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Is Coffee OK on the Keto Diet: Caffeine and Metabolism

Is Coffee OK on the Keto Diet: Caffeine and Metabolism

by Olivia Bradford -

Caffeine is commonly present in most people's morning routines. And with coffee being the third most consumed beverage in the world, only preceded by water and tea, respectively, your morning cup of java is likely the source of your AM caffeinated wake-me-up to help you get the day started.

But aside from adding a little pep to your morning routine, caffeine has a stimulant effect on the body that is known to trigger a fat-burning effect as well! Yet, it may also spike hormones like adrenaline, and cortisol, which encourages the body to burn carbs and sugars rather than fat and ketones as a primary source of fuel—the opposite of our goal on a ketogenic diet.

So, you may wonder whether drinking coffee will contribute to increased energy and stamina and offer a slight fat-burning advantage or if the stimulant's effect on your metabolic hormones will inform your cells to store rather than release fat. Both are valid considerations.

The good news is that you can keep your k-cup brewers and French-presses because you can still drink coffee and other caffeinated drinks on keto! Plus, the flavored syrups available containing keto-friendly sweeteners expand your creative options, enabling you to make an endless variety of tasty concoctions.

However, there are some points to keep in mind when sipping your beloved morning brew to curb the carbs. And you can even boost your cup of java with potent ingredients like MCT oil to add even more of a super-charged jolt to your daily brew!

Caffeine, Coffee, and Metabolism

Caffeine is a stimulant; it's why it gives us that buzz we all crave! But caffeine provides other effects in addition to helping to get you going before breakfast.

Fascinating preliminary studies reveal an increased thermogenic effect post-meal when coffee is consumed immediately before or with food, enhancing the body's fat-burning efficiency for hours after you eat.

Plus, fat oxidation in the body is significantly greater after drinking coffee. Meaning, the body breaks down more significant amounts of fatty acids after drinking your favorite flavorful caffeinated drink!

Coffee has received mixed reviews over the years about whether it's good or bad for us. However, a study conducted by the Mayo Clinic found that the process of thermogenesis stimulated by caffeine when consumed appears to increase energy output, which helps the body burn more calories, even when at rest.

Appetite Control

Elevated ketone levels in the body thanks to ketosis are a fantastic appetite suppressant. However, swigging java can harness your appetite a touch, even if it’s partially because the fluid is filling you up.

Couple the appetite suppression experienced in metabolic ketosis with the slight short-term appetite curbing caused by caffeine as a tool at times of the day when you’re often susceptible to giving into food cravings to make caffeine work for you.

Plus, coffee can overexcite the digestive tract and may stimulate spasms in the bowel that cause mild bloating—making you feel fuller temporarily, although caffeine itself doesn’t directly suppress ones’ appetite.

Drinking caffeinated coffee may reduce levels of the hunger hormone ghrelin, and some studies have shown subject groups observed consuming coffee ate fewer calories overall.

Still, as we mentioned, the jury is still out on whether caffeine and coffee have a definitive appetite suppressing effect. But if you are a coffee lover and find drinking coffee reduces your tendency to snack excessively, use that as yet another of many reasons to love coffee.

Increased Energy Output with Caffeine Consumption

Coffee, tea, and other caffeinated beverages are favorites for their taste but those who drink them daily likely do so for their energy-boosting abilities as well. Whether you grab a hot or cold-brewed coffee to begin your day, unwind in the afternoon with a warm cup of tea, or enjoy an electrolyte-rich chilled beverage pre-workout, the added caffeine can provide a noticeable kick to power your workout.

Drinking caffeinated coffee may lessen levels of the hunger hormone ghrelin, which may contribute to reduced hunger after sipping your morning brew. The ghrelin present may inform your brain that your body is full sooner, creating feelings of satiety and lessening chances of overeating.

Plus, popping a potent energy shot charged with caffeine is a method used by some before workouts to give them a little extra edge to help conquer new and exciting personal records. Consider ‘zero’ lines of energy drinks for a low-carb option, or opt for a little coconut water for some added electrolytes and hydration.

But be sure to go slowly with caffeine because a little can be great but a lot may lead to increased levels of anxiousness, and jitters, along with potentially causing sleep disruptions and problems concentrating.

Caffeine and Type 2 Diabetes

Caffeine affects everyone differently, but this is especially true for those with type 2 diabetes. Increasing bodies of research suggest people with type 2 diabetes respond to caffeine differently.

Instead of just the desirable perk-me-up of your caffeinated beverage, those with type 2 diabetes can experience raised blood sugar and insulin levels, as well.

Plus, consuming caffeine with meals can boost insulin levels post-meal and lead to diabetes complications, which may lead to a higher risk of heart damage or heart disease.

