So we are told by some ready-made sandwiches are dangerously high in fat. Joanna Moorhead offers a guide to a healthy office lunch
What's the perfect office lunch? According to nutritionists, it's not what many of us opt for - the prepacked supermarket sandwich, which comes oozing with mayo and could contain as much as two-thirds of the maximum amount of fat recommended for one day's intake. We've consulted nutritionists to find out what you should be doing to eat more healthily at your desk.
Make it yourself: If you've always feared the suppressed sniggers of fellow workers as you unpack your Tupperware, think again. Bringing a packed lunch in from home might not be glamorous, but it's almost certainly healthier than anything you can get at the shops (not to mention cheaper). "Ready-made sandwiches are usually made at least the day before you consume them," says Dr Susan Jebb, nutritionist at the UK Medical Research Council.
"The filling has to consist of something that will stay fresh and stop the bread getting soggy, and a layer of mayonnaise waterproofs it. Sandwich-makers don't use things like sliced tomatoes very often because that would get the bread wet - although of course it would make the meal lower in fat.
"Any sandwich you make at home will invariably be healthier, because you'll tend to cut thicker slices of bread, which keep your energy levels up for longer, and less filling. Another option is to go to a shop where the sandwiches are made in front of your eyes rather than a supermarket - in the shop you can ask for no butter or mayo or just a scraping of butter or mayo, and more lettuce and tomato."
Read the label: Reading the label may sound boring but, says Jebb, it's worth making the effort just once or twice because you'll quickly see which sandwiches to avoid and which to go for.
"The reason the cheese sandwiches did so badly in the survey is because cheese is really high in fat and there was nothing else in them to pack them out, like lettuce," she says.
"You want to look for lower levels of fat and salt and for fewer overall calories. Low-calorie options can be a good choice - some will give you a sandwich for around 300 or 350 calories compared with as many as 500 or 600 calories in some others." Bear in mind that less than 3g of fat per 100g makes food low fat, while anything over 20g of fat per 100g is considered high fat.
Think about the filling: "Some meats are quite fatty and will add a lot to the calorific and fat content," says Dr Anne Nugent of the British Nutrition Foundation. "Lean chicken, ham, low-fat sausage or lean roast beef are lower fat options. Lower-fat cheeses are also available." Jebb warns against assuming that something that sounds healthy really is.
"You might think roquefort and avocado sounds interesting and good for you," she says. "But actually it's a very high-fat choice. And think about what the sandwich maker will have added to the filling you're choosing - the egg mayo you make at home may have just a sprinkling of salt, but the shop-made version will be a lot saltier. Sandwiches packed with lettuce and tomato are going to be healthier than those made up just with fillings of cheese or egg."
What's on the side? If the sandwich is the main course item on your office lunch menu, the items round the edges make a big difference to the overall health rating of your meal. So think generally: drink water rather than something high-calorie, additive-packed and fizzy, and ditch the crisps and chocolate in favour of salad and fruit.
"Prepacked salads and fruit salad from the supermarket can be very expensive but it will be healthier," says Jebb. "Or why not buy a small packet of cherry tomatoes to munch on the side?" Nugent points out that if you have a fruit juice, some tomatoes and a piece of fruit with your meal, you'll be able to notch up three pluses on your quest for five portions of fruit and vegetables a day.
Dare to be different: We all know someone who's been eating the same chicken and mayonnaise sandwich day in, day out since they joined the company 20 years ago. But getting stuck in a rut with your lunch isn't just boring, it's also potentially unhealthy.
"If you're eating the same calorie-laden sandwich every day, that's going to have a big impact on your overall nutrition," says Jebb. "Ringing the changes on what you eat each day is healthier, especially if you look for alternatives that are good for you. It doesn't have to be a conventional sandwich - some wraps, and many pitta bread options can be good. And sushi, which is low in fat and contains the fish most of us aren't getting enough of, is a great choice."
What's more, seeking out alternatives to your usual lunchtime fare might have the added benefit of giving you a bit more exercise - and that, in turn, will help burn off the calories you're about to consume when you get back to your desk.