What Is the Single Most Nutritious Food You Can Eat?

If you could eat only one food for the rest of your life and still meet most of your nutritional needs, what would it be? The quest to find the most nutritious food on the planet has fascinated scientists, dietitians, and health enthusiasts for decades. In this comprehensive guide, we break down what research says about the single most nutrient-dense food and why it earns the top spot.

Understanding Nutrient Density: How Scientists Rank Foods

Before we reveal the answer, it helps to understand how researchers measure nutritional value. Nutrient density refers to the amount of essential vitamins, minerals, and beneficial compounds a food delivers per calorie. The higher the ratio of nutrients to calories, the more nutrient-dense the food is considered.

Dr. Jennifer Di Noia of William Paterson University published a landmark study in the journal Preventing Chronic Disease that ranked 41 fruits and vegetables by nutrient density. Her research used 17 nutrients recognized as critical for public health, including potassium, fiber, protein, calcium, iron, and vitamins A, B6, B12, C, D, E, and K.

Other ranking systems, such as the Aggregate Nutrient Density Index (ANDI) created by Dr. Joel Fuhrman, evaluate foods on a scale of 1 to 1,000. These tools give us a data-driven way to compare foods objectively rather than relying on marketing claims or food trends.

The Healthiest Food in the World: Why Liver Tops the List

When all nutrients are considered — not just vitamins from plants but also bioavailable minerals, complete protein, and fat-soluble vitamins — beef liver consistently emerges as the single most nutritious food available. A 100-gram serving of cooked beef liver delivers staggering quantities of essential nutrients:

• Vitamin A (retinol): over 700% of the daily value — the most bioavailable form
• Vitamin B12: over 1,400% of the daily value — critical for nerve function
• Riboflavin (B2): over 200% of the daily value
• Folate: 65% of the daily value — essential for cell division
• Iron (heme): 36% of the daily value — far more absorbable than plant iron
• Copper: over 700% of the daily value
• Choline: 85% of the adequate intake — vital for brain health
• Complete protein: 26 grams of high-quality protein with all essential amino acids

No single plant food can match this breadth of nutrients in one serving. While leafy greens like watercress and kale score extremely high among vegetables, they lack vitamin B12, heme iron, and complete protein — nutrients that liver provides abundantly.

The Most Complete Food: Nutrient-Dense Alternatives

If organ meats are not your preference, several other foods rank exceptionally high for nutrient density. Understanding these alternatives helps you build a diet rich in the most complete food sources available.

Salmon and Sardines

Fatty fish like wild-caught salmon and sardines offer omega-3 fatty acids (EPA and DHA), vitamin D, selenium, and high-quality protein. Sardines eaten with bones also provide significant calcium. A 2024 meta-analysis in The American Journal of Clinical Nutrition confirmed that two servings of fatty fish per week reduce cardiovascular mortality by 17%.

Eggs

Often called nature's multivitamin, a single large egg contains 13 essential vitamins and minerals, including choline, selenium, B12, and vitamin D. The yolk is where most of the nutrition resides, so eating whole eggs matters.

Kale and Watercress

Among plant foods, watercress scored a perfect 100 on Dr. Di Noia's nutrient density scale, followed closely by Chinese cabbage, chard, and beet greens. Kale remains a superfood nutrition powerhouse thanks to its high levels of vitamins K, A, and C, plus antioxidants like kaempferol and quercetin.

Sweet Potatoes

One medium sweet potato provides over 400% of your daily vitamin A (as beta-carotene), plus fiber, potassium, and manganese. They are also one of the most affordable nutrient-dense foods worldwide.

