Those who know me well know that I’ve followed a lot of weird diets over the years. I’ve tried going vegan, I was vegetarian for a year, I’ve flirted with the ketogenic (aka keto) lifestyle, and I even tried Atkins when I initially lost 40 pounds at the age of 18. Now that I’m in my late 20s, I can officially say that I’ve been researching health and nutrition for a full 10 years. It’s my passion. And that’s why I’ve turned health writing into a career.
My health writing career has exposed me to numerous points of view, but at the end of the day, it’s extremely clear to me what the healthiest diet is for human beings: A high-fat, low-carb approach.
Of course, there are some caveats. I don’t believe in bombarding your body with butter, cheese, bacon and other processed foods, as is characteristic of a ketogenic diet. I do believe in nourishing your body with healthy carbs, such as fruits and sweet potatoes. But overall, modern science tells us that eating a minimal amount of real-food carbohydrates, a moderate amount of protein from free-range animal meats, and an abundance of healthy fats from nuts, seeds, avocados, animal fats and extra-virgin oils is the way to go. Here are the reasons why.
So, right off the bat, an easy one: Fats are naturally satiating. This is why after a heavy meal, you tend to feel full, happy and satisfied, whereas if you spring for a low-fat, high-carb meal, you may feel full initially, but you eventually experience hunger cravings and an energy crash (more on that later).
When you eat low-fat, your body constantly craves more, and it can be difficult to stick to a healthy eating style. Add more healthy fats into your meals, and you will find that you experience increased satisfaction at the end of your meals.
Fats Build Your Hormones
This one is particularly important to me as a woman. Fats (along with proteins) are the building blocks of hormones. This is why many women who eat low-fat experience amenorrhea, the loss of their period. It’s also one of the reasons why Paleo and ketogenic diets are correlated with improved skin for sufferers of hormonal acne, why they aid in the treatment of PCOS (polycystic ovary syndrome) and why many menopausal women feel better after switching to a high-fat, low-carb diet.
Carbohydrates Require Insulin Production
I’m not saying that people shouldn’t eat carbohydrates. Carbohydrates contain glucose, a type of sugar molecule, that the body prefers as a fuel source. When you eat carbohydrates, your body uses glucose first, and then after all of that glucose has been exhausted, it moves into fat-burning mode (using fat as fuel, producing ketones in the process). It is healthy to consume carbohydrates, but the modern diet contains far too many carbs. As a result, we are seeing rates of Type 2 diabetes skyrocket.
When you consume glucose, your body must release insulin in order to shuttle the glucose into your cells and use it for energy. This is all well and good, but when you’re in this state constantly, it starts to take higher and higher amounts of insulin to get the job done. This is called insulin resistance, and is a precursor to Type 2 diabetes.
Now back to that topic I mentioned earlier: Energy crashes. When we become dependent on glucose as our primary fuel source, the body becomes unaccustomed to fat burning and craves carbohydrates constantly. We begin to experience energy crashes as well as carbohydrate and sugar cravings, leading us to believe we need to eat round-the-clock to feel satisfied.
Gluten is Inflammatory
This one is contentious, because a lot of people get very defensive about gluten. Gluten is a sticky protein found in certain types of grains, such as wheat, barley and rye. Keep in mind that until relatively recently in human history, our ancestors didn’t have the knowledge or ability to farm crops. Things like grains that need to be processed in order to be fit for consumption are not a part of our natural diet.
Some people have Celiac disease, which means they can’t eat gluten at all. But even the rest of us still have some cause for concern. Dr. David Perlmutter’s book “Grain Brain” (keep reading for the link!) is a great read that fully explains the gluten issue. To summarize: It’s scientific fact that eating gluten produces a state of mild inflammation in the body, and inflammation is now suspected to be the real culprit behind chronic diseases like Alzheimer’s, heart disease, cancer, depression, arthritis…. Pretty much everything.
