As a trainer, I'm constantly exposed to the ideas and misconceptions that people have about healthy eating. Most people get their nutrition information secondhand from a long line of misinterpreted data. Most of what we hear about nutrition is headline hype peddled by people who don't understand biology.
There is something seductive about the idea that you can avoid one thing, and the rest will magically fall into place. The truth, of course, is that paying attention to portions, eating vegetables, fruit, protein, getting enough sleep, and exercising regularly leads to good health. Unfortunately, the image of balanced meals and regular activity doesn't sell, so we fall for headline fads. Most nutrition myths contain a fragment of truth and have been misinterpreted. Let's take a look at some of the most common nutrition fallacies and find the truth.
10. To lose weight, you need to eat 5-7 meals per day.
In theory, eating more often would keep metabolism raised, but in practice this doesn't equal more weight lost. This myth came from the idea that being hungry sends your body into “starvation mode” and therefore signals it to hold on to fat. This is actually the opposite of how it works. Starvation mode signals to your body to utilize nutrients to the best of its ability and to build muscle if possible. Starvation mode also makes your body burn fat for fuel. There is evidence that many forms of fasting are effective methods for fat loss. Conversely, high-frequency meal consumption has also been shown to impair glucose control and increase hunger.
9. Diet soda is more healthy than regular soda.
Diet soda typically has zero calories, so I guess that's a plus. Otherwise, there is no evidence that diet soda is any healthier or will help you lose weight. Diet drinks are sweetened with artificial sweeteners that are laden with chemicals. Studies show these sweeteners are linked to depression, thyroid disorders, heart disease, and even metabolic syndrome. We now know that artificial sweeteners make people feel hungry, leading you to eat more.
Instead of drinking soda, you could be hitting your daily water goal or drinking a beverage with some health benefits such as green tea or kombucha.
8. Salt is unhealthy.
There are a number of people with salt-sensitive hypertension who should avoid consuming too much sodium. For the rest of us, there is no clear association between salt consumption and high blood pressure. Salt is an essential mineral to a healthy body, but people who are living on packaged foods may be consuming too much. For the people who cook three meals a day and salt their food to taste, you run very little risk of overdoing it.
The real culprit behind hypertension is more likely a diet deficient in salt's partner, potassium. Potassium balances sodium in the body and relaxes blood vessels to lower blood pressure. Unfortunately, most diets today just don't supply enough potassium. Increase your potassium intake by eating more dark leafy greens, avocados, prunes, raisins, squash, and bananas.
7. Whole wheat bread is more healthy than white bread.
White bread and whole wheat bread are not very different, aside from looks and taste. They are very similar in calories and nutrients. Whole wheat bread does have slighly less impact on blood sugar, probably due to the higher fiber content. The difference between the two is negligible.
6. Carbohydrates are the body's main source of energy.
“Conventional wisdom” still preaches the idea that carbohydrates are essential. While it is true that carbohydrates provide very quick energy, they are not the body's primary source of energy. Our bodies are meant to metabolize fat for energy, which is why we have no upper limit on how much fat we can store. Fat is essential. On the other hand, carbohydrates are stored in limited quantity. The liver stores about 100 grams of carbohydrates as glycogen, the muscles store 400-500 grams, and anything beyond that is stored as fat.
This is why carbohydrates are only useful for short term energy, They are metabolized quickly and you'll have to replenish them through food. This leads to a vicious cycle of sugar cravings and builds dependance. It's an inefficient way to release energy, and eating this way long-term will hinder your ability to utilize fat. By switching from a high-carb/low-fat diet to a high-fat/low-carb diet, you can burn fat for energy much more efficiently.
