Coffee drinkers have less body fat and more muscle, study finds

A study conducted at the University of Oulu in Finland investigated the relationship between coffee consumption and body composition. Researchers analyzed data from more than 2,200 participants who completed questionnaires about their health, diet, physical activity, medications, diagnosed conditions, and lifestyle habits, including daily coffee intake. The amount of coffee consumed ranged from none to at least five cups per day. The study did not include details on cup size, brewing methods, or additions like milk, sugar, or flavorings.

After an overnight fast and avoiding coffee, the team measured body fat and muscle mass, collected blood samples, and administered a glucose drink to assess how participants' bodies handled sugar over two hours. The results showed that individuals who drank more coffee had greater skeletal muscle mass, lower total body fat, and less visceral fat—the abdominal fat around internal organs that is closely linked to cardiovascular disease and other health issues.

However, the study does not prove that coffee directly reduces fat or builds muscle. The researchers found that higher coffee intake was associated with lower levels of three branched-chain amino acids (BCAAs)—leucine, isoleucine, and valine—which are protein building blocks. Chronically high levels of these amino acids are strongly linked to insulin resistance and a higher risk of diabetes. While lower BCAA levels may indicate a healthier metabolic pattern, the study did not show that coffee specifically lowered these amino acids.

Interestingly, the effects varied by sex. Men who drank more coffee had higher levels of some cholesterol-carrying lipoprotein particles and lower omega-3 fat levels, which are less favorable outcomes. Men also tended to have lower fasting insulin and lower insulin levels, while women showed fewer and weaker links between coffee and glucose control. Lead author Luca Verroest noted that despite coffee being consumed by millions daily, surprisingly little is known about its effects on metabolism and hormones.