Butter coffee has quickly become a trendy drink among those following low carb diets, often touted as helping increase energy, mental clarity, promote weight loss and lower cholesterol. But is it actually healthy?

Fat and coffee go together since time immemorial; butter has long been combined into beverages as part of daily life in many parts of the world. But it didn’t become a lifestyle beverage until entrepreneur and lifestyle author Dave Asprey began sharing his butter coffee recipe in late 2000s, taking inspiration from rural Tibetan people drinking yak butter tea at high altitudes for inspiration. Dave’s version, known as Bulletproof coffee, became increasingly popular with fitness enthusiasts as well as those following low-carb, high-fat (LCHF) diets.

His drink features coffee, grass-fed butter and MCT oil (medium-chain triglycerides). Grass-fed butter provides more nutrition than conventional milk-based butter due to higher omega-3 fatty acid and anti-inflammatory conjugated linoleic acid levels; while MCT oil may aid cardiovascular health while preventing diabetes and aiding weight loss.

Asprey claims that combining these ingredients helps improve caffeine absorption by slowing digestion, creating a steady energy release without an unexpected glucose crash. He further claims it increases satiety and may help curb cravings.

But he neglects to mention that both MCT oil and butter used to prepare his drink contain high levels of saturated fats – while these types of fatty acids aren’t considered harmful in themselves, too much could negatively impact cholesterol and cardiovascular health.

Butter coffee contains many extra calories than anticipated; an average serving contains 26g of fat (12g from butter and 14g from MCT oil). Furthermore, there’s plenty of added sugar which could derail many diets.

If you choose to experiment with butter coffee, be sure to limit yourself to smaller serving sizes and include other sources of high-quality fats, ideally from plants rather than animals. Too much saturated fat without sufficient unsaturated fat can increase cholesterol and cause heart disease; for this reason it is wise to discuss this beverage with your physician first before adding it into your routine. In addition, regular check-ups on cholesterol may be advisable. If any symptoms arise such as high cholesterol or heart conditions that require low-fat diets with your physician.