What is nutrient density?
In this post we will address the following:
- Do nutritious foods contain, by definition, essential (micro) nutrients?
- What factors affect nutrient density?
- What is nutrient bioavailability?
- Inactive vs active form of micronutrients
- Examples of nutrient dense foods and why they’re healthy
- What role does micronutrient dense food have in fat loss?
- Can processed food be nutrient dense?
- What are the consequences of nutrient poor diets?
- Which micronutrients are most important?
- Shopping list for nutrient dense food
- My favorite nutrient dense recipes
What is nutrient density?
You might think answering this question is simple: food that contains many nutrients is nutrient-dense, right? I mean, just look at the label. Add it all up.
In reality, there’s much more to it.
If I’m being honest, the big problem is that food labels lie. You don’t get the nutrients you think you’re getting. What you’ve been told about what is nutritious and what isn’t is mostly nonsense. That being said, how can we make sense of nutrient density?
We start far back with the Paleo concept. Our ancestors evolved to eat diets that were nutritionally complete, meaning they contained all of the essential micronutrients they needed to function. These included vitamins, minerals, amino and fatty acids. Then there were the macronutrients, protein, fat and carbs. Only dietary fat and protein turned out to be essential, not carbs.
Our ancestors didn’t always succeed in getting enough food or the right kind. When they didn’t, this could lead to nutrient deficiencies which cause disease and eventually be lethal. Thanks to modern science we have a good idea of what’s is essential and what isn’t. However, although we’re pretty confident in what’s essential and what isn’t, how much of each essential micronutrient we should have to be healthy is much less clear. In other words, beware of official RDAs, some are total guesses others are rigorously established.
There are 16 essential minerals, 13 essential vitamins, 2 essential fatty acids and 20 amino acids; 9 are essential amino, 6 are conditionally-essential amino acids (since we don’t always make enough ourselves) and are 5 non-essential amino acids (since we always make enough ourselves).
Nutrient dense foods will have both (a) abundant quantities of these micronutrients and (b) a wide range of them.
The punch line of nutrient density?
There is no one-food which has the perfect amounts of everything you need. However, the foods that get you super close! They are animal sourced foods. Which ones? Eggs, rib-eyes or salmon. These are phenomenally nutrient dense food with sufficient calories to contribute to a nourishing and filling meal for hours and hours. And they’re both keto and Paleo!
When considered individually and relative to animal sourced foods, vegetables, fruit and nuts are not particularly nutrient dense. Indeed, they lack a complete range of micronutrients, especially amino acids, some vitamins and minerals as well the fatty acid DHA. Nevertheless, it is also true that they contain a fair bit of micronutrients which can be a good addition to one’s diet.
Nutritious foods contain, by definition, essential (micro)nutrients
We all need a certain amount of energy and micronutrients for our body to function. Without listing all the nutrients, lets cover some important facts about nutrient density. Not all kinds of nutrients and combinations will do.
Everyone will eventually become sick without vitamin B12, one of the essential B vitamins. The various micronutrients arose out of millions of years of evolution, where it was better for humans to get their vitamin B12 from the environment (food) rather than make it themselves (internal cellular production).
We all need a certain amount of dietary protein and fat to function. Those are the essential macronutrients. It seems our brain needed glucose so much that it was better for it if we produced it ‘on-demand’ rather than through the diet. Indeed, there is no such thing as an essential dietary carbohydrate. Furthermore, humans evolved as apex predators hunting large fatty game, and even scavenging the fatty marrow by breaking open the bones of left-over kills from other animals. It’s no surprise this is part of why we evolved to be exceptional fat and ketone burners.
You have to eat enough protein to get those essential amino acids which help maintain your basic physiology. At least 0.8 g/kg of body weight per day is recommended to avoid dying slowly from muscle wasting . But to be healthy? You should eat quite a bit more. Try 1.5 g/kg of body weight per day from high quality animal protein as a good starting point.
The fat called DHA (docosahexaenoic acid) is only found in animal sourced foods and is an essential fat. You can easily obtain enough from fish, eggs and ruminants. Most importantly, do not eat seed oils as they’ll overwhelm DHA’s activity, so to speak. The only other essential fat is AA (arachidonic acid). You don’t have to make any effort to get it in your diet because it’s everywhere – in plant and animal foods. To guard against having too much AA just avoid seed oils (again). Other kinds of fats are not essential but they are good energy sources, for example the monounsaturated fat from bacon and olives or the saturated fat from beef and avocados.
What factors affect nutrient density?
It would go beyond the scope of this article to cover all essential micronutrients, so we will focus on the ones that people tend not to get enough of.
