CAN YOU TRUST THE NUMBERS ON THE PACKET?

If you want to know how many calories there are in a halloumi wrap purchased from a highstreet sandwich chain, you can find that information on the company’s website. A quick Google turns up one for 624.

The specificity of that figure is reassuring – a pinch more than 620 calories, not quite 630. But how accurate is this? After all, was the tapenade spooned in or measured on precision scales? And we suspect the halloumi was measured in slices rather than square centimetres. Are we right to be so sceptical? Well, research suggests that many food chains fall short when it comes to calorie reporting. In an analysis of 269 meals, published by the American Medical Association, one in five had at least 100 calories more than claimed on the menu, and lighter dishes, such as soups and salads, were the most likely to be under-reported. Mass-produced snacks, meanwhile, tend to be more homogeneous, with variations closer to 4%, according to a study in the journal Obesity.

Lesson learned

By eating out at cafe chains, you’re essentially entrusting your macros to a busy kitchen staffer. Consider labels a rough estimate, and learn to judge portions by eye: one or two fist-sized heaps of carbs, a palm-sized portion of protein and a large handful of veg are what you should be aiming for.