Many people swear by butter coffee, claiming that it provides lasting energy, boosts mental clarity, and supports fat loss by suppressing hunger.

Also, while there’s no evidence to suggest that butter coffee can help you reach a state of ketosis quicker, it can provide additional fuel in the form of ketones for those in ketosis. Still, it may not raise your blood ketone levels any more than eating MCT oil alone.

Although no studies have directly examined the potential health benefits or risks of the beverage, it is possible to make assumptions based on current research.

Hunger

Proponents of butter coffee claim that it suppresses hunger and helps you lose weight by helping you eat less.

Butter coffee contains a large amount of fat, which slows digestion and may increase feelings of fullness (7, 8, 9, 10).

Specifically, the coconut oil in butter coffee is a rich source of MCTs, a type of fat that may promote feelings of fullness more than the long-chain triglycerides (LCTs) found in other high-fat foods like oils, nuts, and meat (11).

For example, one study found that men who ate a breakfast containing 22 grams of MCT oil for 4 weeks consumed 220 fewer calories at lunch and lost more body fat than men who ate a breakfast high in LCTs (12).

Studies have also reported reduced hunger and greater weight loss in people following low-calorie diets with the addition of MCTs, compared to the addition of LCTs. However, these effects appear to diminish over time (13, 14, 15).

Adding MCTs to a reduced-calorie diet may improve feelings of fullness and promote short-term weight loss when used in place of LCTs. Yet, there’s no evidence that just adding MCTs to your diet without making other dietary changes will promote weight loss (16).

Energy

Butter coffee is believed to provide steady, long-lasting energy without a blood sugar crash. In theory, since fat slows digestion, the caffeine in the coffee is absorbed slower and provides longer-lasting energy.

While it’s possible that the fat from butter coffee may slow the absorption and prolong the effects of caffeine, the effect is likely insignificant and unnoticeable (17).

Rather, the MCT oil is likely responsible for the purported long-term, energy-boosting effects of butter coffee. Given their shorter chain length, MCTs are rapidly broken down and absorbed by your body (18).

This means they can be used as an instant energy source or turned into ketones, which are molecules produced by your liver from fatty acids that can help boost energy levels over a longer period.

Mental clarity

Butter coffee is said to boost mental clarity and improve cognitive function.

If you’re following a keto diet, your liver converts MCTs into ketones. These ketones are a key source of energy for your brain cells (19).

Although the utilization of ketones by your brain has been shown to benefit some neurodegenerative diseases like Alzheimer’s and Parkinson’s, there’s no evidence to suggest that MCTs as a source of ketones enhances mental clarity (20, 21).

Rather, there’s evidence to suggest that the caffeine in coffee is what’s responsible for the purported boost in mental focus and alertness experienced after drinking butter coffee (22, 23, 24, 25).

Summary

The MCTs in butter coffee may help promote fullness and aid weight loss when used with a calorie-restricted diet. Also, the caffeine and MCTs in butter coffee may help boost your energy and focus. That said, more research is needed.