Medications

The side effects we’ve discussed so far are mild and temporary. But there are times when things can go sideways.  That’s especially true if you’re taking certain medications. Not just because you’re following a low carb diet. It can happen any time you make changes to how you eat. And since I am not a doctor, I’m asking you to talk to yours.

A low carb diet will lower your blood glucose level. Your blood pressure may also drop. So, if you’re taking medication for either, you have to talk to your doctor who will adjust the meds.

If you think your doctor won’t support your decision to follow a low carb diet, simply explain that you’ve decided to cut sugar and processed food from your diet and you’re wondering how it will affect your prescription dosage. He or she will love your new health kick!

It’s a Wrap

I hope you noticed that low carb diet side effects are harmless and temporary. There’s no need to run for the hills! Hopefully I have eased your concerns about potential low carb diet side effects… not scared the daylights out of you!

My best advice is starting the diet on a Friday so you’re at home and can take it easy. That’s what I recommend for all my clients.  Have fun with this. Now go eat something delicious and nutritious!

Here's where you can learn more about working with me one-on-one. 

Return to our Low Carb Diet page.

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