5. Eating fat makes you gain fat.
Ah, the low-fat craze. You just won't die. Fats are a type of lipid. Lipids are essential to life. Your brain structure is at least 60% lipids. The outer membrane of all your cells are made of lipids. Your hormones are made of lipids. Restricting fat in your diet forces your body to metabolize sugar for energy, which means you're not burning fat. You're also likely to feel less motivated to work out on a low-fat diet, because your steroid hormones (especially testosterone) will be low. And, of course, you're much more likely to overeat on a low-fat diet. Fat stimulates two important satiety hormones, PPY and CCK, to make you feel full. Consequently, it's very hard to overeat fat.
A side note, low-fat food “products” are typically very high in sugar to make them taste better. Excess sugar intake will trigger fat storage.
4. Too much protein weakens the bones.
There are many misconceptions about high-protein diets. One of the most common ones is that too much protein in the diet weakens the bones. The idea is that protein increases the pH of the blood and causes calcium to be leached from the bones to “buffer” the acidity. Long term studies refute these claims and actually show that bone-protective hormones are increased with a high protein intake. Protein is essential for staving off bone diseases and providing the building blocks for most body tissues. This is especially important for older populations, since protein absorption declines with age.
3. Too much protein is harmful to the kidneys.
Another common myth is that protein is harmful to the kidneys. First of all, the kidneys are designed to filter metabolic waste from protein metabolism. This is their job. Kidney disease is typically a result of high blood pressure or diabetes, both of which are improved with increasing protein and lowering sugar in the diet. There is substantial evidence that healthy kidneys can handle plenty of protein without damage, so this myth is bunk. Claims such as these lead to people eating dangerously low-protein diets and depriving themselves of essential nutrients.
2. Raw foods contain more nutrients/enzymes.
The idea behind the raw food craze is that “living” food is more nutrient dense than “dead” food. Supposedly, beneficial enzymes contained in raw plants help you to digest the food, but are destroyed in the cooking process. This is false. We don't use enzymes from foods, we use our own digestive enzymes to break food down. If we absorb any enzymes, they are broken down into amino acids. Also, there are many nutrients that are better absorbed after cooking. And, of course, many plants secrete chemicals that are meant to prevent them from being eaten. These plants will require some sort of processing or cooking in order to be edible and do less harm in the gut. Biology does not support that raw food is better.
1. Too much dietary cholesterol leads to heart disease.
Here in the number one spot is the king of all nutrition misinformation. Cholesterol is a very important molecule for health. Cholesterol is a lipid contained in every cell membrane in your body. It's responsible for insulating neurons in the brain, ensuring proper cell division, metabolizing fat-soluble vitamins, producing bile, and it also is essential to the synthesis of hormones and neurotransmitters. Your liver produces up to 2 grams of cholesterol per day! That's a lot. What's more interesting is that your liver will produce less cholesterol if you eat more high-cholesterol foods such as eggs or shrimp. If you're a vegan, your liver will be working overtime to synthesize enough of this valuable nutrient to keep you healthy.
In short, if you eat cholesterol, your body won't make as much, if you eat less, your body makes more. It's production is tightly controlled to ensure that we are healthy.
Even if you do have higher cholesterol levels, there is no reliable medical research showing a clear correlation that low cholesterol levels reduce risk of heart disease. Elevated cholesterol can be a sign that something is amiss. Either you have high levels of inflammation or high levels of oxidation, both of which cause LDL cholesterol to rise. The cool thing is, both LDL and HDL cholesterol are extremely responsive to exercise. LDL cholesterol can be controlled even more by adopting an anti-inflammatory diet that limits alcohol, processed foods, trans-fats, sugar, and grains.
The bottom line is that most of the so-called facts peddled by the media are just nonsense and scare tactics. They will jump all over a misleading study that wants to blame red meat for heart disease, but no one will call out Monsanto for poisoning our food supply. The most valuable nutrition information is common sense. If it wasn't around when your great-grandparents were growing up, don't put it in your mouth. Processed and packaged foods are not health foods. Stick with what nature provided us. Eat vegetables, animals, some fruits, nuts, and you'll do great.