The Low-Carb Diet Side Effects and How to Address Them

The Most Common Low-Carb Diet Side Effects

The Low-Carb Diet level of the Primal Diet can provide various positive health effects on insulin resistance, blood sugar levels, mental function, cardiovascular performance, autoimmune function, weight management, and cancer because of reducing carbohydrate intake.

Decreasing carbohydrates to about 50 grams daily can lead to side effects in sensitive individuals, especially during the early adaptation phase.

These side effects are generally temporary and will fade away as the body gradually gets used to burning fat instead of carbs. Let’s learn about these side effects and ways to address them.

Keto Flu

One of the most common Low-Carb Diet side effects is a set of symptoms known as keto flu, which includes nausea, dizziness, muscle cramps,  fatigue, and brain fog [1] [2].

These side effects occur because when you consume fewer carbohydrates, your body uses up glycogen stores and starts losing water and electrolytes.

To minimize these side effects, drink enough water and use electrolytes (sodium, potassium, magnesium). You can simply add salt to water and foods to make up for the lost electrolytes.

Also, reducing carbohydrates gradually can significantly reduce side effects. Remember that the Primal Diet is all about progress, not perfection.

Constipation

Another common side effect of the Low-Carb Diet is constipation, which occurs because of the digestive system’s reactions to losing water, leading to changes in bowel movements.

Each gram of carbohydrates contains 3 grams of water, so reducing carbs means losing water [3] [4].

Although it is a temporary side effect and gets better as your body gets fat-adapted, you can alleviate it by consuming low-carb, high-fiber vegetables like spinach, kale, broccoli, and chia seeds.

Also, drink a lot of water throughout the day to avoid dehydration, and consider adding magnesium supplements after consulting a healthcare professional.

Bad Breath (Ketosis Breath)

When you consume fewer carbohydrates, your body enters a fat-burning state called ketosis, which leads to ketone production. Ketones include acetone—a byproduct of fat metabolism—which is released through the breath, resulting in a distinctive, fruity, metallic, unpleasant smell [5].

To avoid bad breath, drink more water, consume less protein, brush your teeth regularly, and chew sugar-free gum or mints.

Fatigue

Before going low-carb, carbohydrates are the main sources of energy in the body, so reducing them can cause fatigue, physical weakness, or low energy levels [6] [7].

These symptoms will all be removed as fat replaces carbohydrates and becomes your main energy source. Also, fat will provide more energy levels than carbs.

You just need to give your body a week or two to adapt to the fat-burning state. Also, increasing fat consumption can speed up your recovery.

Muscle Cramps

As the body excretes electrolytes as a result of lowered carbohydrate levels, the body goes through electrolyte imbalances, causing muscle cramps, especially leg cramps at night [8] [9].

To avoid muscle cramps on the Low-Carb Diet, you just need to consume electrolytes, especially sodium, potassium, and magnesium, in the form of salt or supplements.

Also, foods like avocados, leafy greens, and nuts are common low-carb sources of these minerals.

Digestive Issues (Diarrhea)

A sudden increase in dietary fat can disrupt digestive function and lead to diarrhea or frequent loose stools in some individuals [10] [11].

The key to avoiding such symptoms is a gradual transition, i.e., slowly reducing carbohydrates and increasing fat consumption to enable the digestive system to adapt to metabolizing fat.

Also, consuming low-carb vegetables and enough water can help alleviate the symptoms and rebalance digestion.

Heart Palpitations

Electrolyte imbalance caused by decreasing carbohydrate intake and reducing sodium and potassium levels can affect heart function, resulting in irregularities in the heartbeats, heart palpitations, or AFib (Atrial Fibrillation) [12] [13].

Drinking adequate amounts of water, increasing salt intake, especially after losing initial water weight, and consuming high-potassium foods like avocados and leafy greens can alleviate these symptoms.

Of course, after adapting to the new low-carb eating style, all these side effects fade away, as various studies indicate that the Low-Carb Diet can decrease the risk of coronary heart disease [14].

Sleep Disturbances

Sleep disorders are among the common Low-Carb Diet side effects at the beginning, with symptoms like difficulty falling asleep, insomnia, waking up frequently, or restless sleep.

Metabolic changes that occur as a result of decreasing carbohydrates can reduce serotonin production (which comes from carbohydrates), disrupting sleep patterns.

Sleep disorders can happen during the early stages of going low-carb, and as your body adapts to low levels of carbohydrates, your sleep quality significantly improves [15].

Consuming more magnesium, fat, and protein before bedtime can boost relaxation and stabilize blood sugar levels during the night.

Mood Swings and Irritability

Any kind of dietary changes may affect mood. However, shifting from carbohydrates to fat as the main source of fuel may cause more significant results, such as irritability and mood swings because of drops in blood sugar levels [16].

Again, these symptoms are temporary, and fat-adaptation will surprisingly improve mood and mental function. It can also positively affect disorders like anxiety and depression [17].

Consuming nutritious, low-carb foods on a regular basis can control hunger and blood sugar drops, which can prevent mood swings. Proper hydration and enough sleep can also improve mood.

Slow Weight Loss

The initial weight loss in a Low-Carb Diet is usually water weight loss, which can be rapid at first but slows down after a few weeks as you consume enough water.

At the beginning of decreasing carbohydrate intake, your body uses all the stored glycogen, which releases lots of water. This initial drop is water weight, not fat. After this initial phase, fat loss becomes slower and more gradual.

