This is probably the most complicated moment in history for making food choices. After all, Paleolithic diners simply roasted mammoth steaks over a fire and served them with a side of nuts and berries. It's not like they had to choose whether to drink low-fat or whole milk, or which of the 200 different kinds of packaged potato chips they'd dive into.
During a trip to most local markets, shoppers are confronted with more than 43,000 items [source: Food Marketing Institute]. Just how, exactly, do we know which foods to choose? For many of us, the decision to reach for fat-free cookies instead of the full-butter version seems like an instinctual one. Fueled by news reports, helpful tips in glossy magazines and the occasional blog, we know to steer clear of fat, high fructose corn syrup, skin-on chicken and more. But what if most of what we read is wrong?
From salt to sugar, we've investigated 10 widely held nutrition "facts" that have little real value and will share the truth with you. We'll start with the dieter's best friend, the low-fat food item.
If you're watching your waistline, chances are you've stocked up on a few helpers: fat-free salad dressing, "lite" mayonnaise and low-fat cookies. Unfortunately, as you munch your way through that box of not-very-tasty fat-free mini-muffins, there are lingering doubts. If so much of what you eat is low-fat or fat-free, why aren't you losing weight?
It's because fat-free foods have a dark side. They may cut out the fat, but it's been replaced with sugar -- lots of sugar, which helps make fat-free foods more palatable. This isn't a better option because sugar is stored in the body as fat [sources: Glassman, Poulter].
Mistakenly believing low-fat foods -- defined as having less than 3 grams of fat per serving -- save calories can also lead to more consumption of the product rather than eating the full-fat version. In fact, some low-fat foods have almost as many (or more) calories and sugar as the regular version. Plus the sodium is often higher. For instance, the Dunkin' Donuts blueberry muffin has 460 calories, 44 grams of sugar and 450 grams of sodium. The reduced fat version has 410 calories, 40 grams of sugar and 620 grams of sodium [sources: WebMD, Dunkin' Donuts].
Some of us don't like potato skins, but we still hear our mothers' voice when we leave it on the plate: "A potato's nutrients are all in the skin." While there's some basis to the statement -- potato skin is rich in fiber and other nutrients -- that's not the whole story [source: Academy of Nutrition and Dietetics].
Truth is, only about 20 percent of the potato's nutrition is found on the skin [source: U.S. Potato Board]. The skin of a medium potato contains 920 milligrams of potassium and 3.6 grams of fiber, while the flesh (without the skin) still offers 676 milligrams of potassium (more than a banana) and 2.6 grams of fiber [source: Flipse]. Not too bad, right?
Plus, the flesh of the potato contains vitamins C, K and B6, as well as a healthy dose of niacin and thiamin. A medium potato's flesh also has magnesium, phosphorus, copper, manganese, zinc, riboflavin and folate -- all for less than 150 calories [source: Self].
As food villains go, high fructose corn syrup (HFCS) is near the top of the list. It debuted in the 1970s and became the darling of the food and beverage industry because it tasted similar to sugar, but was more stable during food processing.
However, as its prominence has grown – HFCS shows up in sodas, bread and condiments, among a vast array of products – so has the size of American waistbands [source: Hendley]. Coincidence or culprit?
The jury is still out. Chemically, HFCS is very similar to sucrose (table sugar). While sugar comprises equal amounts of fructose and glucose, HFCS is 55 percent fructose and 42 percent glucose. An additional 3 percent of larger sugar molecules, known as higher saccharides, make up the rest. Both sucrose and HFCS have the same number of calories. Consuming an excess of either sweetener can lead to weight gain, fatty liver disease, insulin resistance, heart disease and Type 2 diabetes [sources: Parker, Hendley].
However, there does seem to be a difference in the way HFCS (made from corn) and sucrose (made from beets and cane) are metabolized. In studies of rats fed a steady diet of HFCS, the rodents gained a lot more weight and belly fat than the rats that were fed sucrose. Researchers don't yet understand why the HFCS-fed rats were more prone to obesity. One hypothesis is that the excess fructose was metabolized to produce fat, while the glucose was either processed for energy or stored as a carbohydrate in the liver and muscles [source: Parker].
Millions of children have been encouraged to crunch carrots for the sake of their eyesight. But those promises of better vision, including the ability to see in the dark, exist mainly thanks to a wartime propaganda campaign.
During World War II, the British government attributed the ability of its night-flying pilots to shoot down Nazi bombers to their carrot intake. In reality, the pilots were employing a new type of radar. Although it was a ruse to throw Germans off track, the idea caught on. Even British civilians began eating more carrots in order to better find their way around during blackouts, and also planted them in "victory gardens" [source: Smith].
The myth of vision-improving carrots leapt continents and decades, and remains powerful today. While it's true that carrots are good for maintaining vision, they don't offer visual superpowers, like seeing in the dark. However, carrots are high in beta carotene, a component in vitamin A, which is essential for vision. In fact, if a person has a vitamin A deficiency, correcting it can improve poor night vision [source: O'Connor].
