It’s a new year, which means you’re probably reevaluating all your poor health choices and setting a few fitness goals for 2017.
Alas, the internet makes it easier than ever to spread misinformation, often with the best of intentions. Myths that were previously passed through word-of-mouth in gyms and health clubs now spread like wildfire through social media, blogs, forums …
… and even the established media. Between a 24-hour news cycle, studies that are both long and difficult to read, and journalists scrambling for the latest viral hit, information often gets published without being verified.
For decades, fat was the enemy, but today the media has found a new scapegoat: carbs. And generalizing about carbs and insulin seems to get more popular by the year. In fact, in the eyes of many, the glycemic index and the insulin index seem to rank foods by how dangerous they are. Like cholesterol, insulin is misunderstood as being unilaterally harmful.
Yet our bodies need and produce both substances. Cholesterol serves to make pregnenolone, and from there many other hormones, such as testosterone. Insulin is required to store glucose (the sugar in your blood) or use it for energy; it was one of the very first hormones to be discovered, and the first to be investigated in the context of sensitivity.
Early evidence suggested that carbs caused insulin insensitivity. This can be true in diabetics and in insulin-resistant people overeating carbs, but not in healthy people on a healthy diet. This said, there is no denying that modern society makes it very easy to overeat carbs: Processed carbs are often delicious and seldom very filling, despite being high in calories.
Cutting carbs (especially processed carbs) can be a viable fat-loss decision, if it helps you eat less. But if cutting carbs makes you miserable and always hungry, you should consider other options. If you wish to lose weight, what matters is not to replace fat by carbs or carbs by fat, but to end most days on a calorie deficit.
The Truth: Carbohydrates have been vilified long enough. As long as you don’t overindulge, starches are not inherently harmful.
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More: High-carb, high satiety?
Eat fat, gain fat, right? For many decades, the traditional way to lose weight has been to subject oneself to a low-fat diet. But as studies pile on, research plods on, and old wisdoms sometimes must give way. Today, we know that, just like eating cholesterol isn’t likely to increase your cholesterol levels, eating fat isn’t what makes you fat.
Far from being healthy, shunning all fat from your diet can be dangerous, since your body needs to consume at least some omega-3 and omega-6 fatty acids. As for the myth that saturated fat causes cardiovascular disease, it is just that: a myth. At the end of the day, trans fat is the only kind of fat that has been shown to be unilaterally detrimental to health — a little won’t kill you, but avoid it when you can.
The Truth: If you stay in a caloric surplus, a low-fat diet won’t make you lose weight, especially since it can decrease your testosterone production. You need some omega-3 and omega-6 fatty acids, saturated fat won’t give you a heart attack, but too much trans fat may.
Carbs and fats often take the blame for various health issues, but the third macronutrient isn’t always spared by the media. Protein has often been accused of bone and kidney damage.
Let’s tackle those two claims one at a time. An early study reported that protein consumption was linked to increased urinary calcium, which was thought to lead to bone loss over time. Later studies determined that urinary calcium was a poor predictor of bone mass, and that protein actually had a protective effect or no effect on bones.
Another early study determined that high protein diets increased glomerular filtration rate (GFR), a marker for waste filtration in the kidneys. It was argued that increased GFR was a sign that undue stress was put on the kidneys, but later research has shown that kidney damage does not occur as a result of diets high in protein.
The Truth: Protein, even in large amounts, isn’t harmful to your bones. It isn’t harmful to your kidneys either, unless you suffer from a pre-existing condition.
If there’s one thing the media is good at, it’s scaring you away from perfectly innocent foods.
Eggs have been demonized because their yolks, which are chock-full of nutrients, contain high levels of cholesterol. Does that scare you? It shouldn’t, because eating foods high in cholesterol does not translate to increased cholesterol levels in most people.
More to the point, in clinical trials, no association was found between eggs and cardiovascular disease, except maybe in some people with specific pre-existing conditions (such as diabetes or hyperglycemia),
The Truth: Eggs are a great source of proteins, fats, and other nutrients. Their association with high cholesterol and cardiovascular disease has been severely overblown.
