You’re probably generally familiar with the keto diet; you drastically reduce carbohydrate consumption, replacing carbs with high-quality healthy fats. Eliminating high-carb foods like sugars and starches (including bread, pasta, soda and most snacks) usually leads to noticeable and rapid weight loss.

But why?

Here’s the quick summary. The body turns the carbs we eat into glucose, or blood sugar. It then uses glucose as its primary energy source. Any excess glucose is stored – much of it as fat.

When the body doesn’t get enough carbs, it can’t produce enough glucose to power the body and brain. In emergency mode, it needs to find another source of energy; what it does is enter a metabolic state known as ketosis, in which it produces molecules called ketone bodies (or ketones, for short). The body – and the brain, in particular – can function very well on ketones instead of glucose.

There’s an added benefit: in order to produce ketones, the body burns its stored fat. And as everyone knows, burning stored fat means weight loss.

The bottom line is easy to figure out. As long as the body doesn’t get enough carbs to let it make glucose, it stays in ketosis and the weight loss ideally continues.

Hopefully, this short discussion of the keto diet and ketones rang a bell. Remember? MCT oil causes the body to produce ketones, too. So when it’s crucial to stay in ketosis, MCT oil can be a powerful ally for keto dieters. It helps them stay in ketosis.

Coconut oil causes the production of ketones, too – but to a much lesser extent. That makes MCT oil a better choice for that purpose.

However, coconut oil provides one advantage that MCT oil doesn’t.

A fatty acid that’s prevalent in coconut oil, but usually not contained in MCT oil, is lauric acid. It’s literally a medium-chain triglyceride but it acts more like an LCT; it’s digested and metabolized much more slowly than other MCTs. There’s an upside, though. Because lauric acid takes longer to digest, and it helps reduce production of the “hunger hormone” ghrelin, it makes you feel full and reduces your appetite. That’s a benefit that MCTs can’t provide.

Bottom line: you can use coconut oil instead of MCT oil when you’re on keto, but it won’t deliver the same effect on your ability to stay in ketosis. If you’re very careful with how many carbs you eat – and don’t need the extra help – coconut oil helps you eat less and could be a better choice.

Some who are on the keto diet add MCT oil or coconut oil directly to their food and drinks, since it can easily be added to smoothies or dressings, or included in recipes. Others take it “straight” as a supplement.

But the most popular use for MCT oil (and sometimes, coconut oil) is in so-called bulletproof coffee.

Statistics show that most people enjoy a morning cup of coffee to start their day. Whether it’s in fresh-brewed coffee, instant coffee, or iced coffee in the summer, caffeine wakes you up by boosting your energy levels. It kick-starts brain function as well. Caffeine also provides a number of other health benefits; studies show that, in moderation, coffee appears to helps with everything from cardiovascular health to diabetes prevention.

That morning coffee is also a perfect vehicle for delivering a shot of MCT oil when you’re on keto. And MCT oil is one of the ingredients in a bulletproof cup of joe. (You can put coconut oil in there, if you prefer.)

There’s another important ingredient. Most keto coffee recipes call for the addition of some grass-fed butter (unsalted butter is preferable) or ghee (a form of clarified butter). It’s used for two reasons. First, it adds great consistency and some taste to coffee. More importantly, it’s a great source of dietary fat – since keto isn’t just a low-carb diet, it’s also a high-fat one.

All sorts of other low-carb “extras” can be added to bulletproof coffee to give it more taste or to make it sweeter: keto-friendly creamer, a zero-carb sweetener like monk fruit extract or stevia, even cocoa powder or vanilla extract. But the key ingredients are simply hot coffee, butter and MCT oil (or coconut oil). 

It always helps to have a recipe the first time you make something new, so keto coffee drinkers may appreciate a little guidance. Here’s the “official” bulletproof coffee recipe; the man behind it didn’t invent butter coffee, but he certainly popularized it as much as anyone.

If you plan to make coconut oil coffee, just make the appropriate substitution in the recipe. Two cautions, though. First, coconut milk is low-carb and tastes good, but using coconut milk instead of coconut oil won’t provide the same keto benefits. Second, if you’re going to use coconut oil, use virgin coconut oil. It hasn’t been refined or treated in any way, so all of its benefits remain.

1. Combine a cup of hot coffee (8-12 ounces) with 1-2 tablespoons of grass-fed, unsalted butter (or 1-2 teaspoons of grass-fed ghee), and 1-2 teaspoons of MCT oil or coconut oil. 
2. Blend for 30 seconds, until the consistency is thick and creamy (like a latte). If you don’t have a blender, you can use a milk frother (cheap ones are available on Amazon) or a whisk instead.

Easy-peasy for most coffee drinkers, even if they don’t have the time to grind their own coffee beans. But what if you don’t have the time to do more than just pour a cup from your automatic coffee maker before rushing to work?

In that case, you might want to try a read-to-drink keto-friendly coffee like Super Coffee. It already contains MCT oil, along with added protein and zero-carb monk fruit sweetener. It comes in a number of delicious flavors and varieties. And it provides almost all the benefits of coconut oil or bulletproof coffee – without the high levels of calories and saturated fat that butter adds to the mix.

Speaking of which…

It can be, as long as you don’t drink too much of it. The Mayo Clinic says that more than 4-5 cups of any type of coffee contain so much caffeine that you could end up with the shakes, jitters or worse. Less than that is fine, for healthy adults.

The real problem, though, comes when you make traditional bulletproof coffee – even if you use coconut oil instead of MCT oil. The culprit? Butter or ghee, which contain a ton of calories and saturated fat. In fact, if you use two tablespoons of butter in your coconut oil coffee, you’ll be consuming more saturated fat than the American Heart Association recommends as a daily maximum.

And that’s just the saturated fat in one cup of keto coffee. If you eat more during the day, the potential health issues are even worse.

Speaking of which, there are two other landmines to avoid. Many keto dieters like bulletproof coffee so much that they drink several cups of it during the day; that makes the saturated fat and calorie issues even worse. And some drink it as a substitute for breakfast, because it’s very filling. Unfortunately, there are no important nutrients in keto coffee; and eliminating a healthy breakfast also eliminates the vitamins, nutrients and protein the body needs.

Stick with coconut oil coffee that doesn’t include butter – or be very careful with how much you drink – and it’s likely you’ll be satisfied with the taste and the results.