Whether it's black, pink, gray or red, sea salt certainly stands out, in flavor, color and texture. The irregularly shaped rocks are gleaned from the sea as water evaporates. The result is a coarse, unprocessed salt laced with trace levels of minerals, such as calcium, magnesium, potassium.
Table salt, on the other hand, is harvested from underground salt deposits and then processed to arrive at its fine and uniform texture. Because all minerals have been stripped away and additives have been included to prevent clumping, this is the less healthful choice, right?
Turns out, sea salt isn't any better for you than table salt, and both should be used in moderation. Sea salt and table salt have the same sodium content, which is about 575 milligrams of sodium per quarter teaspoon (the American Heart Association recommends ingesting no more than 1,500 milligrams a day). Both types of salt put you equally at risk for developing high blood pressure, which in turn raises the incidence of heart disease.
But what about the trace amounts of minerals found in sea salt? They don't really give you a nutritional advantage because they are easily found in other common foods, like nuts, legumes, dairy and some fruits and vegetables, like oranges and leafy greens [source: Kannall].
And the iodine added to table salt to help prevent goiters caused by iodine deficiency? It also is found in everything from fish and dairy products to soy sauce and eggs [sources: American Heart Association, American Thyroid Association].
Fiber is found naturally in many of the foods we eat, like fruits and vegetables, whole grains and legumes. Naturally occurring fiber prevents constipation, lowers the risk of diabetes and heart disease, and even helps maintain our weight [source: Mayo Clinic].
Grocery store shelves are filled with foods that have unexpected additions of fiber, like yogurt, ice cream, sugary cereals and even water. Unfortunately, these fiber-added foods don't offer the same benefits as foods that are naturally high in fiber.
That's because whole foods like oatmeal contain complex fiber, but fiber-enriched foods like white bread rely on a single type of fiber. These isolated fibers are either chemically synthesized or extracted from fiber-rich plants. While isolated fibers do have some benefits, like helping you feel full, there are often too few in a single serving to make much of a difference to your health. In addition, isolated fibers aren't efficient at encouraging bowel movements, and have little impact on blood sugar or cholesterol. Consumed in large amounts, they can cause gas and bloating [source: Berkeley Wellness].
In the end, we're better off eating foods that are naturally fiber-rich because they contain a variety of fibers with clear health benefits. A bagel made with refined flour, that has been fortified with the chemically synthesized fiber, just isn't as good for the body as the whole grain version [source: Berkeley Wellness, Cooking Light].
Behold the skinless chicken breast. A dieter's staple, this bland and dry cut of meat has been appearing atop salads and next to haricot verts for years. Isn't it time to take a closer look at why we're eating it?
If thoughts of roast chicken with crispy, flavorful skin covering a moist and equally savory cut of meat are dancing through your head, pay attention to them. Skin-on chicken isn't as bad as we once thought. A 12-ounce (340-gram) bone-in chicken breast with skin intact will have an additional 50 calories and 2.5 grams of saturated fat more than its boneless, skinless, tasteless counterpart. Plus, 55 percent of the fat in chicken skin is heart-friendly monounsaturated fat [source: Cooking Light]. So feel free to indulge now and again.
In fact, the bone and skin play important roles during the cooking process. The bone will help evenly distribute heat as the chicken cooks, while the skin will keep the exterior from drying out before the interior is fully cooked [source: Royer]. So, you'll get a better flavor if you cook the chicken with the skin on and then remove it before serving.
You've probably heard the Dietary Guidelines for Americans' recommendation to limit saturated fat to less than 10 percent of your daily caloric intake. For many, this has meant cutting back on cheese, ice cream and butter, and switching from whole milk to skim milk (a watery, less flavorful version of whole milk) [source: CDC].
Avoiding fats in dairy was supposed to translate into healthier hearts and slimmer waistlines. The idea that saturated fat increased the risk of cardiovascular disease became popular in the 1950s. (One cup of whole milk has 4.6 grams of saturated fat, 22 percent of the current Recommended Daily Allowance.) However, emerging research finds dairy fat isn't bad for our hearts or our weight. As counterintuitive as it seems, the opposite could be true. Consuming full-fat whole milk has been linked to a reduced risk of cardiovascular disease and Type 2 diabetes, as well as lower blood pressure [sources: Giles-Smith, Teicholz].
Whole milk seems to fight obesity, too. A study published in the "Scandinavian Journal of Primary Health Care" found that if full-fat milk, butter and cream were part of the diets of middle-aged men, they were far less likely to become obese over a 12-year period compared with men who didn't consume high-fat dairy. A meta-analysis of 16 studies, published in the "European Journal of Nutrition," reported the consumption of high-fat dairy was linked to a lower risk of obesity. Similar findings have been reported for children [source: Aubrey].