More: Are eggs healthy?
… because red meat causes cancer.
Absolute statements like this one are the nutrition myth’s best friend. Cancer is particularly difficult to discuss in absolutes. After all, almost everything we eat has the potential to be involved in cancer development. For example, antioxidants can both promote and hinder cancer growth, but the effect is usually too small to notice.
Some compounds, like polyaromatic hydrocarbons (PAHs), found in smoked meats, have been found to damage the genome, which is the first step to potential cancer. Current evidence suggests that red meat can pose a cancer risk for people with poor diets and lifestyle choices. If you have a consistent exercise schedule, eat your vegetables, and don’t smoke, red meat’s effect on cancer isn’t something to worry about.
The Truth: Fears about cancer and red meat are exaggerated. Making healthy lifestyle choices (such as staying at a healthy weight, exercising, and not smoking) is more important than micromanaging your red meat intake. If you’re going to lay off red meat, start with avoiding too much processed/cured/smoked red meat.
Most myths are rooted in a grain of truth. It’s true that people with salt-sensitive hypertension should avoid too much salt because it raises their blood pressure. In most people, however, there appears to be little to no association between salt consumption and hypertension when controlling for other factors. Instead, evidence suggests an association between high blood pressure and high body weight, as measured by BMI.
Salt (sodium) is an essential mineral; its consumption is critical to our health. The problem is that the average North American consumes double the recommended intake, so quite a bit more than the tolerable upper intake. Excess sodium may not raise blood pressure, but it is associated with other health issues, such as kidney damage and an increased risk of cognitive decline.
The Truth: Salt (sodium) isn’t strongly associated with high blood pressure, except in people with salt-sensitive hypertension. Still, anything in excess is harmful, and sodium is no exception.
Carbs in general have taken a pounding of late, but critics have been especially tough on bread, claiming that any amount of gluten (not a carb, ironically) is a danger to all. However, whereas small amounts of gluten can indeed produce symptoms in people with intestinal disorders, in other people the dose-response relationship for effects hasn’t been well studied.
Furthermore, while gluten gets all the attention, other compounds may be more important for people without celiac disease who suspect they have gluten sensitivity. For example, some of the same researchers who did an initial study on gluten intolerance did a follow-up study and concluded that gluten was not necessarily to blame in those with irritable bowel syndrome. They suggested that compounds falling under the category of FODMAPs (which are present in a variety of plant foods) may be a greater issue.
Nevertheless, gluten research is still in the very early stages, with evidence mounting of non-celiac gluten sensitivity having a reliable biological basis.
The Truth: While some people are sensitive to wheat, the gluten content isn’t necessarily to blame, and other foods may also be implicated.
White bread (made from wheat flour) and whole-wheat bread both contain gluten and related proteins. They provide a similar number of calories, but whole-wheat bread has lower glycemic and insulin indices, and so its consumption results in a lower insulin release. For that reason, and because of its higher fiber and micronutrient content, whole-wheat bread is claimed to be healthier than white bread.
What the media frequently fails to mention is that the actual differences between white bread and whole-wheat bread are relatively small. Yes, whole-wheat bread has a higher fiber content — but this content pales compared to that of many fruits and vegetables. You most definitely don’t have to eat whole-wheat products to get enough fiber in your diet! And yes, white bread does lose more micronutrients during processing — but those micronutrients are often reintroduced later (the bread is then called “enriched”).
If anything, what makes whole-wheat bread markedly different is its higher phytic-acid content. Phytic acid binds to dietary minerals, such as iron and zinc, and can thus slightly reduce their absorption in the body. On the plus side, phytic acid has a protective and anti-inflammatory effect on the colon. So there’s a little bit of bad and a little bit of good.
The Truth: Though whole-wheat bread is claimed to be far healthier than white bread, they aren’t that different, and neither contains high levels of fiber or micronutrients.
Glucose, the sugar in your blood, is your body’s preferred source of energy. Fructose, another sugar, can also be used for energy until the liver is full of glycogen. Once fructose can no longer be used for energy, it is converted into fatty acids.
