Many of us no doubt subscribe to the 'go for a run so I can have guilt-free pasta and beer for dinner' philosophy. I know I certainly do. But experts are now saying it's a myth that you can outrun a bad diet.

According to a recent editorial by three researchers specialising in human biology, while physical activity can stave off the effects of several common and debilitating diseases, when it comes to weight loss, the devil is in the diet. "A recent report from the UK's Academy of Medical Royal Colleges described 'the miracle cure' of performing 30 min of moderate exercise, five times a week, as more powerful than many drugs administered for chronic disease prevention and management," they write. "Regular physical activity reduces the risk of developing cardiovascular disease, type 2 diabetes, dementia and some cancers by at least 30 percent. However, physical activity does not promote weight loss."

Publishing in The British Journal of Sports Medicine, Aseem Malhotra from the Academy of Medical Royal Colleges in the UK, Timothy Noakes from the University of Cape Town and the Sports Science Institute of South Africa, and Stephen Phinney from the University of California Davis School of Medicine in the US say our calorie-laden diets are responsible for more ill health in around the world than physical inactivity, alcohol, and smoking combined.

They also argue that public misperception is due to dodgy corporate marketing, describing the "public relations tactics of the food industry as 'chillingly similar to those of Big Tobacco,' which deployed denial, doubt, confusion and 'bent scientists' to convince the public that smoking was not linked to lung cancer."

Malhotra, Noakes, and Phinney say the link between junk food and sports must end, such as when beer companies sponsor big sporting matches or McDonalds and Milo sponsor children's sport camps. While "regular exercise is key to staving off serious disease, such as diabetes, heart disease, and dementia," the 40 percent of us that fall within a normal weight range (per BMI) will nonetheless harbour harmful metabolic abnormalities typically associated with obesity, they report.

Another misstep is the push towards calorie-counting. It's the source of the calories that matters, the trio writes: "Sugar calories promote fat storage and hunger. Fat calories induce fullness or satiation." As evidence, they point out that 150 extra sugar calories per day increases the chance of getting diabetes 11 times more than the equivalent amount of fat-calories.

And carbs are no better, with recent research suggesting cutting them out is the number one strategy for reducing metabolism problems and treating diabetes.  In fact, some researchers suggest fat-loading rather than carb-loading before intense exercise.

"The food environment needs to be changed so that people automatically make healthy choices," suggest the authors. "Healthy choice must become the easy choice."

So while yoga might be all well and good, in the end, you've still gotta ditch the chips.