The benefits lie in whole milk's complex and beneficial fats, which include more than 400 different fatty acids mixed in a healthful milieu of protein, calcium and other nutrients. In addition, scientists suspect whole milk may contain a yet-unnamed substance that alters the metabolism to burn fat for energy, instead of storing it [sources: Giles-Smith, Teicholz].
Know someone eating gluten-free? This diet, intended for those with celiac disease and gluten intolerance, is becomingly increasingly widespread -- even for those who don't necessarily need it. But,
there's little evidence to support the idea that going gluten-free is better for the general population.
People with celiac disease are unable to digest gluten, a protein found in wheat, rye and barley. If they eat gluten, over time it damages the small intestine and makes it difficult to absorb nutrients. Gluten intolerance is marked by fatigue and abdominal distress. Switching to a gluten-free diet can bring a metamorphosis; suddenly, people with celiac disease or gluten intolerance feel better and have more energy. But unless you have the same condition, making the switch won't give you the same results [source: Hendley].
Unfortunately, this is a longstanding food myth. The idea that your body, at an elemental level, is sending signals to your brain forcing you to drink a glass of orange juice or dive into a slice of cheesecake is simply off the mark.
Food cravings, at least for humans, tend to revolve around emotional needs rather than physical ones. In fact, if a food is forbidden (remember that slice of cheesecake?), you'll probably want it all the more. There is one notable exception: If you are nutritionally deficient in iron, you'll have cravings -- but not for iron-rich steak or liver, as you might imagine. Instead, you might chew on significant amounts of ice cubes, a condition known as pagophagia. It's a variant of pica, a disorder in which people eat things -- clay, paper, chalk -- that aren't actually food [source: O'Connor, Weil].
HowStuffWorks takes a look at some fruits that have a lot of sugar, including mangoes and pineapples.
Author's Note: 10 False Nutrition Facts Everyone Knows
I've eaten my share of fat-free cookies washed down with skim milk. And then I decided I'd rather splurge on small amounts of full-fat foods that taste good (where's some umami when you need it?). Good news? This strategy turned out to be just as effective, maybe more so, than trying to replace the foods I liked with low-fat alternatives.
- Academy of Nutrition and Dietetics. "Is Potato Skin the Most Nutritious Part of Potatoes?" (June 14, 2014) http://www.eatright.org/Public/content.aspx?id=6442459089
- American Heart Association. "Sea Salt Vs. Table Salt." May 12, 2014. (June 14, 2014) http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyEating/Sea-Salt-Vs-Table-Salt_UCM_430992_Article.jsp
- American Thyroid Association. "Iodine Deficiency." (June 14, 2014) http://www.thyroid.org/iodine-deficiency/
- Aubrey, Allison. "The Full-Fat Paradox: Whole Milk May Keep Us Lean." NPR. Feb. 12, 2014. (June 18, 2014) http://www.npr.org/blogs/thesalt/2014/02/12/275376259/the-full-fat-paradox-whole-milk-may-keep-us-lean
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- Kannall, Erica. "List of Foods That Are Rich in Magnesium, Potassium and Calcium." Livestrong. Jan. 8, 2014. (June 18, 2014) http://www.livestrong.com/article/70088-list-foods-rich-magnesium-potassium/
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- Mayo Clinic. "Dietary Fiber: Essential for a Healthy Diet." (June 14, 2014) http://www.mayoclinic.org/healthy-living/nutrition-and-healthy-eating/in-depth/fiber/art-20043983
- Parker, Hilary. "A Sweet Problem: Princeton Researchers Find that High-Fructose Corn Syrup Prompts Considerably More Weight Gain." Princeton University. March 22, 2010. (June 14, 2014) http://www.princeton.edu/main/news/archive/S26/91/22K07/
- Poulter, Sean. "Low Fat Foods 'Contain 20 percent More Sugar than Full-Fat Equivalents.'" Daily Mail. April 6, 2014. (June 14, 2014) http://www.dailymail.co.uk/news/article-2598042/Low-fat-foods-contain-20-sugar-fat-equivalents-Experts-warn-lead-weight-gain.html
- Royer, Blake. "Dinner Tonight: Roasted Bone-in Chicken." Serious Eats. March 27, 2012. (June 14, 2014) http://www.seriouseats.com/2012/03/dinner-tonight-roasted-bone-in-chicken-breast.html
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- Smith, K. Annabelle. "A WWII Propaganda Campaign Popularized the Myth that Carrots Help You See in the Dark." Smithsonian. Aug. 13, 2013. (June 14, 2014) http://www.smithsonianmag.com/arts-culture/a-wwii-propaganda-campaign-popularized-the-myth-that-carrots-help-you-see-in-the-dark-28812484/?no-ist
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- U.S. Potato Board. "Are Potatoes Healthy? Yes, They Are." (June 14, 2014) http://www.potatogoodness.com/nutrition/
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- Weil, Andrew. "Pica: Why Crave Ice?" Dr. Weil. July 26, 2010. (June 28, 2014) http://www.drweil.com/drw/u/QAA400757/Pica-Why-Crave-Ice.html