As many countries urge populations to stay at home, many of us are paying more attention to our diets and how the food we eat can support our health. To help sort out the fact from the fiction, BBC Future is updating some of our most popular nutrition stories from our archive.

Our colleagues at BBC Good Food are focusing on practical solutions for ingredient swaps, nutritious storecupboard recipes and all aspects of cooking and eating during lockdown.

Imagine the ideal food. One that contains all the nutrients necessary to meet, but not exceed, our daily nutrient demands. If such a food existed, consuming it, without eating any other, would provide the optimal nutritional balance for our body.

Such a food does not exist. But we can do the next best thing.

The key is to eat a balance of highly nutritional foods, that when consumed together, do not contain too much of any one nutrient, to avoid exceeding daily recommended amounts. That's especially important when we are thrown out of our usual routines, as so many have been with enforced isolation during the current pandemic.

Scientists studied more than 1,000 foods, assigning each a nutritional score. The higher the score, the more likely each food would meet, but not exceed your daily nutritional needs, when eaten in combination with others.

Calculated and ranked by scientists, these are the 100 most nutritious foods:

Please note: a few of the foods listed are endangered species, which we would not recommend. We would advise researching the provenance of all ingredients if buying them yourself.

A bright orange tuber, sweet potatoes are only distantly related to potatoes. They are rich in beta-carotene.

Figs have been cultivated since ancient times. Eaten fresh or dried, they are rich in the mineral manganese.

Ginger contains high levels of antioxidants. In medicine, it is used as a digestive stimulant and to treat colds.

Pumpkins are rich in yellow and orange pigments. Especially xanthophyll esters and beta-carotene.

Used in folk medicine and as a vegetable, studies suggest burdock can aid fat loss and limit inflammation.

A type of cabbage. Brussels sprouts originated in Brussels in the 1500s. They are rich in calcium and vitamin C.

Broccoli heads consist of immature flower buds and stems. US consumption has risen five-fold in 50 years.

Unlike broccoli, cauliflower heads are degenerate shoot tips that are frequently white, lacking green chlorophyll.

The water chestnut is not a nut at all, but an aquatic vegetable that grows in mud underwater within marshes.

One of the foods richest in glutathione, an antioxidant that protects cells from toxins including free radicals.

Cantaloupe melon - rich in antioxidants

Dried plums are very rich in health-promoting nutrients such as antioxidants and anthocyanins.

Though nutritious, recent evidence suggests octopus can carry harmful shellfish toxins and allergens.

Carrots first appeared in Afghanistan 1,100 years ago. Orange carrots were grown in Europe in the 1500s.

Unlike summer squashes, winter squashes are eaten in the mature fruit stage. The hard rind is usually not eaten.

The same species as other peppers. Carotenoid levels are 35 times higher in red jalapenos that have ripened.

Rhubarb is rich in minerals, vitamins, fibre and natural phytochemicals that have a role in maintaining health.

Their red and purple colour is produced by anthocyanins that have antioxidant and anti-inflammatory properties.

Red currants are also rich in anthocyanins. White currants are the same species as red, whereas black currants differ.

Most citrus fruits grown worldwide are oranges. In many varieties, acidity declines with fruit ripeness.

A high proportion of carp is protein, around 18%. Just under 6% is fat, and the fish contains zero sugar.

Did you know? (Credit: Fact and Story)

A variety of the species Cucurbita maxim. Tear-drop shaped, they are often cooked in lieu of pumpkins.

An unusual citrus fruit, kumquats lack a pith inside and their tender rind is not separate like an orange peel.

Often called jacks, Florida pompanos are frequently-caught western Atlantic fish usually weighing under 2kg.

These fish are rich in long-chain fatty acids, such as omega-3s, that improve blood cholesterol levels.

Sour cherries (Prunus cerasus) are a different species to sweet cherries (P. avium). Usually processed or frozen.

Closely related to salmon, rainbow trout are medium-sized Pacific fish also rich in omega-3s.

Pregnant and lactating women are advised not to eat perch. Though nutritious, it may contain traces of mercury.

Green beans, known as string, snap or French beans, are rich in saponins, thought to reduce cholesterol levels.

Evidence suggests lettuce was cultivated before 4500 BC. It contains almost no fat or sugar and is high in calcium.

