Innocent lettuce? Think again. Credit:Getty Images I've always thought lettuce was a fairly virtuous vegetable. That was until lettuce's character was called into question earlier this year. One Washington Post story was entirely dedicated to sullying salad's clean image. Lettuce, the article said snarkily, was one food that "has almost nothing going for it. "It occupies precious crop acreage, requires fossil fuels to be shipped, refrigerated, around the world, and adds nothing but crunch to the plate."

To put the lack of nutrients in perspective, the article's author added: "A head of iceberg lettuce has the same water content as a bottle of Evian (1 litre size: 96 per cent water, 4 per cent bottle) and is only marginally more nutritious." Salad is also an excellent example of a "health halo" food; a food that we tend to overeat because we overestimate its health benefits. It is not its lack of nutrition that we are overestimating, in this instance, rather the additions "salad" gives us licence to include. Potatoes swimming in mayonnaise, sour cream and bacon bits would, by any other name, be unhealthy. Not when it's called "salad". If it's got a few baby spinach leaves scattered through, it pretty much cancels out the croutons, egg, parmesan, avocado and blue cheese sauce. Gone. Stop quibbling over semantics. It's "salad".

It's not just what goes in the salad though. Even when it's truly healthy and all freshly plucked organic rocket and micro-herbs drizzled with lemon, it's still trying to make you obese. This week, The New York Times stuck the crucifix into the heart of the lettuce with a 1300-word feature on How Salad Can Make Us Fat. "Ordering a side salad to go with your bacon cheeseburger is a deliberate and arguably rational trade-off between pleasure and health," the article explains, "but consumer researchers have found that the mere presence of a healthy option on a menu increases the chances that you'll order the least healthy choice. "You're more likely to choose French fries if there's a green salad available – a realisation that fast food restaurants have profited from handsomely." Not just fast food restaurants. In one study, researchers hooked up trackers to 1000 supermarket trolleys. They found that shoppers who popped some greens in their trolley were more likely to beeline straight to the ice cream or beer section.

Fascinating creatures we are. Another study found that if you try to guess the calories of a burger that has three celery sticks beside it, you guess about 420 kilojoules less (about the equivalent of a thickly cut slice of bread), than if the burger is by itself. It's enough to make you want to add bacon and sausages to your baby spinach and just be done with it. Especially when you consider that everything is bad for you anyway and those of us with strong self-control are actually most at risk because, in our confidence that we will make up for our indulgence later, we fall face first into the burger, hold the celery sticks. But, perhaps here lies our remedy. By thinking about "righting food wrongs" and compartmentalising food into "good" and "bad", we can find ourselves lost and trying to make shortcuts in the mentally sticky area in between.

If we are focused on our overall health and looking to nourish our bodies, there is room for a little indulgence – the odd salad with blue cheese dressing, might I suggest – and no need for excuses.