The complete outlook regarding the effects of caffeine on insulin are a topic of interest to researchers who continue to glean more knowledge of the nuance of the matter with further review, but the current information available appears to lean toward the following:

  • Caffeine increases specific stress hormones like adrenaline (also called epinephrine) in the body, which may prevent your body from assimilating as much sugar, which may keep your body from making as much insulin.
  • Caffeine also inhibits a protein molecule called adenosine, an element that plays a significant role in the amount of insulin the body makes—as well as how the body’s cells respond to it.
  • While you may welcome the added energy in the earlier part of the day to power you through your jam-packed to-do list; the pep provided by the ingredient can prove problematic in the evening, causing sleep disruptions.

There’s a good reason why college students and entrepreneurs alike rely on coffee and caffeine; it keeps you awake! And in addition to diminishing quality or duration of sleep, an added side effect of a lack of sleep may be the lowering of your insulin sensitivity.

As little as 200 mg of caffeine can impact your blood sugar, which is about the amount you’ll consume in up to two cups of coffee or four cups of black tea.

Remember, factors like age and weight, along with pre-existing metabolic conditions like type 2 diabetes can affect your body’s reaction to caffeine. It’s best to proceed with caution and check your blood sugar after consuming caffeine with food to determine how it impacts your blood sugar levels.

Coffee Could Be Toxic

Excessive levels of coffee, like most things, can cause toxicity where the body cannot properly process the amount consumed. But don’t become too alarmed, you’d have to drink about 80 cups of coffee in 24 hours to experience caffeine poisoning, which would provide approximately 1,000 mg of pure stimulant. Although possible, it’s quite a feat to achieve.

Coffee and Vitamin Deficiency

Caffeine disrupts the body’s absorption of magnesium and iron, with low levels of magnesium associated with an increased potential of weight gain. Plus, ketosis encourages the body to flush essential electrolytes like magnesium at higher rates, requiring us to replenish them more frequently when eating a low-carb, high-fat diet.

As we promised at the onset, we’re not banishing coffee or caffeine from the list of coveted staples in your keto pantry. Our goal is to guide you to enjoy your coffee responsibly to avoid the adverse effects of overdoing the consumption of caffeinated beverages.

Most things in life are as much about how you do them as that you do them in the first place. And a few simple considerations will help to enjoy your java and other energy drinks while keeping your nerves, hormones, and appetite in check.

  • Stop after your first cup, or two, and see how you feel before proceeding further. Also, if not a die-hard coffee drinker, consider alternating your morning beverage and swapping in tea instead for an option with less of a buzz but ample warmth and feelings of comfort.
  • Drink loads of water: Consuming large amounts of water is already crucial on keto because of the increased body fluid released in ketosis, but sipping on H2O is vital when consuming caffeine because the ingredient is a diuretic and encourages the release of more water from the body, as well.

Plus, it’s wise to remember that thirst is often interpreted as hunger. So, remaining hydrated throughout the day is beneficial on many levels, including helping you identify genuine hunger to avoid overeating.

  • Monitor Caffeine Intake: Knowing the amount of caffeine you consume is an excellent way to gauge the amount that’s comfortable for you versus what’s too much. Dietitians note that 300 mg of this stimulant a day is an acceptable amount (approximately 4oz of espresso).
  • Be Strategic About Breakfast: You may choose to fast into the afternoon on keto, but our hunger-signaling hormone, ghrelin, increases as we sleep. Coffee may be your first choice of the day, but it’s a good idea to include protein and healthy fats like avocado with breakfast to satiate hunger and energize your morning.
  • Phase Away from Caffeine Slowly: Cutting out caffeine cold turkey is an excellent way to trigger headaches and grumpy moods, and there’s no need to take an all-or-nothing approach. Step down your portions and frequency of caffeine consumption until you have levels low enough to avoid experiencing adverse effects.

Coffee withdrawal symptoms are real and tangible. Some of the most commonly experienced side effects of eliminating caffeine suddenly include:

  • Lack of concentration: People often drink caffeinated beverages like coffee or an energy drink before a tough exam as they stimulate the neurotransmitters dopamine and norepinephrine which triggers elevated heart rate and blood pressure, thereby stimulating the brain leading to heightened alertness and ability to focus. Suddenly eliminating caffeine may lead to feelings of head fog or grogginess, but this should clear up after a few days free of caffeine.
  • Irritability: Removing a stimulant makes the body work harder to achieve the same feelings of perkiness received before by simply sipping on your favorite caffeinated beverage. It may be worth including more foods with natural sources of caffeine to keep your mood stable.
  • Dizziness: Some report feelings of dizziness when eliminating coffee, so take caution when getting up suddenly or engaging in physical activity.
  • Depression: Caffeine is shown to provide a boost to our energy and mood, and eliminating it may create a lull in morreale temporarily.
  • Sleepiness/Fatigue/Low Energy: Again, caffeine is a stimulant and if we no longer have the boost of it throughout the day, we may feel a bit sluggish as a result. Consider consuming beverages like water, bone broth, and coconut water to offset the effects of eliminating caffeine suddenly.
  • Headaches: The body develops a physical reliance upon caffeine if consumed regularly and in large amounts, and removing it from the diet at once can cause withdrawals, producing unfortunate side effects such as headaches.
  • Anxiety: Too much caffeine can lead to increased anxiety, but removing the stimulant of caffeine can produce a similar effect in some people.
  • Tremors or Jitters: The look of urgency on the face of coffee lovers waiting outside Starbucks in the morning is real; the body comes to rely on caffeine physically and psychologically over time. You may notice jitters or tremors if you consume excessive amounts of caffeine or remove it completely suddenly—ease away from caffeine, if that’s your desire, or tweak your intake to determine the ideal level for your body’s tolerance.