Leeks are closely related to onions, shallots, chives and garlic. Their wild ancestor grows around the Mediterranean basin.

Rolled out leeks can make a healthier lasagne than using pasta sheets

Powdered cayenne pepper is produced from a unique cultivar of the pepper species Capsicum annuum.

Kiwifruit are native to China. Missionaries took them to New Zealand in the early 1900s, where they were domesticated.

Kiwifruits are edible berries rich in potassium and magnesium. Some golden kiwifruits have a red centre.

Grapefruits (Citrus paradisi) originated in the West Indies as a hybrid of the larger pomelo fruit.

An oily fish, one serving can provide over 10 times more beneficial fatty acids than a serving of a lean fish such as cod.

Another oily fish, rich in cholesterol-lowering fatty acids. Canned salmon with bones is a source of calcium.

A salad leaf, known as rocket. High levels of glucosinolates protect against cancer and cardiovascular disease.

Though low in energy, chives are high in vitamins A and K. The green leaves contain a range of beneficial antioxidants.

Also extracted from the pepper species Capsicum annuum. A spice rich in ascorbic acid, an antioxidant.

A low-energy, nutrient-dense food that are an excellent source of folate, potassium and vitamins A, C and E.

Did you know? (Credit: Fact and Story)

Fruit that has not yet ripened or turned red. Consumption of tomatoes is associated with a decreased cancer risk.

The cultivated lettuce (Lactuca sativa) is related to wild lettuce (L. serriola), a common weed in the US.

Young taro leaves are relatively high in protein, containing more than the commonly eaten taro root.

Also known as butter beans, lima beans are high in carbohydrate, protein and manganese, while low in fat.

A good source of riboflavin (vitamin B2), though the skin mucus of eels can contain harmful marine toxins.

A large fish, rich in omega-3s. Pregnant women are advised to limit their intake, due to mercury contamination.

A Pacific species also known as silver salmon. Relatively high levels of fat, as well as long-chain fatty acids.

Harvested when immature, while the rind is still tender and edible. Its name refers to its short storage life.

Also known as haricot or pea beans. The fibre in navy beans has been correlated with the reduction of colon cancer.

Banana fruits with a variety of antioxidant, antimicrobial, hypoglycaemic and anti-diabetic properties.

Plantain, a variety of banana fruit

Peas are an excellent source of protein, carbohydrates, dietary fibre, minerals and water-soluble vitamins.

Also called black-eyed peas. As with many legumes, high in carbohydrate, containing more protein than cereals.

Also known as butterhead lettuce, and including Boston and bib varieties. Few calories. Popular in Europe.

A raw, unprocessed and unfrozen variety of sour cherries (Prunus cerasus). Native to Europe and Asia.

Walnuts contain sizeable proportions of a-linolenic acid, the healthy omega-3 fatty acid made by plants.

Contains more minerals and vitamins (especially vitamin A, calcium, phosphorus and iron) than many salad crops. Spinach appears twice in the list (45 and 24) because the way it is prepared affects its nutritional value. Fresh spinach can lose nutritional value if stored at room temperature, and ranks lower than eating spinach that has been frozen, for instance.

A relative of celery, parsley was popular in Greek and Roman times. High levels of a range of beneficial minerals. 

An Atlantic fish, among the top five most caught of all species. Rich in omega-3s, long-chain fatty acids.

A generic name for a number of related medium-sized oily fish species. Popular in the Mediterranean area.

Variants of the cabbage species Brassica rapa, often called pak-choi or Chinese mustard. Low calorie. 

Did you know? (Credit: Fact and Story)

The brassica Lepidium sativum, not to be confused with watercress Nasturtium officinale. High in iron.

A ’stone’ fruit relatively high in sugar, phytoestrogens and antioxidants, including the carotenoid beta-carotene.

Fish eggs (roe) contain high levels of vitamin B-12 and omega-3 fatty acids. Caviar often refers to sturgeon roe.

Species of oily freshwater fish related to salmon. Common in the northern hemisphere. Rich in omega-3s.

A herb rich in carotenoids, used to treat ills including digestive complaints, coughs, chest pains and fever.

Also known as cos lettuce, another variety of Lactuca sativa. The fresher the leaves, the more nutritious they are.

