I want to preface this blog, with a little reminder. Any tidbit of advice or perspective I offer, I would encourage you to always reflect on how it makes YOU feel. The best thing you can do when reading or hearing any information (especially nutrition information) is to always experiment with how it impacts you and your life. Remember we all have very unique health history's and relationships with food and exercise. Reflect, experiment, reflect and make your call.
Today, I’m going to discuss why I stopped throwing out my egg yolks and started enjoying them.
From 2009-2013, I was encouraged to ONLY eat egg whites for it’s high protein, low fat and no carb content. I was lead to believe that the yolk was “unhealthy” (aka too high in fat) and as a result would stall my fat loss progress. As early as 1973, many doctors started to prescribe, “reducing the amount of eggs (specifically the yolk)” because it led to elevated cholesterol levels. I’d like to provide a different perspective on eggs that may help you reconsider your egg consumption.
I just want to talk a bit about cholesterol. So, What is cholesterol?
“Cholesterol is a waxy, fat-like substance that's found in all the cells in your body. Your body needs some cholesterol to make hormones, vitamin D, and substances that help you digest foods.” - NIH
Yes, eggs contain cholesterol, roughly 200mg, but if we explore cholesterol more thoroughly we notice that eggs actually contain a very minimal amount of the bad cholesterol, making the argument that they raise cholesterol levels a bit faulty.
What's more important to look into is the ratio of bad (LDL, low density lipoprotein) versus good cholesterol (HDL, High density lipoprotein). Whole egg consumption, actually contributes positively to improved lipid levels. Therefore, even if the overall cholesterol levels increase the actual increase improves your lipid profile! So keep in mind, cholesterol is made up of HDL, LDL and VDLV (very low density lipoprotein). When people often discuss, “bad cholesterol”, they’re more so referring to LDL and VLDL. Both of which are more commonly a result of genetics, weight, ethnicity (ex. African Americans), activity and diet (ex. corn-fed meats, canola oils). Please check the reference section I linked below that discusses this further.
When we look at egg whites, we're also analyzing other properties, amino acids.
Methionine, is an essential amino acid, needed for cellular growth and development. However, just like everything we do, over consumption of methionine can elevate inflammation. Remember, chronic inflammation can result in a series of adverse effects like weight gain, pain, GI discomfort etc. Methionine when consumed in larger quantities (that of which is self determined), is also known for its thyroid suppressing properties. Those of you who have experienced issues with your thyroid like extreme fatigue, consistent and often unexplainable weight gain, GI distress and a slower metabolic rate may want to keep an eye on how many meals you consume that are strictly just egg whites.
The whites, also contain tryptophan. When tryptophan is consumed in larger quantities, it can result in a slower metabolic rate, sluggish metabolism, increase in inflammation, depression and fatigue.
Research on cysteine has also been shown to inhibit the production of T4 (Thyroxine), which is one of the thyroid hormones to be tested if you suspect you are struggling with a sluggish thyroid.
Therefore, egg whites when consumed in large amounts and alone (without the yolk) is when we start to notice more of these adverse effects. Having a fast metabolism is more than just eating high protein foods. It's about giving our bodies quality! Yes, egg whites are a great protein source, but the yolk is where all the nutrient benefits lie.
Take a look at the graph below, you can start to gain more insights into why the yolk may be beneficial.
For many women, myself included, removing the fat content from my diet (that of which included the egg yolks) and drastically increasing the protein intake (egg whites) resulted in an imbalance, which included a loss of my menstrual cycle and a host of other thyroid suppressing symptoms like reduced body temp, constipation, bloat, fatigue, irritability, and mood swings. Having a thriving metabolism is often less about calories and more about nutrients.
I also want to make note, that the quality of your eggs does matter. According to Kate Deering, in her book "How to Heal Your Metabolism" she discusses the best to worse egg choices:
Best to Worse:
1. Pasturized, organic, no soy, no corn fed Eggs
2. Organic free roaming, vegetarian-fed Eggs
3. Free Roaming Eggs
4. Cage Free Eggs
5. Natural Eggs
6. Conventionally Farmed eggs
So the next time you head to a grocery store, try to aim for quality egg sources, farmed and raise locally from chickens allowed to roam outside of confined spaces. Their diets are free of hormones and antibiotics. They may be hard to find, especially depending on where you live, but completely worth the investment (note, the yolks are actually a bright, vibrant orange, than a clear/pale yellow).