If you're buying lunch from a fast-food outlet, don't assume that everything that claims to be "healthy" is. Eight pieces of sushi, from St Pierres, which advertises with the line "it's time to eat healthy", has more calories than a mince pie from Jesters.
Subway markets itself as "the undisputed leader in fast healthy food" but a foot-long version of six of the chain's 12 "classic subs" would provide more than than half a person's daily calorie requirements in one hit, when sauce and cheese is added.
Nutritionist Catherine Sissons said it was always worth looking into what "healthy" meant. She said pre-packaged boxes with eight pieces of sushi were more than most women would need to eat and did not contain enough protein to be a balanced meal.
"If you choose sushi, go for the ones with protein laid on top of the rice or add in some sashimi or edamame beans on the side. Donburi, a mixture of teriyaki chicken and rice with salad, is a good combination. Be aware of the rice portion and find out how much is right for you."