Early evidence led to the belief that fructose could cause fatty-liver disease, as well as insulin resistance and obesity. By extension, high-fructose corn syrup (HFCS) is frequently said to be unhealthy, since it is high in fructose.
Depending on the production method, liquid HFCS has a fructose content of 42–55%. Sucrose, also known as table sugar, is 50% fructose. The difference (-8% to +5%) is too slight to matter.
The Truth: HFCS and table sugar are very similar from a health perspective. Though HFCS may sometimes contain more fructose, the difference is negligible.
More: Is high fructose corn syrup (HFCS worse than sugar?)
How often have you heard the claim that whole foods are better than supplements? It’s been repeated so often that the word “natural” has a positive connotation whereas “synthetic” or “chemical” has a negative one.
The truth, of course, isn’t so clear-cut. Some compounds are more effective in supplemental form. One example is the curcumin in turmeric, which is often supplemented with piperine (a black pepper extract) or taken in liposomal form to increase its otherwise low bioavailability.
The same goes for vitamins. For instance, phylloquinone (K1) is tightly bound to membranes in plants and so is more bioavailable in supplemental form. Likewise, folic acid (supplemental B9) is more bioavailable than folate (B9 naturally present in foods), though that may not always be a good thing.
Many supplemental vitamins have natural and synthetic forms. This makes them accessible to more people. For example, if B12 could not be synthesized, it would be prohibitively expensive as well as unsuitable to vegans.
The Truth: With regard notably to vitamins, foods are not always superior to supplements.
Unlike its opposite, this myth is seldom voiced out, yet it is often assumed and acted upon. One argument is that intensive agriculture has led to soil depletion, so that natural foods (vegetables and grains and the animals fed on them) fail to provide enough vitamins and minerals. Another argument is that foods are a mess of unknown compounds, in addition to known “poisons” such as the dreaded saturated fat, cholesterol, gluten, and FODMAPs. And to top it all, sticking to a low-carb or low-fat or high-protein diet with only foods is a daily challenge.
No wonder that more than one-third of North Americans take a multivitamin. Better cover one’s bases, or so the thinking goes. Alas, there is no evidence that taking a multi will increase your life expectancy, and while it may support your health in some ways, it could hurt it in others.
Fact is, multis are seldom well conceived. Due to cost and space considerations (people willing to take one pill a day may balk at taking ten), multis are often rich in micronutrients abundant in a healthy diet and poor in others you are more likely to need. You are usually better served by focusing on what you actually need — such as vitamin B12 if you are vegan or a senior, or vitamin D if you seldom see the sun.
In fact, many foods you’ll find at the supermarket are already fortified with the micronutrients you’re most likely to lack. Milk, for instance, is frequently fortified with vitamin D, whereas salt is iodized, and enough foods are fortified with folic acid that you’re as likely to get too much as not enough. In that light, many of our foods also act as supplements; it is therefore tempting to take the next step and live on meal replacements, with all the necessary vitamins and minerals added in and none of the aforementioned “poisons”.
That could work — if we actually knew “all the necessary”. We learn a little more each day, but there’s still much we ignore about food components and their interactions with different systems in our bodies (and with different people). So until we reach a perfect understanding of the human body and its nutritional needs, you’re safer eating a varied diet of little-processed foods than ingesting the same meal replacement day after day after day. And it’ll taste better.
The Truth: Supplements have their use. You can benefit from supplementing specific vitamins or minerals, and a protein powder can make it easier to increase your daily protein intake. But supplements should complete a healthy diet — not replace it.
This statement is not so much a myth as a jumble of misconceptions. First of all, people seldom agree on what “clean” actually means. For some, it means avoiding everything that isn’t natural. For others, it means avoiding all “risky foods” even at the cost of living on meal replacements and other supplements. One common point of clean diets is their negativity: They tell you what clean eating is by telling you what not to eat.
