Gone are the days when food shopping involved a visit to the butcher, baker, greengrocer and delicatessen. Now we expect the supermarket to offer everything we need to restock the fridge for the week. It's a one-stop shop, but variety is still the key to a healthy and nutritious diet.

There are healthy options on every aisle of course, but we often stick to what we know. However, by simply swapping one type of pasta for another, or choosing fruit that hasn't been flown halfway around the world, you can dramatically improve the nutritional quality of your diet. Next time you're doing the weekly shop, try to make one healthy change in each aisle of the supermarket to improve your health as well as your running.

Cereal thriller
Breakfast cereals are obviously ideal first thing in the morning but they're also great after a long run or to snack on throughout the day. Unrefined whole-grain cereals are packed full of fibre and slow-release energy to keep you going for longer. They also provide B-vitamins, which convert carbohydrate to energy and are low in fat. As a general rule, the shorter the ingredients list, the higher the nutritional value. Avoid sugary and refined cereals such as cornflakes, rice cereals, puffed cereals (wheat, corn or rice) and anything honey-covered for breakfast. Research suggests that eating foods like these, which have a high glycaemic index (GI), first thing in the morning causes a rapid blood sugar high. Because of this imbalance, we are much more likely to overconsume in the form of high-calorie snacks later in the day.
Swap Shop The best breakfast cereal choices for runners are whole porridge oats, Weetabix, Shredded Wheat and sugar-free muesli.

Daily bread
The bakery provides a wealth of healthy options. Whole-grain bread is a great source of fibre and is rich in B-vitamins, essential for runners to convert carbohydrate into glucose. While refined varieties such as white bread are not “bad” foods, they do have a high GI and much of their natural goodness is removed in the milling process.
Swap Shop Always read the ingredients list and look for the words “whole-grain wheat flour” listed as the first or second ingredient.

Go nuts
You don't need to steer clear of the supermarket snack aisle altogether but you should avoid some of the products on offer. Swap crisps, biscuits and other junk foods for nutrient-packed dried fruit, nuts and seeds. Unsalted nuts and seeds are a great source of protein and high in essential amino acids, the building blocks of protein in your body, as well as essential fats and many vitamins and minerals. Nut butters are also healthy option for runners: again the fewer the ingredients, the healthier they're likely to be.
Swap Shop Check the label and avoid peanut and other nut butters that contain hydrogenated vegetable oils and corn syrup.

Flesh, fish and fowl
Lean meat is an excellent source of the protein and iron essential for transporting oxygen to working muscles. Poultry, especially the white meat, is lower in fat than red meat. The omega-3 essential fatty acids in fresh oily fish will improve running performance by enhancing oxygen delivery and energy levels, as well as having an anti-inflammatory effect on any strains or niggles you pick up.
Swap Shop Instead of opting for pieces of larger fish, such as salmon and tuna, go for whole smaller varieties such as mackerel and sardines, which are currently in season: they'll be fresher and contain more nutrients. Look for firm flesh with iridescent skin and clear, bright eyes. With increasing concerns over dwindling fish stocks, look out for fish with the MSC (Marine Stewardship Council) blue fish tick from sustainable fisheries.

Can it
Tinned oily fish, such as salmon, tuna and sardines, are a convenient source of the protein your body needs to maintain and repair muscles after a long run. Choose tuna canned in spring water or brine and sardines in tomato sauce rather than oil. Tinned pulses are another low-fat protein source, and they also provide carbohydrate to fuel your muscles during a run.
Swap Shop Swap pulses tinned “in salt and sugar” with those “in water”. Choose baked beans with less added sugar and salt.

Carbo load
Pasta and rice are a distance runner's friends, but the type you choose could have a big impact on your running performance. By choosing wholewheat varieties instead of refined pasta you'll enjoy more fibre and additional B-vitamins that are crucial to energy metabolism. Swap quick-cook white rice for basmati or wild rice: the latter have a lower GI providing a slower release of energy to sustain you on the run.
Swap Shop Exchange instant noodles, which are low in nutrients and often full of synthetic colourings and flavourings, with Chinese egg noodles.

Back to the sauce
Whether you choose Indian, Thai or Mediterranean, there is a huge variation in the nutrient content, salt and fat in pre-prepared cooking sauces. When you consume a lot of salt (the government's recommended daily amount is 6g), the body holds on to excess fluid, so you carry more weight. Swap your favourite tikka masala and other cream or coconut-based sauces for vitamin-packed tomato-based varieties.
Swap Shop Home-made sauces are lower in fat and salt and packed with nutrients. Use a can of chopped tomatoes, garlic and chopped fresh basil to make a simple pasta sauce. For Thai flavours, try grated ginger, garlic, finely chopped chillies and some lime juice.

Get fresh
Citrus fruits are loaded with vitamin C. This antioxidant has been shown to counteract free radical damage that results from exercise and reduce muscle soreness. Other great sources are potatoes, but think about swapping ordinary spuds for sweet potatoes. They'll boost your intake of vitamin A and are richer in vitamin C, iron, copper and calcium. Many fruit juices are also packed with vitamin C but don't be fooled into thinking that those in the chiller cabinet are necessarily nutritionally better. Choose fruit juices that are not made from concentrate and avoid any that are thickened with cornflour and those with “no added sugar” as they often contain artificial sweeteners.
Swap Shop Don't be tempted by strawberries in February. Instead choose seasonal fruits and vegetables that have travelled shorter distances to reach the supermarket: they'll be higher in vitamins and minerals.

Milk it
Dairy produce - milk, yoghurt and cheese - is one of the best sources of calcium for runners. This mineral is vital for the efficient functioning of muscles, including the heart. Swap whole milk for semi-skimmed or skimmed varieties and hard cheeses such as cheddar for Edam, Gouda and cottage cheese, which contain plenty of calcium and are lower in fat. As calcium is held in the non-fat part of milk, choosing lower fat options will not affect your intake. Low-fat yoghurts, however, may be no healthier than the full-fat options because the fat is often replaced with extra sugar and thickeners to improve the flavour and texture.
Swap Shop Fruit yoghurts are a great way to increase your daily fruit intake, but wise up to the language on their labels. A fruit “flavour” yoghurt means that the yoghurt is synthetically flavoured and may not have any fruit in while a fruit “flavoured” yoghurt will be flavoured with the real thing.

Spread betting
Every runner needs some fat in their diet, but think about swapping unhealthy saturated fats such as butter for healthier spreads containing polyunsaturated and monounsaturated fats. Avoid vegetable spreads that contain partially hydrogenated vegetable oil though, as these are likely to contain trans fats, thought to be bad for heart health.
Swap Shop Olive oil spreads are rich in healthy monounsaturated fats and vitamin E, a powerful antioxidant that promotes muscle recovery after an intense run and reduces free radical damage.