Nutrient Density Ranking: Top 10 Foods Compared

To give you a clear picture, here is a nutrient density ranking based on composite scores from multiple scientific sources:

1. Beef liver — unmatched in B12, vitamin A, iron, copper, and choline
2. Sardines (whole) — omega-3s, calcium, D, B12, and selenium
3. Watercress — highest-scoring vegetable for vitamins and minerals per calorie
4. Wild salmon — omega-3s, astaxanthin, D, and protein
5. Kale — vitamins K, A, C, and powerful antioxidants
6. Eggs (whole) — complete protein, choline, D, and B12
7. Spinach — iron, folate, K, and magnesium
8. Sweet potatoes — beta-carotene, fiber, potassium
9. Blueberries — anthocyanins, vitamin C, manganese
10. Lentils — plant protein, folate, iron, and fiber

This ranking considers bioavailability, meaning how well your body can actually absorb and use the nutrients, not just the raw amounts listed on a label.

Common Myths About Superfood Nutrition

The wellness industry is full of misleading claims about superfood nutrition. Here are some myths worth correcting:

Myth 1: One superfood can replace a balanced diet

No single food, not even liver, contains every nutrient in ideal amounts. Vitamin C, for example, is low in liver but abundant in fruits and bell peppers. A diverse diet always outperforms any single-food strategy.

Myth 2: Expensive exotic superfoods are more nutritious

Acai bowls and goji berries are trendy, but common foods like eggs, sardines, and sweet potatoes deliver comparable or superior nutrition at a fraction of the cost. Marketing drives perception more than science does.

Myth 3: Plant-based diets cannot be nutrient-dense

While liver is the single most nutrient-dense food, a well-planned plant-based diet incorporating legumes, leafy greens, nuts, seeds, and fortified foods can meet virtually all nutritional needs. The key is variety and attention to B12, iron, and omega-3 supplementation.

How to Add More Nutrient-Dense Foods to Your Diet

Knowing the healthiest food in the world is only useful if you actually eat it. Here are practical tips to boost your nutrient intake starting today:

• Start with eggs at breakfast — scrambled, poached, or in an omelet with spinach and bell peppers
• Eat sardines twice a week — on toast with lemon, in salads, or straight from the tin
• Add a handful of kale to smoothies, soups, or stir-fries daily
• Try liver pate — a gentler introduction to organ meats, spread on whole-grain crackers
• Swap white potatoes for sweet potatoes — baked, mashed, or roasted with olive oil
• Keep frozen blueberries in your freezer for quick additions to yogurt or oatmeal

Small, consistent changes matter far more than dramatic dietary overhauls. Aim to include at least three foods from the top-10 list in your meals each day.

Conclusion: The Most Nutritious Food Is Closer Than You Think

Science consistently points to beef liver as the single most nutritious food available, packing extraordinary amounts of vitamin A, B12, iron, copper, and choline into a small serving. However, the real lesson is broader: nutrient density should guide your food choices more than calorie counts or trendy labels.

Whether you embrace organ meats or prefer a combination of salmon, eggs, kale, and lentils, prioritizing nutrient-dense foods is the most impactful change you can make for long-term health. Start with one swap this week, and build from there.

FAQ: Frequently Asked Questions

What is the single most nutritious food?

Beef liver is widely considered the single most nutritious food. It provides exceptionally high amounts of vitamin A, B12, iron, copper, choline, and complete protein per serving.

What is the most nutritious vegetable?

Watercress scored a perfect 100 on Dr. Di Noia's nutrient density scale, making it the most nutritious vegetable. Kale, spinach, and chard also rank extremely high.

Can you survive on just one food?

No single food provides every essential nutrient in adequate amounts. While liver comes closest, it lacks sufficient vitamin C and fiber. A varied diet is always necessary for optimal health.

Are superfoods worth the cost?

Many affordable everyday foods like eggs, sardines, sweet potatoes, and kale are just as nutritious or more so than expensive exotic superfoods. Focus on nutrient density per dollar rather than marketing trends.

How many nutrient-dense foods should I eat daily?

Aim to include at least three to five nutrient-dense foods in your daily meals. Combining items from different food groups — such as leafy greens, fatty fish, eggs, and legumes — ensures broad nutritional coverage.