Veganism can be considered the prototypal clean diet, as it shuns all meat products both for ethical reasons and for better health. But although vegans and vegetarians do live longer, this may be influenced by reasons unrelated to food. For instance, people who stick to a vegetarian diet are more likely to also stick to an exercise regimen, practice relaxation exercises (meditation, yoga …), and neither drink in excess nor smoke.
In fact, compared to people eating a varied omnivorous diet, vegans (and, to a lesser extent, vegetarians) are more likely to get less than the optimal amount of some nutrients, such as carnitine or vitamin B12. However, those nutrients can easily be supplemented — nowadays, there are even plant-based options for EPA, DHA, and vitamin D3.
But animal products aren’t the only “unclean” foods for clean-diet proselytizers. You can’t simply “eat your veggies” — you need make sure they’re organic. This is presented as self-evident, on the principle that “natural” is good whereas “synthetic” is bad; yet research has hitherto failed to link organic foods, vegetal or animal, to better health. It doesn’t mean a link cannot exist, but the organic-versus-not debate is complex and can change both with the foods under scrutiny and with the individuals eating them.
One misconception is that no synthetic substance can be used to grow organic crops, whereas the National List of Allowed and Prohibited Substances makes some exceptions. Another misconception is that no pesticide can be used to grow organic crops, whereas natural pesticides exist, are used to grow organic crops, and are not always better for the consumer or the environment.
Pesticide residues in food are a valid concern, though it should be noted that the Pesticide Data Program (PDP) of the United States Department of Agriculture (USDA) has consistently found that the vast majority of the food on the market contained residues below the tolerable limits set by the Environmental Protection Agency (EPA). In addition, rinsing, peeling when possible, and cooking can all reduce the amount of pesticide left on your food.
Is our food clean enough yet? Not quite. Some “clean eating” gurus recommend that you only eat your food raw, so as not to “denature” (see a trend, here?) its nutrients. As an absolute, this rule is bunk. Raw milk can contain harmful bacteria. Raw eggs contain avidin, a protein that can bind certain B-vitamins, such as biotin. Cooking can reduce the nitrate content of vegetables (bad) but also their oxalate content (good). You can’t generalize.
It’s easy to see how one can push the “clean eating” obsession too far, even all the way into orthorexia. It doesn’t mean that all foods are equal, and you certainly should favor whole foods over processed foods — most of which are nutrient-poor, calorie-dense, and easy to overeat — but you shouldn’t fear that eating anything but raw organic veggies is going to drastically shorten your lifespan.
The Truth: “Clean eating” is the new fad, but gurus don’t even agree on which foods are clean and which are not. Stick to the basics. Favor whole foods (but don’t feel like any amount of processed foods will kill you), eat organic if you want and can afford it, peal or wash your vegetables and fruits (especially those with higher levels of pesticide residue, such as strawberries), and avoid stressing too much about what you eat, since stress can shorten your lifespan.
“Detox diets” are the ultimate manifestation of the “clean eating” obsession. Such diets commonly limit foods to plant-based juices, sometimes seasoned with a supplement. After a few days of that regimen, you’re supposed to be cleansed of …
Of what? Good question. A 2009 investigation of ten companies found they couldn’t name the “toxins” targeted by any of their fifteen products — let alone prove those products’ efficacy. Strictly speaking, toxins are plant- or animal-based substances poisonous to humans; but for many detox gurus, “toxins” also include heavy metals … and everything synthetic: not just toxicants (man-made poisons, such as pollutants or pesticides), but also preservatives, high-fructose corn syrup, etc.
Alas, even when a substance really is noxious, a “detox diet” won’t help. Acute toxicity would likely constitute a medical emergency, whereas chronic toxicity is best addressed by a well-fed body — not one weakened by a severely hypocaloric diet. The liver, kidneys, lungs, and other organs toil around the clock to remove harmful substances and excrete the waste products of metabolism; don’t hinder their work!