The sudden absence of caffeine for someone who has thoroughly enjoyed consuming it for a while can be challenging. Try to gradually eliminate caffeine if this is a route you choose to take, and you may avoid the mentioned problems altogether.

Explore Natural Energy Drinks

  • Electrolyte beverages/powders: Staying hydrated and replenishing electrolytes is essential on a keto diet, as we’ve noted, and there are some sugar-free and keto-friendly options out there.
  • Matcha tea is filled with phytonutrients, which is why this Japanese tea is so effective at fighting hunger. Plus, it’s added touch of caffeine offers a gentle energy boost as well.
  • Enjoy your low-glycemic fruits for a slight dose of fructose to increase energy during the midday lull and beyond.
  • Bone broth offers many benefits including electrolytes, vitamins, minerals, and hydration, all promoting elevated energy levels and increased stamina when paired with a healthy low-carb diet and regular physical fitness.

Plus, we can include spices like cinnamon, turmeric, and red pepper into our recipes to help suppress hunger and prevent body fat storage.

Also, aside from minding caffeine intake it’s important to prepare your coffee and other caffeinated drinks wisely.

Although coffee and tea are free of carbs, the creamer and sweetener or flavorings we use can compromise our commitment to cut the carbs. So it’s imperative to select our flavorings and enhancers carefully to stay on track.

Also, remember, there are many ways to enjoy your coffee without gaining weight. Here are a few additional tips to tailor your coffee toward the guidelines of a sugar-free lifestyle:

  • Obviously, we know, but eliminate the sugar—including the hidden sugars in added syrups and other flavorings often included in some of your favorite coffee concoctions. Ask for heavy cream or another keto-friendly milk alternative in your coffee and keep a close eye on additives or bring your own and add them yourself to have full control of your selections.

Plus, here are several ways to reduce sugar intake while still jazzing up your coffee:

  • Sprinkle in some cinnamon or nutmeg.
  • Use unsweetened almond milk, coconut milk, macadamia nut milk, hemp milk, cashew milk, flaxseed milk, or heavy cream.
  • Use a small amount of stevia, erythritol, allulose, or monk fruit, along with syrup options like those made by Skinny Syrups, to add flavor and flare to your coffee without the unwanted sugar or calories.
  • Add a few drops of vanilla extract for a delicious twist on your daily brew.
  • Melt some high-quality dark chocolate into your coffee for a touch of mocha in the morning.

Also, take care to use grass-fed butter and premium MCT oil or heavy cream when making your keto coffee. While eliminating carbs is paramount, the quality of the ingredients we consume, even the keto-friendly ones, is still essential.

Plus, food plays a significant role in the way our bodies assimilate caffeine. Elements like broccoli, and other foods containing vitamin C may all intensify and prolong the effects of caffeine.

Caffeine and Pregnancy

Our bodies go through a range of changes during pregnancy, as we nurture the development of a new life. And the metabolism of caffeine is diminished, especially during the third trimester when the baby's needs continue to demand increasing vitamins and other nutrients from mom.

As a result, the time it takes for caffeine to flush from our system is delayed—possibly prolonging a gentle energy boost or a jitter jolt, depending on the amount consumed.

Caffeine and Medication Interaction

The way caffeine moves and operates throughout the body, or caffeine pharmacokinetics, may be affected when interacting with different prescribed medical drugs, so it’s important to be mindful if you have a caffeine sensitivity and are prescribed said medications.

Consult with your physician if you have a caffeine sensitivity and are taking a drug that may affect caffeine clearance, as your physician may want to adjust your medication dosage or suggested amount of caffeine consumption accordingly.


The effects of caffeine may vary based on various factors, including proper liver function, smoking status, alcohol consumption, and genetics. However, current research points to a temporary appetite suppressive effect along with short-term energy bursts as a reliable benefit of consuming caffeine to leverage around workouts or nights when you have many tasks to tackle for your work or home life.

Moderating your caffeine intake and listening to your body after drinking caffeinated drinks is the best way to gauge how the stimulant affects your body. Be mindful of increased cravings or sleep disruptions and jitters that may occur if you consume more than your body can process.

Follow the motto of low and slow. Drink lower amounts of caffeine and observe the results and take it from there, making sure to track all forms of caffeine consumed throughout the day as your morning coffee, midday energy drink, evening dark chocolate treat, and evening tea create a compounding effect throughout the day.


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