What three foods can you live on?

December 13, 2025 •

4 min read

Despite the common belief that humans need a wide variety of foods, records show people have survived for months on very restricted diets, sometimes on little more than water. While not medically recommended for long-term health, certain combinations of staple foods offer a surprising degree of nutritional completeness, raising the question of which three might suffice for survival.

Quick Summary

Analyzing the nutritional profiles of milk, potatoes, and a specific protein source reveals why this combination is often suggested for limited sustenance. Explores the importance of balancing macronutrients, vitamins, and minerals in a restricted food plan and the associated health risks of such a diet.

Key Points

Milk & Potatoes: Provide a foundational mix of carbs, protein, and essential vitamins like B12 and C, along with minerals such as calcium and potassium.
The Missing Link: A third food like salmon or quinoa is vital to supply complete proteins, essential fatty acids (omega-3s), and other micronutrients that milk and potatoes lack.
Risks Outweigh Benefits: Sustaining life on only three foods is possible in a survival scenario but carries serious long-term health risks, including severe nutrient deficiencies and organ damage.
Breast Milk's Completeness: For infants, human breast milk is the single most complete food, but no single food serves this purpose for an adult after weaning.
Hydration and Preparation: Proper hydration and cooking methods are crucial. Boiling potatoes, for instance, helps preserve nutritional value compared to frying.
Nutrient Diversity: A varied diet is essential for overall health and for obtaining all the required vitamins and minerals that a limited selection cannot provide.
Psychological Impact: Food restriction can lead to significant mental health challenges, including anxiety and disordered eating patterns.

The Three-Food Survival Trio: Milk, Potatoes, and a Protein Source

In extreme scenarios, the goal is not to thrive but to survive, making the choice of the most nutritionally complete and readily available foods crucial. Based on nutritional analysis and historical examples, a trio consisting of milk, potatoes, and a reliable protein source provides a surprisingly robust, albeit limited, diet for a time.

Milk: The Nutrient-Rich Base

Milk, especially whole milk, is a nutritional powerhouse. It provides a significant amount of complete protein, healthy fats, and a range of essential vitamins and minerals. Historically, human breast milk is considered the most complete single food for infants, and cow's milk offers a good, albeit less perfect, substitute for adults seeking a concentrated source of nutrients. Key benefits include:

Complete Protein: Contains all nine essential amino acids needed for tissue repair and growth.
Calcium and Vitamin D: Crucial for bone health, especially important in situations where sunlight exposure might be limited.
Vitamin B12: A nutrient vital for nerve function and blood formation that is often lacking in plant-based diets.

Potatoes: The Carbohydrate and Vitamin Source

The humble potato is more than just a source of carbohydrates; it is a vitamin-rich, nutrient-dense food that has sustained populations for centuries. As famously demonstrated by Andrew Taylor's year-long 'Spud Fit Challenge,' a person can survive on potatoes alone for an extended period, though not without serious health drawbacks. When combined with other foods, the potato provides:

Complex Carbohydrates: An excellent source of energy to fuel the body.
Potassium: An electrolyte essential for nerve and muscle function.
Vitamin C: A crucial vitamin for immune function and tissue repair, which can be scarce in a restricted diet.
Fiber: Important for digestive health.

The Third Food: A Complete Protein Source

While milk and potatoes offer a solid foundation, they do not provide all the necessary nutrients, particularly certain essential fatty acids and minerals. The third food is needed to fill these gaps. Two strong candidates are salmon and quinoa.

Salmon: A complete protein source rich in essential omega-3 fatty acids, which are critical for brain and heart health. The entire fish, including offal, can also provide trace minerals like iodine.
Quinoa: A complete plant-based protein alternative, also high in fiber and a range of minerals like magnesium, iron, and potassium. It is an excellent choice for those who cannot or do not consume animal products.

