Sometimes I feel as though I’ve entered a bizarro world of nutrition. Much like Superman’s Bizarro World or The Bizarro Jerry episode of Seinfeld, everything seems to run counter to what I once believed. Fat is good, whole grains are bad, and calories don’t matter.
Here are seven nutrition myths I once thought were true:
1. Eat a low-fat diet
Back in the day, this made so much sense. Fat is bad and if you don’t want to be fat, don’t eat fat! Just live on a boat-load of plain chicken breast salads and boom! Problem solved! Sorry, but this is completely wrong.
Fat doesn’t make you fat, carbs do. Consuming carbs triggers the production of a hormone called insulin. One of the main roles of insulin in your body is fat storage. Insulin deposits the unused glucose from carbs into fat cells for later use making you fat. The fewer carbs you eat, the lower your insulin levels will be, and the less glucose you’ll store.
2. Cholesterol clogs your arteries so stay away!
Eggs, shrimp, and red meat. These are some of the foods classically fingered as heart attack makers. Shrimp is one of the worst offenders, sending 63% of your USDA recommended daily allowance of cholesterol directly to your heart’s blood vessels. Yikes! Eggs aren’t too far behind at 62%.
But, guess what? It’s all wrong! Cholesterol is actually good for you. Your body uses it to make vitamin D and hormones such as testosterone and estrogen. In fact, we don’t eat enough! We typically only eat 20% of what your body needs. Thankfully, your liver steps in to make up the difference.
I know what you’re thinking:
“My doctor says I have high cholesterol. It’s gotta be bad.”
Perhaps he’s not aware that the typical cholesterol test is flawed. The standard lipid profile doesn’t actually measure cholesterol levels. Instead, it measures the number of shipping containers, called lipids, in your blood. These lipids transport cholesterol, among other things, through your body. High-density lipids (HDL) are good and a high count of low-density lipids (LDL) is considered bad.
Here’s the tricky part. A standard lipid profile measures the number of LDL particles, but researchers are finding that it’s actually the size of these particles that matters more than the count when it comes to risk for heart disease. To measure the size, you can request the newer NMR test or you can simply divide your triglycerides by your HDL. If the result is less than 1.3, your LDL particles are likely big and fluffy, which is good. You have a low risk for cardiovascular disease.
TG/HDL < 1.3 ⇒ good
3. Eat lots of whole grains
Just scarf down a bunch of bran flakes or Cheerios and all the fiber will flow like Drano through your arteries scrubbing them clean. At least that’s the impression I’ve been living under for most of my life. I now realize it’s wrong.
While it’s true that “whole grains” have more fiber, your body still gets a pretty nice boost in blood sugar. It typically only takes 14 grams of carbs to spike insulin. And what does insulin do? It stores carbs as fat. You’re converting any unused grains directly into a beer belly.
Despite this, the USDA recommends most of your diet (around 60%) be composed of whole grains. The American Heart Association continues to maintain that whole grains are “heart-healthy“, granting qualified food packaging official-looking badges to lure the eye of unsuspecting shoppers.
4. Eat 6 times a day, or graze
It’s cracker time! The theory used to be, eat smaller meals more frequently to keep your metabolism elevated. Gotta keep that calorie burning engine chugging, right? Nope.
This theory doesn’t take insulin into account. By eating all the time, especially high-carb foods (like crackers), your insulin levels stay elevated and so your body is stuck all day in fat-storage mode.
Instead, eat 1-3 large meals within a short window of time. So spend at least 14 hours of the day not eating and the other 8 hours eating. This shorter feeding window allows insulin levels to sufficiently drop and your body can go into repair mode.
5. Eat lots of fruit; 2-4 servings a day
The message was always, “eat your fruits and veggies!” The implication being that fruits and veggies are all pretty much equal health-wise. If you don’t like broccoli, no big deal. Eat an apple or drink some OJ.
The problem is most fruits contain way more carbs than most veggies. More carbs mean a bigger insulin boost. Fruit juice is especially friendly to insulin because it doesn’t have the fiber normally found in fruit to slow down the sugar shock.
6. Stay away from salt!
The message goes something like:
“Consume as little sodium as possible to avoid high blood pressure.”
But, your body needs a minimum amount of sodium to function properly. Sodium keeps your muscles firing, your heart pumping, your digestive system churning, and your cells hydrated. Too little sodium and you die. In fact, marathoners are susceptible to a sometimes fatal condition known as hyponatremia. It’s an imbalance caused by drinking too much water after sweating out tons of sodium.
There’s research to suggest that too much sodium is not as dangerous as too little, especially if you workout regularly and eat a high-fat diet. We lose salt when we sweat, and lower insulin levels actually mean you lose more salt than you might on a low-fat diet.
Past studies that have tried to draw a link between sodium intake and high blood pressure ignore the fact that healthy kidneys have the ability to regulate a wide range of sodium intake to keep the body in a balanced state. These studies also ignore the effects of other minerals such as Potassium and Magnesium on blood pressure. Is it a coincidence that the DASH diet, a low salt diet typically recommended for those with high blood pressure, is also higher in potassium and magnesium?
7. If you’re too fat, just eat fewer calories
Chances are you’ve seen people who look overweight or obese as in the picture above. You might think to yourself:
“What’s wrong with them?! Why don’t they just eat less?!”
After all, a calorie is a calorie, whether it comes from a donut or a lettuce leaf, right? That’s what I used to think.
Metabolism is much more complex than the simple calorie-in, calorie-out story we’ve been hearing for so long. Hormones play a much bigger role than previously thought in how your body process food. Some people have different levels of hormones, mainly insulin, that determine how the body stores or burns different foods. This explains why some people seem to eat everything in sight and not gain a pound, while others blow up like a balloon when they smell a raisin.
I could probably think of a few more, but seven seems like a good number.