One of the oldest recorded spices. Contains sinigrin, a chemical thought to protect against inflammation.

A large white, low fat, protein-rich fish. Cod livers are a source of fish oil rich in fatty acids and vitamin D.

Various species, but often referring to the North Atlantic fish Merlangius merlangus that is related to cod.

A leafy salad plant, rich in the minerals phosphorous, iron and calcium, and vitamins such as A and C.

Kale - an excellent side dish

Not to be confused with broccoli. It has thinner stems and smaller flowers, and is related to turnips.

The pungent fruits of the Capsicum plant. Rich in capsaicinoid, carotenoid and ascorbic acid antioxidants.

Lean, protein-rich shellfish. Often eaten lightly cooked, though care must be taken to avoid food poisoning.

Another salad leaf belonging to the Brassica genus of plants. A headless cabbage closely related to kale.

A spicy, sweet herb traditionally used to protect the heart. Thought to be an antifungal and antibacterial.

A source of phytochemicals such as vitamin C, E and A, as well as phenolic compounds and carotenoids.

A salad crop especially high in magnesium, folate, vitamin A and the carotenoids beta carotene and zeazanthin. Freezing spinach helps prevent the nutrients within from degrading, which is why frozen spinach ranks higher than fresh spinach (no 45).

The word dandelion means lion’s tooth. The leaves are an excellent source of vitamin A, vitamin C and calcium.

The red flesh of pink varieties is due to the accumulation of carotenoid and lycopene pigments.

A shellfish low in fat, high in protein, fatty acids, potassium and sodium.

Did you know? (Credit: Fact and Story)

Closely related to Atlantic cod. Its livers are a significant source of fish oil rich in fatty acids and vitamin D.

Rich in vitamins. Its wild cabbage ancestor was a seaside plant of European or Mediterranean origin.

Known as spring onions. High in copper, phosphorous and magnesium. One of the richest sources of vitamin K.

Also called walleye pollock, the species Gadus chalcogrammus is usually caught in the Bering Sea and Gulf of Alaska. A low fat content of less than 1%.

A fast freshwater predatory fish. Nutritious but pregnant women must avoid, due to mercury contamination.

Individual green peas contain high levels of phosphorous, magnesium, iron, zinc, copper and dietary fibre.

An oblate orange citrus fruit. High in sugar and the carotenoid cryptoxanthin, a precursor to vitamin A.

Unique among vegetables, it grows in flowing water as a wild plant. Traditionally eaten to treat mineral deficiency.

Celery that is dried and flaked to use as a condiment. An important source of vitamins, minerals and amino acids.

Parsley that is dried and ground to use as a spice. High in boron, fluoride and calcium for healthy bones and teeth.

Sprinkling the occasional parsley on your meal could be a good idea

A family of mainly marine fish, with red snapper the best known. Nutritious but can carry dangerous toxins.

The leaves of beetroot vegetables. High in calcium, iron, vitamin K and B group vitamins (especially riboflavin).

A good source of B vitamins and minerals. Pork fat is more unsaturated and healthier than lamb or beef fat.

A very rare dietary source of betalains, phytochemicals thought to have antioxidant and other health properties.

Including the seeds of other squashes. One of the richest plant-based sources of iron and manganese.

Tiny black seeds that contain high amounts of dietary fibre, protein, a-linolenic acid, phenolic acid and vitamins.

Sole and flounder species. Generally free from mercury and a good source of the essential nutrient vitamin B1.

The Atlantic species. A deep-water fish sometimes called rockfish. High in protein, low in saturated fats.

Cherimoya fruit is fleshy and sweet with a white pulp. Rich in sugar and vitamins A, C, B1, B2 and potassium.

Rich in mono-unsaturated fatty acids. Promote cardiovascular health and may help with diabetes.

Did you know? (Credit: Fact and Story)

This page was originally published as an infographic but has been updated to fix a technical problem.  

Food selection, ranking and cost based on the scientific study “Uncovering the Nutritional Landscape of Food”, published in the journal PLoS ONE. (Download the dataset).  

Nutritional data based on The United States Department of Agriculture, Agricultural Research Service’s National Nutrient Database for Standard Reference, Release 28.

Nutritional insights from The Encyclopaedia of Food and Health (2016), published by Elsevier Science.

Produced for BBC Future by Fact & Story.