A food item is nutrient-dense if it can provide sufficient essential nutrients when eaten in reasonable amounts. For instance, vegetables contain the inactive form of vitamin A (beta-carotene). So you would have to eat ridiculously large volumes of carrots to cover your vitamin A demand for example. Consequently, carrots are not considered a dense source of vitamin A. It would displace too many other more nutrient complete foods.
Animal foods contain the active form of vitamin A (retinol). For example, 100 g of beef liver contains enough retinol, the active form of vitamin A, to sustain a person’s retinol needs over a few weeks ! This is a prime example of a food being extremely dense in the active form of vitamin A.
Active versus inactive? Few people want to navigate that. Nutrita developed a food search engine to guide you throw this maze. Nutrita’s unique food scoring system includes a nutrient density score and a Keto score to easily put together nutrient dense ketogenic recipes.
There is, of course, no single food or recipe that contains ALL essential nutrients in perfect amounts (although a rib-eye isn’t far off…). Some foods are particularly rich in certain nutrients and there’s a simple rule of thumb to make sure you get a lot of those in; make high-quality animal protein the centerpiece of your meal. That being said, there is more to it than that.
Bioavailability is a really important concept. We’ve been talking about it but lets spell it out. It’s basically a percentage score for how much of a nutrient you can absorb and use. Is it 80%? 50% Let’s explore several of the factors that determine bioavailability.
Active versus inactive form
Most vitamins and some fatty acids come in different forms. There is an active form, which is the one that the body needs. Some inactive forms can be converted into the active form, but it always comes with considerable costs. One example: β-carotene has a conversion rate of 3.6 to 28. This means that getting retinol from a carrot is 360% to 2,800% less efficient than it is from beef liver. For this reason, it makes much more sense to cover the demand for this vitamin by eating the active form from animal-sourced foods.
The term distribution refers to how much each amino acid, of which there are 20, is present in a food. Amino acids are the building block of protein. There are nine essential amino acids, and your body needs a specific amount of each. What does that mean when choosing your source of protein? That means that all protein sources aren’t equal and that it is crucial to choose high-quality protein; high bioavailability of amino acids and their proper distribution. As a rule of thumb, animal protein has a much higher bioavailability than plant protein. Eggs are the gold-standard as we can absorb nearly all of an egg, 98% to be exact! Salmon in contrast is about 81% bioavailable.
On a true, unsupplemented vegan diet you would not meet your basic amino acid requirements, however much you eat. The primary worry is methionine and glycine deficiencies. In adults these deficiencies are eventually life-threatening, but in infants, a vegan diet can be lethal within a year . It’s important for all people, but especially vegetarians and vegans, to eat considerably more (high quality) protein than the average person presently does.
Anti-nutrients are very common in plant-based foods. They stick to minerals like iron and zinc and thus make it harder for our digestive system to absorb it all . For this reason, mineral values on many food labels (e.g. a pasta box) are over inflated. You would have to eat ridiculous amounts of that food to reach the stated values.
Which foods are nutrient-dense?
The two prime examples of extremely nutrient-dense food are liver and eggs.
Let’s start with eggs. As mentioned already, their protein is of the highest quality you can find. An egg has an ideal amino acid composition, and your body can use 98% of it to build proteins. Eggs also contain essential omega-3 fatty acids. Moreover, they provide pretty much all vitamins and minerals in decent amounts .
The only thing that eggs are low in, is vitamin C. Vitamin C is, however, abundant in most other foods, especially plants, so most people get more than enough of this vitamin. Interestingly, if you follow a low-carb or carnivorous diet, your vitamin C need decreases a lot. One reason is because the less sugar you eat, the more easily you can take up vitamin C from your gut as there’s less sugar present to compete with it . The other reason is that when you eat very little sugar your body is free to upregulate some of its own antioxidants and so relies less on dietary sources like vitamin C. However, you can still easily obtain lots of vitamin C from plants on a keto diet staying under 2% of carbs, for instance from a little low-sugar fruit or some plain old lemon juice.
Now to liver. First of all, liver is the number one source for retinol, the active form of vitamin A. Eat a piece of liver every few weeks, and you can dump any pseudo-vitamin A sources. It is also rich in pretty much all B vitamins, potassium, choline, and even vitamin C (when fresh and cooked lightly)! On a ketogenic diet, regular consumption of liver covers any worries you may have about keeping the benefit from a diet rich in in vitamin C. If you want or need to, you can count on animal sourced foods to avoid scurvy (a vitamin C deficiency)!
