Drinking five or more cups of coffee a day could help keep dangerous belly fat at bay, reducing the risk of diabetes, heart disease and even cancer, research suggests.Finnish scientists found that those who regularly drink around five cups of coffee a day have less visceral fat and more muscle mass than lighter coffee drinkers, despite broadly weighing the same. Unlike the fat you can pinch around your waist, visceral fat surrounds the internal organs and releases harmful chemicals that can trigger disease.Dubbed a 'silent killer', visceral fat has been linked to heart disease, type 2 diabetes, Alzheimer's and a range of cancers including liver, bowel and stomach. Coffee has previously been linked to a lower risk of heart disease. But now researchers say regular consumption could lead to a healthier overall body composition.'Coffee is consumed by millions of people every day, yet we still know surprisingly little about how it relates to our metabolism,' Luca Verroest, an expert in metabolism at the University of Oulu, and the study's lead author explained. 'What stood out in our findings was a distinct pattern that didn't disappear even after we took into account body mass index (BMI) and lifestyle factors.' The study – published in the European Journal of Nutrition – analysed data from 2,264 participants aged 46 from the Northern Finland Birth Cohort 1966. People who drink at least five cups of coffee a day tend to have less visceral fat than non-drinkersParticipants were split into four groups based on how much coffee they consumed on average, ranging from none to five or more cups a day. Researchers then looked at their weight, BMI, waist size, body fat percentage, muscle mass and blood pressure. Blood samples were also taken to measure cholesterol and insulin levels, as well as track sex hormones such as testosterone.They found that those who drank the most coffee had the lowest body fat percentage – at around 27 per cent – compared to those who drank none, who sat at around 29 per cent body fat. People who drank five or more cups a day also had around six per cent less visceral fat than non-drinkers and the highest muscle mass. Interestingly, BMI – a measure of weight relative to height - was virtually the same across all groups, despite habitual coffee drinkers carrying less fat and more muscle. Higher coffee intake was also linked to lower levels of a type of amino acid that has previously been linked to obesity and type 2 diabetes. Men who drank more coffee generally had more favourable insulin levels and higher levels of total testosterone, which the researchers said could help protect against diabetes and other metabolic diseases.