You’ve tried and tested every diet under the sun while spending hours on a treadmill.

So why isn't it working out for you? New research from Harvard University has proven the best way to tame that tummy – and it has nothing to do with cutting carbs or doing cardio. So what’s the most effective way to blast that belly fat? Well, there’s a reason the weights section of the gym is always so busy… According to a new study published in medical journal Obesity, spending time in the weights section can significantly help you break down that belly fat. Researchers followed more than 10,500 men aged 40 years or more over a 12 year period. Documenting their personal weight and cardio workouts, the study found that those who added 20 minutes of weight training to their regular cardio workout gained less fat around the middle than those who purely hit the treadmill. The researchers concluded that working with weights not only burns fat and builds muscle – it also helps kickstart your metabolism. Lead author of the study Rania Mekary, PhD explained: "Engaging in resistance training or, ideally, combining it with aerobic exercise, could help older adults lessen abdominal fat while increasing or preserving muscle mass.” So if you’re struggling to see some real results from your January effort, it might be time to start concentrating on some simple free weights.