But if “detox diets” are more likely to harm than help, what explains their current popularity? One answer is: quick weight loss. Deprive your body from carbohydrate and you can exhaust its glycogen stores in as little as 24 hours. The resulting loss of several pounds can convince you the diet had a positive effect. When the diet ends and you resume your regular eating habits, however, the glycogen and associated water come rushing back in, and with them the pounds you had shed.
The Truth: Focus on sustainable health habits, such as eating nutritious food on a daily basis. Ample protein, leafy greens, and foods chock-full of vitamins and minerals are not just tastier than anything a “detox diet” has to offer, they’re also way better for you (and your liver detoxification pathways, ironically).
It’s easy to trace this myth back to its origin. Digestion does raise your metabolism a little, so eating less food more often should keep your metabolism elevated. In theory. In practice, evidence shows that, given an equal amount of daily calories, the number of meals largely makes no difference in fat loss. Moreover, some studies suggest that having smaller meals more often makes it harder to feel full, potentially leading to increased food intake.
The Truth: Digestion does slightly increase your metabolic rate, but meal frequency has less effect than the total caloric content of the food consumed.
Some studies show a fat-loss advantage in early eaters, others in late eaters. Overall, early eaters seem to have a slight advantage — nothing impressive.
Trials, however, imperfectly reflect real life. In real life, there are two main reasons why eating at night might hinder fat loss, and both are linked to an increase in our daily caloric intake. The first reason is the simplest: If, instead of going directly to bed, we first indulge in a snack, then the calories from that snack are calories we might have done without. The second reason is that, when we get tired, we tend to eat to keep going — with a predilection for snack foods or sugary treats. So if we stay awake at night, especially to work or study but even just to watch TV, we’re more likely to eat, not out of hunger, but to help fight sleepiness.
The Truth: Eating late won’t make you fat, unless it drives you to eat more.
Let’s get one thing out of the way. If you exercise near maximal capacity (sprints, HIIT, heavy lifting …), eat first, or you’re more likely to underperform. Most people who choose to work out in a fasted state, however, opt for some form of “cardio” (aerobic exercise), such as jogging.
During cardio, performance and energy expenditure while fasted are about the same as in a fed state. In a fasted state, you’ll burn more body fat, but that won’t make it easier for you to use body fat as fuel during the rest of the day (when you’re fed). You’ll also burn a tiny bit more muscle, but you’ll grow it back faster afterward, too, so that it seems to balance out (as long as you get enough protein). Finally, cardio suppresses appetite less on a fasted state than on a fed state, but that doesn’t translate into a significant difference in daily caloric intake.
The Truth: There’s very little difference between cardio on a fed or fasted state with regard to fat loss, muscle preservation, daily caloric intake, or metabolic rate. What really matters, then, is you. Some people feel lighter and energized when they do cardio on an empty stomach, while others feel light-headed and sluggish.
When you exercise, you damage your muscles, which then need to be repaired (and possibly made more resilient, thus bigger). The raw material for this repair is the protein you ingest, yet the existence of a post-workout “anabolic window” for this ingestion remains a contentious topic in the literature.
“You need protein right after your workout” may not be a myth so much as an exaggeration. Consuming 20–40 g of protein within the two hours following your workout may be ideal, but it isn’t necessary. What matters most is your daily protein intake. To maximize muscle repairs, aim for 1.5–2.2 g of protein per kilogram of bodyweight per day (0.68–1.00 g/lb/day).
The Truth: You don’t need protein immediately after your workout, but you might benefit from 20–40 g within the next couple of hours (and before bed). What matters most, however, is how much protein you get over the course of the day.
You’ve likely heard all 17 of these myths repeated at one time or another somewhere in the media. Misinformation is pervasive, which makes identifying it very difficult.
And really, this is just the tip of the iceberg. You can just look at the way the media handles the latest studies — for instance the recent low-carb vs. low-fat study. You need a team of experts to really look into the evidence and figure out what has practical relevance.
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Mark has helped thousands of clients and readers make lifestyle changes that lead to better long-term health, which includes acceptable body fat and ideal body weight.He does not recommend fad diets, quick weight loss gimmicks, starvation diets, weight loss pills, fat burner supplements and the like.