Besides these two there are of course many more nutrient-dense foods:
Avocados are a great source of potassium [9,10]. They are also ideal for a ketogenic diet since they are very high in fat and low in carbs. Vegetables are in general less nutrient-dense than animal-sourced food, because of the three reasons mentioned above: amino acid distribution, anti-nutrients and inactive forms. They also contain the inactive form (e.g. ALA) of certain essential micronutrients, like DHA. ALA is found in plants like flax seeds and DHA in animals like sardines.
This doesn’t mean “don’t eat vegetables”. They do contain plenty of micronutrients and energy that can be healthy and taste good. However, they should never form the base of someone’s food pyramid since, alone, they cannot meet the basic needs of human biology like animal sourced foods do. So be pragmatic, and make it a priority to eat enough animal-based foods for nourishment. Then certain vegetables, fruit and starches can find their place in your diet if you react to them well (most people do).
As you can see, a well-formulated paleo or ketogenic diet that is based on animal sourced foods is automatically very nutrient-dense.
How nutrient-dense food helps with fat loss
We all need to cover our nutrient demands. We need a certain amount of energy to survive, but we also need essential micronutrients to function.
One idea to explain why people are fat says that they eat nutrient-poor food that is also calorie-dense, thus keeping them hungry so that they can keep eating until micronutrient needs are met . Another idea is that of “protein leverage”. Same thing as above but with protein; you’ll never feel full if you don’t get enough protein .
In different words, junk-food seems to be the opposite of nutrient dense, so nutrient poor. Indeed, it’s simultaneously high in energy (fat or carbs), low in protein and low in micronutrients. It’s got other problems too, like trans-fats, sugars, refined starches and oxidized oils: the perfect recipe to make you sick and fat. No, thanks!
Junk-food usually scores very high on the insulin index of foods (how much insulin your food causes you to release). Junk-food is nearly always low in nutrient density. This combination is the total opposite of foods like meat and low-starch vegetables. Together, the meat and vegetables can form a nutrient dense meal that doesn’t stimulate insulin excessively. Many people overcome fat-loss stalls on a keto diet by ditching so-called keto treats for more meat and vegetables.
So, is there any processed food that is nutrient-dense? There certainly is, in a ‘technical loophole’ sense. In today’s world, you can fortify anything with essential nutrients to make up for nutrient loss from food processing. Bread, for instance, is usually fortified with vitamin B12, iron and iodine to prevent nutrient deficiencies (in vegans, for example). This form, also found in supplements, is the inactive form (hydroxocobalamin) of vitamin B12. The active form is called methylcobalamin.
The problem is you can’t just add micronutrients to foods to make them nutrient-dense; that’s unscientific, but that’s what most food manufacturers do. Just like you can’t pop mutis to make up for a nutrient poor diet. Another reason to avoid fortified foods is that they certainly contain oxidized seed oils and mostly consist of refined carbs. Consuming seed oils like sunflower oil and soybean oil increases one’s risk for obesity, diabetes, cardiovascular disease, and cancer . Quality olive oil doesn’t make that list, fortunately. Do yourself a big favor and get your nutrients from better sources than seed oils.
Which micronutrients are the most important?
The list below is by no means complete as it would go beyond the scope of this article. However, these are the ones that most people tend to get short of, so make sure to get enough of those:
It’s essential to eat enough high-quality protein, at least 1.5 g per Kg body weight. If you tried to do that with low-quality plant-based proteins you would have to eat such large quantities of food that it wouldn’t be physically possible. This is why targeted supplementation of essential amino acids is crucial in vegans and vegetarians. If you’re keto but on the plant-based spectrum then get your essential amino acids from eggs, dairy and bivalve crustaceans (a category of shellfish).
Most B vitamins are essential for nerve function. Unfortunately, nerve damage is hard to reverse, so you want to avoid a lack of B vitamins. Most vitamin B deficiencies are rare. But one that does occur surprisingly frequently and more and more so as the plant-based movement grows, is vitamin B12 deficiency . All animal foods contain sufficient amounts of vitamin B12, but you should still check your levels as inflammatory conditions and gut dysbiosis can lower your ability to absorb vitamin B12.
Most people don’t get enough magnesium . This mineral is especially crucial when you are starting a low-carb diet (such as keto or paleo) because you lose a lot of water initially and along with it important minerals. Dark chocolate, avocados, almonds, macadamia nuts, and spinach are particularly rich in magnesium.
Choline is needed to make specific phospholipids that are part of the plasma membrane. Plasma membranes surround every single cell in the body. Sufficient amounts of choline protect against metabolic syndrome . Liver and eggs are both rich in choline.
Vitamin D also called the sunshine vitamin, is hard to get during winter months, especially when you are dark skinned. Fatty fish is the best source for vitamin D from food. Vitamin D also helps you to absorb certain other nutrients, such as calcium and phosphorus .
