Certain foods are so nutritionally dense that they have often been dubbed ‘superfoods’. While there are no specific criteria for a food to meet before it can be called a ‘superfood’, here are 15 foods that satisfy the general definition and are very much recommended by us.

Blueberries

Blueberries contain strong amounts of vitamins, phytochemicals, and soluble fiber. In a study published by the Circulation journal in 2013, blueberries were found to be of possible benefit to the heart. It was found that, in young women, flavonoids could lower the risk of particular heart conditions.

Kiwifruit

If you often struggle to sleep, try eating more kiwifruit. A small study that the Asia Pacific Journal of Clinical Nutrition published in 2011 hinted that kiwifruit consumption might promote better rest in sufferers of sleep disorders. We're assuming that New Zealanders sleep soundly, then...

Kale

Kale contains a huge number of nutrients considering its calorie count, which is only 50 for each 100g serving. Kale includes indole-3-carbinol and sulforophane, two bioactive compounds with demonstrated abilities to help tackle cancer. This superfood also has lots of potassium and calcium.

Strawberries

By consuming one cup of strawberries, you can meet the daily recommended intake of vitamin C, which is 90 milligrams for men and 74 milligrams for women. Strawberries could, studies suggest, help the building and repair of body tissues and help make eyes function more healthily.

Cauliflower

The glucosinolates in cauliflower are compounds capable of preventing carcinogens inflicting damage to the stomach and lungs. Through interacting with estrogen, cauliflower could assist in preventing such hormone-driven cancers as cervical, uterine, and breast cancers.

Oatmeal

Oatmeal is rich in lots of nutrients including fiber and antioxidants. It has been shown to be capable of helping digestion and the reduction of cholesterol levels, not to mention improving metabolism.

Pumpkin

Maybe, the next time you buy a pumpkin, you should eat it rather than carve a face in it for Halloween. This superfood does, after all, contain the provitamin beta-carotene. Your body can convert that into vitamin A, which can improve your immunity and make your eyes healthier.

Spinach

Perhaps strong bones, rather than big muscles, were why spinach always made Popeye such a force to be reckoned with. You only need to consume one cup of spinach to enjoy 12% of your RDA of calcium and sufficient vitamin K to help to prevent bone loss.

Eggs

Eggs are great for getting more protein into your diet, as each 70-calorie large egg includes 6g of protein. Also present in eggs are omega-3 fatty acids; these are crucial if you want to keep your heart healthy and your body functioning normally. Oh, and you shouldn’t forget the highly nutritious yolks either.

Garlic

This is today used to treat an array of conditions, among them high blood pressure, heart disease, and particular kinds of cancer. Meanwhile, garlic extract can, studies hint, be used to treat women's yeast infections, as well as prostate problems in men.

Coconut oil

Coconut oil is a great choice of cooking oil. Most of coconut oil's fatty acids are medium chain triglycerides (MCTs) - which, more so than other fats, can boost satiety and metabolism. This makes coconut oil very suitable if you are looking to lose weight.

Almonds

There's 3.4g - roughly 14% of the recommended daily intake - of fiber in each one-ounce, 191-calorie serving of almonds. These nuts also have strong amounts of vitamin E, iron, magnesium, potassium, and calcium; the last of those is good for ensuring strong bones and teeth.

Apples

Yes, an apple a day can indeed keep the doctor away. You would be less likely to need that doctor to help diagnose cardiovascular disease, asthma, or diabetes in yourself, as increased intake of apples has been associated with lowered risk of all of these conditions, plus certain cancers.

Seaweed

Many modern diets lack iodine, which is vital for thyroid health and, due to this, the body's overall health. An iodine deficiency can result in fatigue, hypothyroidism, and mental retardation. However, there's a lot of iodine in seaweed, which you could benefit from eating once or twice weekly.

Dark chocolate

Your eyes do not deceive you - we have actually listed dark chocolate as a superfood. Eat it as long as its cocoa content is at least 70%; that content will probably be advertised on the front of the wrapping. Dark chocolate has antioxidants capable of reducing blood pressure and increasing blood flow. You could eat two squares of it after dinner rather than tuck into pudding, for instance.

The list of superfoods worth considering doesn't stop with these foods; we have not mentioned, for example, Greek yogurt, quinoa, broccoli, and beets. The huge choice of superfoods can make it easy for you to find some that you will love tasting, regardless of what your other pressing nutritional requirements may be.