Eating nothing but eggs would keep you alive for a while, but it would eventually make you seriously ill. Eggs are surprisingly nutrient-dense, covering most vitamins and minerals your body needs, but they’re missing a few critical ones. The biggest threat is scurvy: eggs contain zero vitamin C, and clinical symptoms of deficiency can appear in as little as 8 to 12 weeks of going without it. Beyond that, an all-egg diet would leave you without fiber, overloaded on certain nutrients, and facing a growing list of problems the longer you kept it up.
What Eggs Give You (and What They Don’t)
Eggs are one of the most complete single foods available. The yolk contains every vitamin except vitamin C, along with meaningful amounts of iron, zinc, selenium, phosphorus, and choline. A single large egg delivers about 6 grams of protein with all nine essential amino acids, plus healthy fats and fat-soluble vitamins A, D, E, and K. Birds don’t need dietary vitamin C because they manufacture their own from glucose, which is why evolution never packed it into the egg.
The gaps are what would hurt you. Eggs have no fiber at all and almost no carbohydrates (about 0.7% by weight). They contain no vitamin C whatsoever. These aren’t minor footnotes. Fiber keeps your digestive system moving and feeds beneficial gut bacteria. Vitamin C is essential for collagen production, immune function, and iron absorption. Without external sources, your body’s reserves of vitamin C drain within weeks.
Scurvy: The First Real Danger
Vitamin C deficiency is the most predictable and dangerous consequence of an egg-only diet. Your body can’t make or store large amounts of this vitamin, so once your existing reserves run out, things deteriorate quickly. Early signs, appearing within the first month or two, include fatigue, general weakness, and irritability. These are vague enough that you might not connect them to diet.
By 8 to 12 weeks without vitamin C, full clinical scurvy can develop. At that point, symptoms become unmistakable: bleeding and swollen gums, easy bruising, small red or purple spots on the skin from broken blood vessels, joint and bone pain, poor wound healing, and corkscrew-shaped body hairs. Depression and mood changes are also common. Left untreated, scurvy is fatal. Historically, it killed thousands of sailors on long voyages before anyone understood citrus fruit was the cure.
Digestive Problems From Zero Fiber
Without any dietary fiber, constipation would become a near-immediate problem. Fiber adds bulk to stool and helps it move through the intestines. On an all-egg diet, you’d likely experience infrequent, difficult bowel movements within the first few days. Over weeks and months, chronic constipation can lead to hemorrhoids, anal fissures, and significant discomfort.
Fiber also plays a role in feeding the bacteria in your gut that support immune health, nutrient absorption, and even mood regulation. Starving those bacterial colonies by eating zero fiber could shift your gut microbiome in ways that compound other health effects.
Too Much Choline and Cholesterol
A single egg contains roughly 150 mg of choline. If you’re eating enough eggs to meet your daily calorie needs (somewhere around 14 to 18 eggs for most adults), you’d be consuming over 2,000 mg of choline per day. The tolerable upper limit for adults is 3,500 mg, so most people would stay under the danger zone. But push beyond that, and high choline intake causes a noticeable fishy body odor, excessive sweating and salivation, nausea, vomiting, and in extreme cases, drops in blood pressure and liver damage.
Cholesterol is a more nuanced concern. Meta-analyses of randomized controlled trials show that increased egg consumption raises both LDL (“bad”) cholesterol and HDL (“good”) cholesterol, with total cholesterol going up by about 5 to 6 mg/dL on average. The ratio between LDL and HDL tends to stay stable, which is somewhat reassuring. But those studies looked at people adding a few extra eggs to a normal diet, not people eating 15 or more per day with nothing else. At extreme intake levels, cholesterol effects are genuinely unknown, and individual responses vary widely.
TMAO and Long-Term Heart Risk
Eggs are rich in choline and lecithin, which gut bacteria convert into a compound called trimethylamine. Your liver then transforms it into TMAO, a metabolite linked to cardiovascular disease. A large study following nearly 6,800 adults over a median of 11 years found that higher TMAO levels were associated with heart disease risk in a dose-dependent pattern. People in the highest fifth of TMAO levels had a 33% higher risk of cardiovascular events compared to those in the lowest fifth, even after adjusting for other dietary and lifestyle factors.
On a normal diet with moderate egg consumption, TMAO production is manageable. But eating eggs as your sole food source would flood your system with choline-derived TMAO precursors day after day. The long-term cardiovascular implications of that kind of sustained exposure haven’t been directly studied, but the dose-dependent relationship suggests it wouldn’t be favorable.
Protein Overload and Kidney Strain
Eating 14 to 18 eggs daily means consuming roughly 85 to 110 grams of protein, well above the recommended 0.8 grams per kilogram of body weight (about 71 grams for an average-weight man). Healthy kidneys can handle elevated protein intake for a while, but chronically high protein consumption forces the kidneys and liver to work harder processing nitrogen waste. Your liver converts excess amino acids into urea and ammonia. Modeling studies show that increasing protein intake by 72% above recommended levels can raise blood ammonia by about 59%. For people with normal liver function, this stays within safe ranges, but anyone with even mildly compromised liver or kidney function could face dangerous ammonia buildup.
A Note on Raw vs. Cooked Eggs
If you were eating raw eggs specifically, you’d face an additional risk: biotin deficiency. Raw egg whites contain a protein called avidin that binds tightly to biotin (vitamin B7) and prevents your body from absorbing it. One documented case involved a patient who developed clinical biotin deficiency after eating six raw eggs daily for 18 months. Symptoms of biotin deficiency include hair loss, scaly skin rashes (particularly around the eyes, nose, and mouth), and neurological symptoms like numbness and tingling. Cooking eggs deactivates avidin, so this problem is specific to raw consumption.
What the First Weeks Would Actually Feel Like
In the short term, you’d probably feel surprisingly full. Eggs are highly satiating. Research on children and adolescents found that an egg-based breakfast increased levels of a fullness-signaling hormone called PYY by about 51% over three hours, compared to just 19% after a carbohydrate-heavy meal. You’d likely lose weight initially because it’s hard to eat enough eggs to match your typical calorie intake, and the high protein content keeps hunger in check.
But fullness isn’t health. Within a few days, constipation would set in. Within a few weeks, energy levels would start to drop as vitamin C reserves dwindled. By two to three months, you’d be dealing with symptoms of scurvy. The monotony alone would become psychologically difficult, and the lack of carbohydrates would force your body into ketosis, burning fat for fuel, which can cause bad breath, headaches, and brain fog in the transition period.
Eggs are an excellent food. They’re just not a complete one. The nutrients they’re missing happen to be the ones whose absence causes the most dramatic and rapid consequences.