Vitamin A (retinol)
Retinol has various functions in the body: your nerve cells, blood cells, skin, eyes, immune system, and bones all need this vitamin to function properly. An acute deficiency is rare, but it can be hard to get optimal amounts from plant-based foods. Liver is by far the best source for retinol and also rich in so many other nutrients!
Most vegetables and mushrooms are excellent sources for potassium, and liver, again, is also a decent source, along with fish like halibut. The only problem is that it gets easily lost when you boil the vegetables in water. So make sure to either use the water for something else or find an alternative method to cook your vegetables. Frying them in a pan with butter is always a good idea.
Omega-3 fatty acids
The omega-3 fat DHA is essential, and you only find it in fish, eggs, and meat. The plant-derived omega-3 fatty acid alpha-linolenic acid (ALA) has an abysmal conversion rate, so you won’t be able to get enough essential omega-3 fatty acids from chia seeds, flax seeds or even walnuts .
Shopping list for nutrient dense food
Nutrita makes it easy to see which foods are nutrient-dense and also respect the other healthy eating principles. This list is just supposed to give you a basic idea of nutrient dense foods you might enjoy. A few of them might seem unappetizing, but you’d be surprised….
- chicken eggs
- quail eggs
- liver and other organ meats:
- brain (excellent source of omega-3 fats!)
- feet, ears, tail…
- all kinds of meat (grass-fed preferred):
- bone marrow (as a side with steak or to make bone broth)
- all kinds of fish and seafood
- codfish (also cod liver)
- all kinds of fresh or frozen vegetables (vegetables that grow above the ground are preferred)
- spinach, salad, kale, and other leafy greens
- all kinds of mushrooms
- fresh herbs
- pili nuts
- cashews (not too many)
- strawberries (botanically a nut)
My favorite nutrient-dense recipes
A nutrient-dense diet does not have to be complicated. Quite the the opposite. When you merely combine seafood, fish or meat with a side of veggies, it will be hard not to create a nutrient-dense meal!
Because animal foods are the densest sources of essential nutrients, I have the perfect recipes that showcase both!
How does Nutrita’s food search engine score the ingredients in this recipe?
- Ground beef (15% fat) has a Keto score of 9/10 and Nutrient density score of 6/10
- Onion (red) has a Keto score of 5/10 and Nutrient density score of 6/10
- Coconut cream has a Keto score of 9/10 and Nutrient density score of 1/10
- Coconut oil has a Keto score of 10/10 and Nutrient density score of 0/10
Average Keto score = 9/10 to 10/10
Average Nutrient density = 6/10
How does Nutrita’s food search engine score the ingredients in this recipe?
- Lobster has a Keto score of 7/10 and Nutrient density score of 10/10
- Bacon has a Keto score of 7/10 and Nutrient density score of 8/10
- Eggs has a Keto score of 9/10 and Nutrient density score of 8/10
- Onion (green) has a Keto score of 5/10 and Nutrient density score of 6/10
- Lemon juice has a Keto score of 6/10
- Garlic has a Keto score of 2/10 and Nutrient density score of 4/10
Average Keto score = 8
Average Nutrient density = 8/10 to 9/10
Any diet that primarily consists of animal sourced food is rich in essential nutrients. Plants are generally much less nutrient-dense relative to animal sourced foods, but they can still be healthy, nutritionally useful additions to one’s diet. So if your diet looks more like a steak with a salad and eggs than it does pizzas and smoothies, you’re doing it right.
Eat seafood, fish, eggs or meat every day. And if you want to, include vegetables as you like. Or fresh herbs, they add a lot of flavor to your dish. Nuts are also a good options but seeds less so, given they’re more difficult to digest and are not so nutrient rich. Fruit, especially low-sugar fruit makes for a great dessert. So go for berries rather than bananas.
As long as you’re avoiding foods that contain added sugar, flour and seed oils, and you’re not shying away from animal protein, your diet is probably pretty nutrient dense!
Raphael Sirtoli is the co-founder of Nutrita, a website helping people grasp cutting-edge nutrition science. Nutrita is also a mobile app that helps people follow well-formulated low-carb diets as well as reach their health and performance goals. Raphael has an MSc in Molecular Biology and is currently pursuing a PhD in Health Sciences at the University of Minho. His day job however is neuroscience research at the Behavioral n’ Molecular Lab where he studies the metabolic effects of antipsychotics in rodent models of schizophrenia. His understanding of metabolism, nutrition and clinical medicine forms the base upon which Nutrita derives its evolving knowledge. He loves open scientific debate, Crossfit, football, hiking, psychedelic medicine, cold water immersion and cooking for loved ones.