As a side note, if you go to the Field Museum in Chicago, take a look at the Ancient Americas exhibit. There’s a sign that talks about how no evidence of chronic disease shows up in the human fossil record until after the Agricultural Revolution (aka, the time period when we started eating grains). This totally blew my mind! I guess the Field Museum has been covering the gluten issue since before it was cool.
Animal Products Are Extremely Nutritious
Look, I hate animal cruelty as much as the next person, but even as a former vegetarian/sometimes vegan and a health writer, I have to admit that eating meat is simply better for the human body nutritionally. Vegan diets are deficient in vitamin D, vitamin K12, vitamin B12, iron, cholesterol (again with hormone health) and vitamin A (no, you can’t get vitamin A from carrots — you can get betacarotine, which may be converted to vitamin A in the body, but the pathways are very inefficient). For a great summary of why I believe eating animal products to be beneficial for good health, check out this article.
All that said, I do think it’s possible to thrive on a vegan diet if you’re really meticulous about your nutrients and don’t mind eating soy products or tons of beans/legumes. But you can see more of my thoughts on that here.
Your Body Is Meant to Shift Between Glucose-Burning and Fat-Burning
So, I mentioned earlier that your body burns glucose before turning to fat. Many people associate fat-burning mode with starvation simply because the body metabolizes glucose first, but actually, these two mechanisms are both important for good health.
Moving into ketosis (“fat-burning mode,” where your body burns through its fat stores and produces ketones in the process) happens whenever you sleep. It’s basically the body’s default way of getting energy when carbohydrates are not available, which in nature, they’re often not. And using fat for fuel has a lot of benefits. It delivers beneficial nutrients to the brain, helps with insulin resistance, helps keep your body fat percentage healthy (preventing extremely dangerous visceral fat from becoming a problem) and increases longevity.
Fats Are Good For Your Brain
Did you know that the reason older people tend to experience increases in cholesterol levels is because their body is trying to prevent cognitive decline as they age? That fact really boggles my mind. Cholesterol is absolutely beneficial for maintaining cognitive health. In addition to manufacturing your hormones, cholesterol is an important component of all the components that make up your brain.
There is a very clear correlation between the use of statins (medications that lower cholesterol) and dementia. This is so scary to me. If many modern studies are correct and it’s inflammation, not dietary cholesterol, that is behind dementia and other chronic diseases, we have a big problem. We are essentially living our lives eating inflammatory grains, and then decreasing our brain-protecting cholesterol levels even further by taking statins right when we need that cholesterol to keep our brains healthy. It’s no wonder deaths due to Alzheimer’s have increased by 89% since the year 2000.
Dietary Cholesterol Worries Are Probably A Myth
So, all the benefits of fats aside, what about the fear that dietary cholesterol and saturated fats can give us heart disease? Turns out, there wasn’t a clear correlation between the two to begin with, and now that we know how healthy fats are, scientists are starting to stop recommending that we avoid them.
For one thing, your genetics play a much bigger role in your cholesterol levels than the food you eat. Dietary cholesterol is now suspected to only minimally impact blood cholesterol, and it only seems to impact it at all if you already have a cholesterol problem. In fact, a recent government panel of scientists considered scrapping the US’s cholesterol guidelines altogether, stating that “Cholesterol is not considered a nutrient of concern for overconsumption.”
So, with all the benefits that fats seem to provide us, and considering that rates of heart disease, obesity, Alzheimer’s, depression and numerous other chronic conditions have only GONE UP since society started condemning fats, it seems silly to avoid them solely because of outdated science that was pretty suspect to begin with.
OK, whew, that was a long one. If you’ve read through to the end, congrats — I’m pretty passionate about this stuff and can get quite long-winded when it comes to nutrition. If you have any lingering concerns, here are some books and resources I’d definitely recommend as you consider what dietary choices to make for your health:
If you give these books a read, let me know what you think!
*Disclaimer: I’m not a Registered Dietician, I’m only describing what I’ve learned through 10 years of personal study on nutrition and through my career as a health writer. Don’t interpret any of this as medical advice — do what works for your body!