What will happen if I only eat one egg a day?

October 25, 2025 •

4 min read

An estimated 96 billion eggs were consumed in the US in 2023, with many people incorporating them into a daily routine. We examine exactly what will happen if I only eat one egg a day, detailing the benefits and significant drawbacks of this extremely restrictive eating pattern.

Quick Summary

Eating one egg daily provides high-quality protein and essential vitamins, but a diet restricted to this item alone causes major nutrient deficiencies and health risks.

Key Points

Nutrient Boost: Eating one egg provides high-quality protein, choline for brain health, and essential vitamins like D and B12.
Significant Gaps: A diet of only one egg severely lacks fiber, vitamin C, and many minerals, leading to nutritional deficiencies.
Cholesterol Impact: For most healthy individuals, a single daily egg does not negatively affect blood cholesterol, but those with heart disease should be cautious.
Feeling Satiated: The protein content of an egg can increase feelings of fullness, helping with weight management within a balanced diet.
Balanced Approach is Key: Eggs should be one part of a varied diet; relying solely on them leads to fatigue and health risks.
Cooking Matters: The healthiest ways to eat an egg are boiling or poaching, as frying adds unnecessary fat and calories.

The Immediate Impact: Nutritional Boost

On its own, a single large egg is a nutritional powerhouse, providing a significant amount of high-quality protein and a variety of essential vitamins and minerals. The contents of one large egg, at around 72 calories, offer a solid starting point for nutrition but are far from a complete meal.

The Positive Effects of Daily Egg Consumption

For a healthy individual, adding one egg a day to a balanced diet offers several benefits:

High-Quality Protein: An egg provides about 6 grams of protein, containing all nine essential amino acids needed for muscle repair, growth, and overall body function.
Brain Health: The yolk is a rich source of choline, a vital nutrient for brain health, memory, and nervous system function.
Eye Health: Eggs contain the antioxidants lutein and zeaxanthin, which help protect your eyes against macular degeneration and cataracts.
Essential Vitamins and Minerals: Eggs are one of the few natural food sources of Vitamin D, and they also supply significant amounts of Vitamin B12, selenium, and iron.

The Negative Consequences of a Restricted Diet

While one egg is a nutrient-dense food, eating only one egg a day is not a sustainable or healthy diet. The body needs a wide range of nutrients from various food groups to function correctly, and a single egg cannot provide this diversity.

Significant Nutrient Deficiencies

By restricting your diet to a single egg, you will quickly develop severe deficiencies that lead to health problems. The most prominent missing nutrients include:

Fiber: Essential for digestive health and preventing constipation, fiber is completely absent in eggs.
Vitamin C: Crucial for immune function, skin health, and tissue repair, this vitamin is not found in eggs.
Calcium: Important for bone health, calcium is present in eggs but in insufficient quantities to meet daily needs.
Complex Carbohydrates: Your body's primary source of energy will be completely lacking, leading to fatigue and poor performance.
Micronutrients: Many other vitamins and minerals, such as Vitamin K, magnesium, and potassium, will be missing, causing systemic issues over time.

The Impact on Cholesterol and Heart Health

For many years, the cholesterol in eggs was a major concern for heart health. However, recent research shows that for most healthy adults, dietary cholesterol has a minor impact on blood cholesterol levels compared to saturated and trans fats. Still, eating only eggs can still present risks for some individuals.

Comparison: One Egg Diet vs. Balanced Diet

To highlight the limitations of a single-egg diet, here is a comparison of the key nutritional components.


Feature	One Egg Diet	Balanced Diet	Notes
Macronutrients	Very low calories, limited protein, moderate fat.	Appropriate balance of calories, protein, carbs, and fats.	An egg alone is not enough for daily energy needs.
Micronutrients	Deficient in most vitamins (C, K), minerals (calcium), and fiber.	Rich in a diverse range of vitamins and minerals.	Variety ensures all nutritional needs are met.
Satiety	Protein offers temporary fullness, but constant hunger follows.	Combination of protein, fiber, and carbs sustains energy.	Restrictive diets often lead to excessive hunger.
Long-Term Health	Severe deficiencies, risk of chronic disease, fatigue.	Optimal body function, reduced risk of deficiencies.	The key is variety and moderation.
Sustainability	Not sustainable; will lead to health deterioration.	Sustainable and promotes long-term well-being.	A single-food diet is a path to malnutrition.

Beyond the Single Egg: Building a Balanced Diet

To leverage the benefits of eggs without risking severe malnutrition, it is crucial to incorporate them as part of a varied and balanced diet. Consider pairing a single egg with other healthy foods to create a more complete meal.

Suggestions for Balanced Meals:

Combine your egg with low-carb vegetables like spinach, peppers, and onions in an omelet for added fiber and vitamins.
Serve a poached egg on whole-grain toast with avocado for a combination of healthy fats, fiber, and complex carbohydrates.
Add a hard-boiled egg to a salad filled with leafy greens and other colorful vegetables to boost your protein and add nutrients.

By following a sensible diet and incorporating regular physical activity, you can enjoy the many health benefits of eggs without experiencing the severe risks of nutritional deprivation. For further guidance on healthy eating patterns, a registered dietitian can provide personalized advice.

Conclusion

While a single egg is packed with valuable nutrients like high-quality protein, choline, and Vitamin D, attempting to subsist on only one egg a day is extremely unhealthy and unsustainable. This severely restrictive diet will inevitably lead to significant nutritional deficiencies, such as a lack of fiber, Vitamin C, and calcium, causing long-term health problems. Eggs should be viewed as a single, valuable component of a varied and balanced dietary plan, not as a complete meal replacement. For most healthy adults, enjoying one egg daily as part of a diverse diet is safe and beneficial for overall wellness. Read more on how many eggs are safe to eat from Healthline.

Frequently Asked Questions

No, eating only one egg a day is not enough. While an egg is nutrient-dense, it lacks many essential nutrients like fiber, Vitamin C, and carbohydrates, leading to severe nutritional deficiencies over time.

For most healthy individuals, eating one egg per day does not significantly raise blood cholesterol. However, those with pre-existing heart conditions or diabetes should consult a healthcare professional to monitor their intake.

While an egg is relatively low in calories and high in protein, a single-egg diet is extremely low-calorie and unbalanced. Any weight loss would be unhealthy and unsustainable, likely resulting in rebound weight gain.

Without fiber, you will likely experience digestive issues like constipation. Fiber is also important for heart health and blood sugar regulation, all of which would suffer on this restrictive diet.

To create a balanced meal, pair your egg with vegetables, a source of complex carbohydrates like whole-grain toast or quinoa, and healthy fats like avocado or olive oil.

Egg whites offer protein without cholesterol, but you lose many essential nutrients like choline, vitamin D, and antioxidants found in the yolk. Eating the whole egg is generally recommended for healthy individuals.

Yes, individuals with diabetes, high LDL cholesterol, or a familial history of heart disease should be more cautious and may need to limit whole egg intake further, as advised by their doctor.