Also, creating a caloric surplus by consuming more calories than you burn can hinder weight loss.

The best way to maintain weight loss speed is by balancing the macronutrient ratio, i.e., carbohydrates, fat, and protein. Also, remember that weight loss takes time and is a gradual process. So, take your time and stick to the plan to get the best results without serious side effects.

Carbohydrate Cravings

When you start a Low-Carb Diet after a high-carb diet, you may experience carbohydrate cravings because your body tries to adjust to lower levels of sugar and refined carbohydrates.

This process of shifting from glucose (carbohydrates) to glycogen (fat) as the fuel source takes time, which is why we crave carbohydrates; we are used to them.

Also, consuming carbohydrates, especially sugar, stimulates the release of dopamine, the feel-good hormone, meaning that eating sweets can make you feel good. So, it’s normal if your body seeks this reward cycle.

Carbohydrate cravings may lead to eating sweets, which disrupts the low-carb eating plan. So, to decrease cravings, you can consume more fatty foods like avocados, olive oil, and nuts to feel less hungry.

Drinking enough water can also increase satiety, as sometimes carbohydrate cravings are misinterpreted as hunger when you're actually dehydrated and need water.

You also need to push yourself at the beginning to resist the cravings. You should steer clear of carbohydrate-rich snacks or replace them with low-carb, protein-rich snacks like cheese, boiled eggs, or nuts.

But remember to keep the macros balanced because too much protein can also cause issues.

The Issue of Too Much Protein

While protein is an essential macronutrient on a Low-Carb Diet, overconsuming it can get you out of ketosis and disrupt the results.

When you consume too much protein, gluconeogenesis occurs, i.e., the body transforms extra protein into glucose, increasing blood sugar levels and disrupting ketosis, which can also delay weight loss.

So, it’s vital to balance macronutrients and consume enough protein. Generally, about 20-30% of your daily caloric intake can come from high-quality protein sources.

Consuming more fat, such as butter, olive oil, coconut oil, avocados, and fatty cuts of meat, can help balance protein intake.

You can use apps like GoCarnivore or this Free Macro Calculator to determine the proper amount of protein intake based on your body’s needs and goals.

Also, if your weight loss slows down due to overeating protein or any other reason, you can take the following measures to get back on track.

How to Get Back on Track When Your Weight Loss Slows Down?

Weight loss is a process with many ups and downs, and it’s normal to have periods of stalls or plateaus in weight loss. So, don’t worry, and use the following strategies. 

1. Reassess Your Caloric Intake

By losing weight, your body needs fewer calories to work properly. So, you should consume fewer calories than before. Tracking your caloric intake can help you maintain a caloric deficit.

Modifying your caloric intake based on your current weight and activity level and decreasing even 100-200 calories can restart weight loss.

2. Monitor Portion Sizes

To avoid unintentional overeating, measure your portion sizes and beware of high-calorie foods like nuts, cheese, and oils. You don’t need to count calories; you just have a general idea of high-calorie and low-calorie foods.

Also, keep a close eye on what you eat to avoid too much snacking. Providing a detailed meal plan and sticking to it can help you manage all this.

3. Focus on Whole Foods and Cut Processed Low-Carb Foods

Low-carb processed foods like bars and snacks can contain hidden carbohydrates, artificial ingredients, or extra calories. So, it’s wise to consume whole, unprocessed foods like lean proteins, vegetables, and healthy fats.

4. Track Your Macros

Balancing macronutrients is the most important point to consider in a Low-Carb Diet, as imbalances can lead to different problems like gluconeogenesis.

Although you can use tools like this Free Macro Calculator or the GoCarnivore app to keep your macros balanced, as a general rule, consume high fat, moderate protein, and low carbohydrates.

5. Increase Physical Activity

Regular physical activity can always help weight loss by increasing metabolism and burning calories. Strength training, walking, running, swimming, cycling, and High-Intensity Interval Training (HIIT) can increase fat burning and metabolic function.

6. Vary Your Workouts

Repeating the same exercise can cause a plateau as the body adapts, becomes more efficient, and burns fewer calories over time.

So, try new exercise routines or change their intensity or duration. You can also try different activities like yoga, pilates, or cycling.

7. Sleep Well and Manage Stress

Poor sleep and high stress increase hunger hormones like ghrelin and promote fat storage, hindering weight loss. So, get enough sleep (7-9 hrs) and manage stress by meditation, deep breathing, or yoga.

8. Stay Hydrated

Dehydration can slow metabolism and cause water retention, hindering weight loss. So, drink plenty of water, herbal teas, and black coffee every day and avoid sugary drinks.

9. Try Intermittent Fasting

Intermittent fasting can help you accelerate weight loss and break a plateau. Common fasting methods, like 16:8, can help increase insulin sensitivity, boost fat burning, and speed up metabolism.

10. Take Vitamin P and Consult a Healthcare Professional

Weight loss is a process, not an overnight incident, so take vitamin P (be patient) and stick to the diet. Also, consulting a healthcare professional can give you a better view of your progress and expectations.

Fixing underlying health conditions, such as thyroid issues, hormonal imbalances, or insulin resistance, can positively impact your weight loss efforts.

Conclusion

Luckily, the Low-Carb Diet side effects are temporary and will be eliminated gradually as your body gets used to the low-carb eating style.

You just need to be patient and persistent, stick to the diet, and consult a healthcare professional if necessary to ensure everything is moving smoothly.