Bulletproof coffee is a high-calorie coffee drink intended to replace breakfast.

It consists of 2 cups (470 ml) of coffee, 2 tablespoons (28 grams) of grass-fed, unsalted butter, and 1–2 tablespoons (15–30 ml) of MCT oil mixed in a blender.

It was originally promoted by Dave Asprey, the creator of the Bulletproof Diet. The coffee produced and marketed by Asprey’s company is supposedly free of mycotoxins. However, there’s no evidence that this is the case.

Bulletproof coffee has become increasingly popular — especially among paleo or low-carb dieters.

Although drinking Bulletproof coffee on occasion is probably harmless, it’s not advisable to make it a routine.

Here are 3 potential downsides of Bulletproof coffee.

Why Bulletproof Coffee is a Bad IdeaShare on Pinterest

Asprey and other promoters recommend that you consume Bulletproof coffee instead of breakfast each morning.

Although Bulletproof coffee provides plenty of fat — which reduces your appetite and gives you energy — it’s lacking in several nutrients.

By drinking Bulletproof coffee, you are effectively replacing a nutritious meal with a poor substitute.

While grass-fed butter contains some CLA, butyrate, and vitamins A and K2, MCT oil is a refined and processed fat with virtually no essential nutrients.

If you eat three meals per day, replacing breakfast with Bulletproof coffee will likely reduce your total nutrient load by about a third.

SUMMARY Promoters of Bulletproof coffee recommend that you drink it instead of eating breakfast. However, doing so will significantly reduce the total nutrient load of your diet.

Bulletproof coffee is very high in saturated fat.

While the health effects of saturated fats are controversial, many health professionals believe that high intake is a major risk factor for several diseases and should be avoided ().

Although some studies associate a high intake of saturated fat with an increased risk of heart disease, others find no significant links ().

Nevertheless, most official dietary guidelines and health authorities advise people to limit their intake.

Although saturated fat can be a part of a healthy diet when consumed in reasonable amounts, it may be harmful in massive doses.

If you are worried about saturated fat or high cholesterol levels, consider limiting your intake of Bulletproof coffee — or avoiding it altogether.

SUMMARY Bulletproof coffee is high in saturated fat. Although its health effects are highly controversial and not firmly established, official guidelines still recommend limiting saturated fat intake.

Many studies have been conducted on low-carb and ketogenic diets, which are often high in fat — and may include Bulletproof coffee.

Most of this research confirms that these diets do not increase your levels of total and LDL (bad) cholesterol — at least on average (3).

Among other benefits, your triglycerides and weight drop while your HDL (good) cholesterol goes up ().

But not everyone responds the same way to a high-fat diet. Some people see dramatic increases in total and LDL (bad) cholesterol, as well as other markers of heart disease risk ().

For those who have cholesterol problems while on a low-carb or ketogenic diet, the first thing to do is to avoid excessive saturated fat intake. This includes Bulletproof coffee.

SUMMARY Ketogenic diets high in saturated fat may increase cholesterol levels and other heart disease risk factors in some people. For those who have elevated levels, it’s best to avoid Bulletproof coffee.

All things considered, Bulletproof coffee can work for some people — especially those following a ketogenic diet who don’t have elevated cholesterol levels.

When consumed alongside a healthy diet, Bulletproof coffee may help you lose weight and increase your energy levels.

If you find that this morning drink improves your well-being and quality of life, perhaps it’s worth the decreased nutrient load.

Just to be on the safe side, anyone who drinks Bulletproof coffee regularly should have their blood markers measured to make sure you’re not raising your risk of heart disease and other conditions.

SUMMARY Bulletproof coffee may be perfectly healthy for some individuals, as long as you consume it as part of a balanced diet and don’t have elevated cholesterol levels. It may be especially appealing for those on keto diets.

Bulletproof coffee is a high-fat coffee drink intended as a breakfast replacement. It’s popular with people who follow a ketogenic diet.

While it’s filling and energy-inducing, it comes with several potential downsides — including reduced overall nutrient intake, increased cholesterol, and high levels of saturated fat.

Still, Bulletproof coffee may be perfectly safe for those who don’t have elevated cholesterol levels, as well as those who follow a low-carb or ketogenic diet.

If you’re interested in trying Bulletproof coffee, it may be best to consult with your healthcare provider to get your blood markers checked.