Healthy canned foods: which to choose and which to limit

Are canned foods healthy?

Yes, when the can contains little more than the food itself. It’s one of the questions we hear most often in consultations, and it usually comes with a little guilt. A simple canned food is the same food, cooked and packaged so it keeps.

Cooked pulses, tinned fish and vegetables in jars add variety and make it easier to eat well when time is short. The Spanish Agency for Food Safety and Nutrition recommends at least 3 servings of vegetables a day and 2 or 3 servings of fruit [3]. For pulses, at least 4 servings a week [3]. A simple canned food can help you meet those recommendations even on a difficult day.

What’s worth checking is what has been added to the food before packaging. A can containing water, the food and a little salt is easy to assess. A recipe with sauce, sugar and several ingredients is much less straightforward.

What should you check first on the label?

Start with the name of the food, then check the ingredient list, which is shown in descending order by weight [2]. For lentils, you would expect lentils, water, salt and sometimes an antioxidant. For crushed tomatoes, tomatoes and perhaps salt.

If you see sugar, syrups, sauces or ingredients you weren’t expecting, decide whether you want that prepared dish or just the basic food. In fruit, tomatoes and vegetables, the sugars row includes sugars naturally present in the food. To find out whether sugar has been added, look for words such as sugar, syrup or sugar syrup in the ingredient list.

Next, compare the salt per 100 g between two canned foods from the same group. The nutrition table gives values per 100 g, so you can compare two packages without relying on the serving size suggested by the brand [2].

The European Food Safety Authority sets an adequate sodium intake for adults at 2 g a day [1]. Labels show salt rather than sodium; salt is calculated by multiplying sodium by 2.5 [2]. The World Health Organization recommends that adults consume less than 5 g of salt a day.

The salt in a tin adds to the salt in bread, cheese, sauces and everything else you eat that day. If you have high blood pressure, this comparison goes hand in hand with our dietary guide for high blood pressure.

Before opening it, check the packaging too. Throw away a can that is swollen, rusty or dented around the seam without tasting its contents. Do the same if it sprays when opened or smells unusual.

How to drain and rinse canned food

For pulses and vegetables in brine, tip the contents into a colander and let the packing liquid drain away. If you want to reduce the salt in your meal, rinse them under running water and drain them again. Taste the dish before adding salt: often, you won’t need any.

For fish in oil, drain the oil if you’re going to dress the dish anyway. There’s no need to rinse the fish. For fruit, discard the syrup if you’re going to mix it with plain yoghurt or oats, so the sweetness doesn’t dominate the dish.

What’s different about pulses, fish, vegetables and fruit?

The table doesn’t rank these groups from best to worst. The same question applies to all of them: is this the food I was looking for, what has been added, and which part will I use?

Does the oil in canned food matter?

It does, because it becomes part of the dish. Fish in olive oil works well if you drain it or count that oil as the dressing for a salad, toast or stew. If the food is canned plain, add the oil you use at home afterwards.

The oil doesn’t tell you everything, either. A product with an oil you like may contain a lot of salt, while a plain one may need a side dish to make a meal. Read the whole label.

Which canned foods should you eat in moderation?

Save complete ready meals that only need heating, dishes containing cured meats, and sauces with ingredients you don’t recognise for occasional use. It’s harder to compare their salt, sugar and fat with a basic option.

Anchovies, olives and escabeche work better as a flavour accent. They add flavour to a generous serving of vegetables, potatoes or pulses without taking centre stage in the meal.

What mistakes do we often see in consultations?

Two comments come up often when we talk about pantry staples.

• “Canned foods are processed, so it’s better to avoid them.” With that idea, pulses disappear from the week because there’s never time to soak them. A can of chickpeas with water and salt contains the same pulse, already cooked.
• “If I drain them, they don’t contain salt any more.” Draining and rinsing remove the salt in the liquid, not the salt the food has absorbed. That’s why it’s still worth comparing labels.

How to put together a quick meal with canned foods

Think of a base, a protein and a vegetable. For example, rinsed chickpeas, plain tomatoes, drained mackerel and wholemeal bread. Or canned green beans, cooked potato, egg and a dressing you make yourself. Canned food saves time, and the meal is still your own.

For variety, alternate a meal with pulses, one with fish and one with canned vegetables. That way, you don’t rely on just one salty option or buy on impulse. If you’d like to read labels on other products, see our comparison of digestive biscuits.