Eggs: What's True, What's a Myth, and Who Should Avoid the Yolk

Chicken egg white is the reference point for protein quality. When scientists measure protein bioavailability across different foods, egg white is used as the benchmark — set at 100%. Everything else is measured against it. Soy protein clocks around 40%. Whey protein concentrate usually measures at 80-90%.

The BCAA ratio of 2:1:1 (leucine, isoleucine, valine) comes from egg white protein — it reflects the proportion of branched-chain amino acids found in one of the highest-quality protein sources humans consume.

Should You Eat Egg White Raw or Cooked?

Cooked, always. Raw egg white contains a substance (avidin, plus compounds that interfere with digestive enzymes) that significantly impairs protein absorption. Cooking denatures these compounds, making the protein fully available.

The colour change when egg white cooks is protein denaturation — a physical structural change. The amino acid composition itself is unaffected. The protein is just as complete and bioavailable after boiling as before — more so, in fact.

The Yolk Question

The yolk contains cholesterol, fat, and additional micronutrients. Whether you should eat it comes down to your current metabolic state.

If you're healthy and not carrying excess body fat: eat whole eggs. There's no evidence of harm for metabolically healthy people. Factor the yolk's fat content into your macros if you're tracking, and move on.

If you have excess body fat (especially combined with insulin resistance): skip the yolk. Not because cholesterol in food is inherently dangerous — the relationship is more complex than that. But if you're in a caloric deficit and trying to reduce body fat, you have no reason to add extra fat intake through yolks. The protein in the white is what you need; the fat in the yolk isn't contributing to your goal.

If you have diabetes or diagnosed atherosclerosis (clogged arteries): avoid the yolk. Studies specifically show that regular yolk consumption increases cardiovascular event risk in this population. This is not a controversial finding — it's consistent across the literature.

Practical Summary

Egg white: eat it, always cooked, as much as your protein goals require. One of the cheapest and best quality protein sources you can get.

Egg yolk: fine if you're healthy and not overweight. Skip it during fat loss phases. Avoid it if you have diabetes or cardiovascular risk.

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