From baby shower banter to podcast episodes, we’ve been hearing about the ‘Bulletproof Coffee’ trend everywhere. We’ve heard our fair share of anecdotes touting health benefits from the strange breakfast substitute. Because everyone out there is Googling it, we figured we would dig into the science.

First, let’s take a look at what ‘bulletproof coffee’ is supposed to mean.  You’re supposed to replace your breakfast with:

• 2 cups of coffee
• 2 tablespoons of grass fed, unsalted butter
• 1-2 tablespoons of medium chain triglyceride (MCT) oil, such as coconut oil

Dave Asprey isn’t a trained expert in nutrition or health physiology. But somehow, he’s created a nutrition empire that centers on bulletproof coffee to ‘supercharge your brain function and create effortless fat loss with no cravings.’ Are these claims supported? Does replacing breakfast with ‘bulletproof coffee’ offer nutritional benefits? (If you’d like the short version: No.)

A ‘bulletproof coffee’ delivers about 441 calories, 51 grams of fat (80% of which are saturated fat, which dietary guidance says to limit), and not much else. Bulletproof coffee also comes with 0 grams of carbs or fiber and a lowly 1 gram of protein. It’s completely devoid of many important vitamins and minerals.

Because breakfast is an opportunity to consume healthful nutrients like protein, fiber, and vitamins, substituting ‘bulletproof coffee’ for it reduces the potential nutrient intake. Scientific studies support the importance of starting the day with a healthful breakfast. Multiple reports have shown that a nutritious breakfast can prevent long-term weight gain and obesity.

While some people have reported weight loss on the ‘bulletproof diet,’ that likely has to do with how they’re already eating. Many of those reporting weight loss are already on a ketogenic diet, basically eating a low-carb and high-fat diet. This makes them ‘keto-adapted.’ That means those who take in few carbs for energy get their energy from fats, which their liver converts into fatty acids and ‘ketone bodies.’ These ketone bodies replace glucose as an energy source.

A ketogenic diet is only a short-term solution for weight loss. Most of the dropped weight is due to loss of water, as dehydration is a common side effect of this diet. Avoiding carbohydrates is not a feasible, long-term strategy for healthful eating, because carbohydrates offer essential health benefits like fiber and energy.

Although there are reported uses and anecdotal claims stemming from bulletproof coffee, there have been no clinical studies investigating its health effects. On the down side, some scientific case studies have shown that hyperlipidemia—basically, high cholesterol—is elevated in otherwise healthy patients. At the American Association of Clinical Endocrinologist meeting in 2014, Dr. Karl Nadolsky presented the case study of a 39-year-old patient who incorporated ‘bulletproof coffee’ into his daily routine. The patient had a 34-point increase in total cholesterol and was at a high-risk level for health problems. Dr. Nadolsky attributed these negative effects to the bulletproof coffee intake, saying that people are simply “getting extra calories … and giving themselves a bomb of no-so-great long chain saturated fatty acids.”

So yes, there’s a total lack of nutritional value or any scientific support for the ‘bulletproof coffee’ fad. Instead of focusing on the next best thing in food and nutrition, choosing diets that are well-balanced and nutritious are the only bulletproof way to achieve long-term and sustainable healthful eating.