Nutritional Comparison of Potential Trio Elements


Feature	Milk (Whole)	Potatoes (Cooked)	Salmon (Cooked)
Macronutrients	Protein, Fat, Carbs	Carbohydrates	Protein, Essential Fats
Vitamins	B12, D, A, B2	C, B6, Folate	D, B12, Niacin
Minerals	Calcium, Phosphorus	Potassium, Iron, Magnesium	Iodine, Selenium, Potassium
Micronutrients Lacking	Iron, Fiber, Vitamin C	A, E, D, B12, Omega-3s	Vitamin C, Calcium
Primary Benefit	Complete protein & calcium source	Energy & essential vitamins	Complete protein & omega-3s

The Serious Health Risks of Restricted Diets

While these three foods can cover a surprising range of nutrients, living on such a restricted diet long-term is extremely dangerous and not recommended by health professionals. The body needs a diverse array of vitamins and minerals for optimal function, and a limited diet inevitably leads to deficiencies and health complications.

Nutrient Deficiencies: Long-term restriction often leads to deficiencies in vitamins A, E, K, and key minerals, which can cause severe health issues like weakened bones (osteoporosis) and vision problems.
Electrolyte Imbalances: Lack of variety can disrupt the body's delicate balance of electrolytes like sodium and potassium, potentially leading to heart complications and muscle cramps.
Muscle Wasting: Without sufficient caloric and protein intake, the body enters 'starvation mode' and begins breaking down its own muscle tissue for energy, including the heart muscle.
Mental and Emotional Toll: Restrictive eating can lead to disordered eating patterns, anxiety, and depression, as food becomes a source of stress rather than nourishment. The psychological impact of deprivation should not be underestimated.
Refeeding Syndrome: After a period of severe restriction, the body must be slowly and carefully reintroduced to food under medical supervision to avoid dangerous metabolic shifts known as refeeding syndrome.

Conclusion: Survival vs. Sustenance

Theoretically, a person could survive for a period on three specific foods like milk, potatoes, and a fatty fish or complete plant protein, given they are prepared correctly and in adequate amounts. This combination provides a solid foundation of protein, fats, carbohydrates, and several key micronutrients. However, it is crucial to understand that survival is not synonymous with health. For long-term well-being, the human body evolved to consume a varied, balanced diet rich in a wide spectrum of nutrients from different food groups. Relying solely on a limited trio, even a seemingly robust one, will eventually lead to severe nutritional deficiencies and serious health consequences. This is a topic of hypothetical interest, not a practical guide for a healthy lifestyle. For more information on the effects of severe caloric restriction, see the National Institute on Aging website.

Frequently Asked Questions

No, a human cannot survive indefinitely on only three foods. While survival for a short period is possible, a long-term restricted diet will inevitably lead to severe nutritional deficiencies and significant health problems that can be life-threatening.

A vegetarian version could potentially use milk, potatoes, and quinoa to cover essential nutrients. For a vegan diet, using potatoes, quinoa, and a nutrient-dense green like kale or spinach could be an option, though it would require careful planning to ensure all nutrients, especially B12, are met.

No, the 'Spud Fit Challenge' was not a healthy demonstration of a long-term diet. While the participant survived and lost weight, such a restrictive diet poses significant health risks due to the lack of essential nutrients found in a balanced diet. Medical professionals do not recommend this approach.

Even with a seemingly complete trio, key nutrients like vitamins A and E, certain minerals, and specific fatty acids may still be lacking, leading to potential health issues over time. Proper hydration with clean water is also crucial and separate from the foods themselves.

After a period of severe restriction or starvation, reintroducing food must be done slowly and under strict medical supervision. This prevents refeeding syndrome, a dangerous condition caused by sudden metabolic shifts, electrolyte imbalances, and fluid retention.

Other combinations suggested hypothetically include salmon, spinach, and whole white milk, or fish, eggs, and potatoes. The key is to combine a source of complex carbs, a complete protein, and a leafy green or nutrient-rich dairy item to balance the nutritional profile.

The psychological effects can be significant and include feelings of guilt, low self-esteem, anxiety, and an increased risk of developing eating disorders. Constant food restriction can lead to a negative relationship with food and may cause social isolation.

A varied diet is essential because different food groups provide unique vitamins, minerals, and other compounds that the body needs for optimal function. Without this diversity, a person cannot maintain long-term health and is at high risk for developing nutritional deficiencies.