If you read ASweetLife often, you know that we believe a low-carbohydrate or ketogenic diet is key to managing both Type 1 and Type 2 diabetes. Keeping carbs low is the single best way to achieve tight, healthy, normal blood sugars, and is the best way to break the cycle of insulin resistance.
However, people with diabetes need their diets to do more than just optimize their metabolism. They also need to derive nourishment from their diet, just like everyone else. And the keto diet can accommodate many different foods and ways of eating, ranging from fully vegan to the 100% meat “carnivore” diet, and many points in between. Some low-carbohydrate foods are nutrient dense, and some are nutrient poor, and it pays to know the difference.
Raphael Sirtoli, co-founder of Nutrita Pro, an app that tracks key foods and nutrition, explains how to get the right nutrients, and why it’s important.
What is nutrient density?
The healthfulness of any one food goes far beyond a simple accounting of its calories or macronutrients. We can examine the wholesomeness of foods with much greater detail, chiefly by looking at vitamin and mineral content.
“Nutrient density” is the best way to approach this topic, and it’s a crucial concept in nutrition. The more nutrient dense a food is, the more nutrients (vitamins, minerals) you get for a standard amount of the food, measured in grams or calories.
As far as calculations go, it’s pretty simple. In fact, it’s too simple. There are many reasons why it’s inaccurate. Here are 3 important ones:
- With the ‘per calories’ approach we end up inflating the nutritional value of plants because they’re less energy dense than animal foods on average
- The calculation assumes perfect absorption of vitamins and minerals, ignoring important differences in how nutrients are taken up and (processed for energy or structural roles)
- It doesn’t account for the fact that some nutrients come in inactive forms that carry a cost for being converted into active ones.
Government and corporation food labels ignore these facts. The nutrient density score in the Nutrita Pro does not.
People are nourished not only by essential vitamins and minerals, but also by essential amino acids (protein) and fatty acids (fat).
So, with this new tool to figure out a food’s nourishing level, let’s take a look at which foods are most nutritious.
Most nutrient dense low-carb foods
1. Organ meats (offal)
Organ meats are probably the most nutrient-dense foods available, outranking fruits, vegetables and muscle meats in pure nutrient-density. They are particularly rich in B vitamins and in important minerals, such as iron and magnesium, that can be otherwise rare in common foods. Liver, for example, is packed with vitamins A (retinol) and riboflavin, copper, niacin and Vitamin B6. Some cuts, such as beef tripe and chicken feet, are particularly rich in gelatin (collagen).
Organ meats are often considered an acquired taste at best in today’s United States, but they are cherished ingredients in much of the world, from France to Mexico to China. With the right touch they could become a delicious part of your diet too.
2. Fish, shellfish, meat, eggs and dairy
Non-organ animal products are probably the second most nutritionally-dense group.
Beef is a truly complete source of protein – many so-called “carnivore” dieters appear to thrive essentially on beef alone! Ribeyes, which have a wonderfully delicious blend of lean and fat, contain plenty of vitamin B12 and minerals like iron, zinc, selenium and phosphorus.
Chicken eggs are close to nature’s ‘perfect food’ as they might be the single best source of protein – and it’s not just the egg whites. There’s something about eating the whole egg that improves muscle protein synthesis better than eating the same amount of protein alone. Eggs are an excellent source of pantothenic acid and choline.
Full-fat dairy such as blue vein cheese has a respectable overall nutrient density score and is a great source of protein. Interestingly, its healthy fat profile and high levels of fat-soluble vitamin K2 are thought to be responsible for full-fat dairy’s apparent protection from heart disease.
We’ve all heard that we should be eating more seafood, so it should come as no surprise to hear that fish like salmon are near the top of the nutrient-density charts. Salmon, one of the most popular varieties of rich, fatty fish, is a great source of the active forms of omega-3s (DHA and EPA). It also has lots of the active form of vitamin D3 (cholecalciferol), which helps maintain overall good health and strong bones. Other vitamins found in salmon are B3 (niacin), B5 (pantothenic acid) and B6 (pyridoxal 5’-phosphate).
Shellfish are also replete with nutrients. Clams are another excellent source of complete protein, and are rich in minerals like selenium, zinc and contain a lot of cobalamin (vitamin B12). Like many shellfish, they have a slight carbohydrate content, about 6 g of carbs for 10 small clams, a sizeable helping.
3. Green leafy vegetables, fruit and legumes
There’s a big drop in the average nutrient density of foods from group #2 to group #3.
Why do animal foods dominate the top of the list? This actually makes sense: animals harvest the nutrients from their food and masterfully concentrate them in their own bodies, converting nutrients from plants (and bacteria!) into their active forms. Also, animal foods are mostly made from the essential macronutrients fat and protein. Carbohydrate, the third macronutrient, is not actually essential. Animal foods also contain virtually all the essential micronutrients humans require to live.
Plant foods can certainly fit into a healthy, nutrient dense diet, although on their own (as in vegan diets) supplements become crucial. In practice it’s difficult to eat enough of even the most nutritionally dense vegetables, because they contain comparatively so little energy and nutrition in each mouthful.
Leafy green vegetables tend to contain the most nutrients, pound for pound, in virtue of being very low calorie. Kale contains quite a bit of the mineral manganese and vitamin C, both of which are hard to find in animal foods. Avocados are rich in the mineral potassium which helps normalize blood pressure, as well as vitamin B5 (pantothenic acid). Although avocados are known for their vitamin E content, it’s mostly in the inactive form (?-tocopherol). Only a small fraction can be converted into the active form (?-tocopherol).
You might be surprised to see that fruits are generally less nutritionally dense than commonly supposed. Typically, it is the less sweet fruits that are closer to their natural wild forms that pack in the most nutrients: blackberries and raspberries are good examples. Lemons are also a very low-sugar fruit, with lots of vitamin C.
Legumes aren’t good low-carb options, generally speaking, because of their high carbohydrate content. With some portion control, however, they can be incorporated into a healthful lower-carbohydrate diet. Consuming them after meat and greens lowers glycemic excursions and can be a helpful technique for managing postprandial blood sugar levels.
One thing to note about legumes is that they contain a large number of anti-nutrients. Anti-nutrients are plant compounds that inhibit they body’s ability to absorb essential nutrients such as zinc, magnesium, potassium, iron and calcium. Because a typical nutrient density score does not factor in the effect of anti-nutrients, legumes may realistically be less nutrient dense than the Nutrition Facts label would have you believe.
The Least Nutritious Foods
The worst offenders are added sugar, flours, and high omega-6 seed oils. They should be avoided for three reasons.
First, they have terrible nutritional profiles, and are truly lacking in important micronutrient content. Flour, for example, needs to be fortified in order to avoid frank nutrient deficiencies. Second, they take up a large percentage of calories in the average diet and thus usually displace more nutrient dense options. Third, they interfere with normal metabolic responses and commonly induce chronic inflammation.
By eliminating the least nutritious foods, and focusing on nutrient-dense options, you increase your odds of being nutritionally sufficient. Fueling your body with what it needs while avoiding blood sugar swings is a win for diabetes management.