We’ve all been guilty of it: smugly swallowing a mouthful of greens before regurgitating platitudes such as, “Abs are made in the kitchen,” or, equally misguidedly, “It’s 90% diet.” We’ve been fed the same message for years – changing what you eat is the surest route to getting in shape for the long term.

However, no matter how you serve it, it’s nonsense. Without rebooting both your training and your diet together, you’ll never tip the scales in your favour.

Researchers at the Fred Hutchinson Cancer Research Center in Seattle confirmed this when they conducted randomised trials on overweight participants: a clean diet alone was nowhere near as effective for fat loss as combining good nutrition with exercise. What’s more, our obsession with food consumption could be distracting us from more urgent statistics. A 2009 study suggested that poor cardiorespiratory fitness was responsible for nearly 17% of male deaths, while obesity accounted for just 3%, once activity levels were factored out . In short, you’d better get moving.

People may counter that, while a regular fitness habit is laudable, you can still achieve rapid changes in body composition through your diet. If eliminating carbs helps you shed your spare tyre in two weeks, you’ll be motivated to commit to a healthier lifestyle, right? Wrong.

After five years, as many as 95% of dieters will be back where they started, and 41% will have regained more weight than they lost. One study even found that subjecting yourself to a so-called weight-loss diet just once doubles your odds of becoming overweight in the future.