Investigating the Effects of Bulletproof Coffee on Cognitive Function and Satiety

Introduction

Bulletproof Coffee, a high-fat coffee beverage made with medium-chain triglyceride (MCT) oil and grass-fed ghee, has gained popularity in biohacking and wellness communities. It is frequently marketed as a tool to enhance cognitive function, promote mental clarity, and suppress appetite, particularly among followers of ketogenic diets and intermittent fasting protocols.

Despite its growing popularity, the scientific evidence supporting these claims remains limited. This study aimed to assess whether consuming Bulletproof Coffee results in measurable improvements in cognitive performance and subjective measures of satiety compared to traditional black coffee.

Study Design

The researchers conducted a single-blind, randomized, counterbalanced crossover trial. Six healthy, regular coffee-consuming adults (five females, average age 25) participated in two testing sessions spaced approximately one week apart.

In each session, participants arrived in a fasted state and completed baseline assessments before consuming one of the following beverages:

• Bulletproof Coffee: 10 oz brewed coffee blended with 15 ml MCT oil and 15 ml grass-fed ghee (approximately 250 kcal)
• Black Coffee: 10 oz brewed coffee (approximately 1 kcal)

Following beverage consumption, participants completed the same set of tests at 60 and 170 minutes post-ingestion. While researchers were blinded to the beverage consumed, participant blinding was not feasible due to distinct taste and texture differences.

Measurements

Cognitive function was assessed using tablet-based tasks, including:

• Digit Symbol Substitution Task (DSST)
• Stroop Task
• Speed Task

Additional subjective measures included:

• Hunger and fullness ratings
• Prospective food consumption
• Cognitive arousal
• Gastrointestinal discomfort

Findings

Cognitive Function
The data revealed no significant differences in cognitive performance between the two beverages. Specifically, results from the DSST showed no improvement with Bulletproof Coffee relative to black coffee (P = 0.44). Performance on the Stroop and Speed Tasks showed similar non-significant results. This suggests that, in the short term, Bulletproof Coffee does not provide additional cognitive benefits beyond those of regular black coffee.

Satiety and Appetite
In contrast, differences emerged in satiety-related outcomes. Participants who consumed Bulletproof Coffee reported:

• Significantly higher feelings of fullness throughout the trial (P = 0.04)
• A notable reduction in perceived prospective food consumption (P = 0.02)

These results indicate that the caloric content and fat composition of Bulletproof Coffee may effectively increase satiety and reduce short-term appetite compared to black coffee alone.

Conclusion

This preliminary study suggests that while Bulletproof Coffee does not enhance cognitive function more than black coffee, it may play a role in appetite regulation by increasing fullness and reducing the desire to eat over a three-hour period. Although the sample size was limited and results are considered exploratory, these findings contribute to the growing interest in how high-fat beverages influence satiety and dietary behavior.

Further research with larger cohorts and longer-term follow-up is needed to fully understand the implications of high-fat coffee consumption on cognition, metabolism, and dietary habits.

Source:

PubMed Central – PMC8181361 (https://pmc.ncbi.nlm.nih.gov/articles/PMC8181361/).