17 Silliest Diet Myths and What Science Really Says

17 Silliest Diet Myths and What Science Really Says

“If you repeat a lie often enough, it becomes the truth.”

It’s frightening how true this statement is given that it comes from Joseph Goebbels – Adolf Hitler’s master of propaganda.

Nowhere is it more prescient than in the world of weight loss. If you’ve tried in vain to drop the excess weight, I can almost guarantee you’ve encountered lies about dieting—lies that have been repeated so often on TV, in print, on the radio and across the internet that they are now accepted as truth.

It’s time to debunk these myths. Today, we’ll look at what the science really says, and reveal the truth about 17 of the most ridiculous myths making the rounds in popular media today.

MYTH #1: Regular detoxes will help clear your body of harmful toxins and keep you healthy.


Food and water you ingest, as well as the air you breathe, are packed with toxic chemicals that can harm your body, or so the myth goes. Thus, in order to rid your organs of these toxins, some diet gurus recommend regularly setting a few days aside where you avoid eating solids altogether and drink juices made of turnip, celery, and kale, among other ingredients. The ingredients in these liquids are supposed to cleanse your body and allow you to purge them all out. Another method of detoxifying would be to flush your colon with lots of water, coffee, or even bentonite to get rid of impurities.

What science actually says:

Although you do end up ingesting some toxins and impurities along with your food, water, and air, your body already has its own detoxifying system, which consists mainly of your liver, spleen, and kidneys.

Drinking juice has not been proven in any way to help them perform their functions better. Moreover, depriving your body of solid foods also severely limits the liver’s supply of amino acids, which are essential to the detoxification process. These amino acids are responsible for making the toxins in your body more soluble in water, consequently making them easier to eliminate with bile.

MYTH #2: Full-fat dairy products can cause obesity and trigger heart disease.

It has long been argued that whole milk is unhealthy because it contains a lot of fat, which supposedly raises cholesterol levels significantly and causes arteries to harden.

A lot of people remove dairy from their diets when trying to lose weight. This, however, could be counter-productive.

What science actually says:
Cutting dairy products actually sends our body signals to produce more fat. This is according to Micahel Zemel, PhD, director of the Nutrition Institute at the University of Tennessee at Knoxville.

“When your body is deprived of calcium, it begins conserving calcium. That mechanism prompts your body to produce higher levels of a hormone called calcitriol, and that triggers an increased production of fat cells,” explains Dr. Zemel.

Aside from containing a minimal amount of saturated fatty acid, whole milk also contains oleic acid. This fatty acid is the same component found in olive oil, which is actually very good for the heart. In fact, full-fat milk taken from grass-fed cows has been known to cause up to a 69 percent decrease in the occurrence of heart disease.

MYTH # 3: Fructose is an unhealthy substitute for sugar.

Fructose has a possibility of damaging the liver when too much of it is stored as fat and many have sworn off the product.

What science actually says:

Fructose is actually the “free sugar” found in fruit and agave syrup or it is bonded to glucose to form sucrose, which is actually the table sugar we normally consume in food. Fructose blends like high-fructose corn syrup (HFCS) and honey and are actually not that much different from regular sugar. While HFCS typically used in food production has a 55:45 fructose-to-glucose ratio, table sugar’s ratio is a very similar (50:50). This translates to roughly just five more grams of fructose for every 100 grams of HFCS, as compared to an equal amount of regular table sugar. Both kinds of sugar also produce almost the same effects on the body’s insulin, glucose, and triglyceride levels. However, research is mixed on this issue.

The problem with high fructose corn syrup, however, is that it’s everywhere. And it’s so easy to consume too much of it without being aware of the fact.

Julie Haugen, MS, RDN
Julie Haugen, MS, RDN

Our nutritionist, Julie Haugen, has this to say about fructose:

Fructose is 1.73 times sweeter than sucrose and that sweet taste may trigger the brain to want to consume more than we can metabolize. Excessive fructose consumption may contribute to the development of non-alcoholic fatty liver disease and weight gain and increase the effects of the aging process when consumed with protein due to glycation. Some people are not able to absorb fructose due to malabsorption issues, particularly those who suffer from irritable bowel syndrome. If you don’t have a fructose malabsorption issue, it is best to consume foods with fructose in moderation.

MYTH #4: All fats cause weight gain and increase the risk of heart attack.

Not all fats are bad fats. While trans fats contained in cookies, chips, and greasy foods do increase your cholesterol levels and make you more susceptible to certain diseases, fats in nuts, fish, and avocados are actually healthy and help protect your heart, as well as rebuild your cells and aid in hormone production. Always keep in mind that your body gets essential nutrients from three food groups: proteins, carbohydrates, and fat. Limiting your fat intake will deprive your body of the nutrients it needs to function well.

Additionally, saturated fats and dietary cholesterol have often been thought to increase blood cholesterol and cause heart disease. However more recent research reviews have found these fats may actually increase your body’s HDL “good” cholesterol, while at the same time making LDL “bad” cholesterol less harmful. Thus, a reasonable amount of saturated fats and cholesterol in the diet is actually quite healthy.

It’s important to note though that 25% of the population are referred to as “hyper-responders”. In this group, dietary cholesterol does modestly increase both LDL (“bad cholesterol” and HDL (“good cholesterol”), but it does not affect the ratio of LDL to HDL or increase the risk of heart disease.

MYTH #5: Drastically cutting down on calories will lead to easier weight loss.

Some diets advocate cutting down on calories drastically to promote rapid weight loss. However, consuming too few calories actually slows your metabolism down, making it more difficult to burn fats away.

What science actually says:

When you feed your body with too few calories, it responds by restricting calorie expenditure. The body enters what most people call “starvation mode”. This is well-documented and scientists call it “adaptive thermogenesis”. This was useful when food was scarce. Today, the problem is actually too much food.

It’s better to consume nutrient-dense quality calories instead of empty calories. This is important because different types of calories from different food items pass through different metabolic pathways in your body, causing them to have various effects on nutrient absorption.

MYTH #6: All carbohydrates cause weight gain and increase your risk of heart disease.

Sure we want to avoid unhealthy, refined carbohydrates, such as white bread and white rice. . These foods are more quickly converted into sugar in the body than complex carbohydrates.

What science actually says:

Complex carbs from whole grains, vegetables and fruits, and legumes can actually help improve your health because they contain lots of fiber and nutrients. Carbohydrates are the body’s main source of energy and cutting down on too many carbohydrates will only make your body weaker. Low-carb diets usually recommend only 20 grams daily, which is very far from the recommended daily allowance of 130 grams. A deficit in carbohydrates can cause fatigue, irritability, and constipation, as well as colon cancer or heart disease in the long run. We suggest if you want to follow a low carb diet, do so under the guidance of a nutritionist/dietitian to help you properly gauge what you can do to curb side effects.

MYTH #7: Too much protein strains your kidneys and causes osteoporosis.


Beef steak on wooden table

Although patients with kidney disease are advised to cut back on their protein consumption, healthy people should by no means limit the amount of protein-rich food they eat. In fact, protein helps lower blood pressure and combat type 2 diabetes , which are both risk factors for kidney failure.

In addition, although protein can stimulate the excretion of calcium from the bones in the short term, this is not something to be concerned about in the long run. In fact, protein-rich diets have often been found to lead to a reduced risk of fractures and incidence of osteoporosis , especially in old age.

MYTH #8: Gluten-free diets can help decrease weight and increase energy levels.


Gluten in itself does not cause weight gain. However, because it is found in many fattening refined food items such as grains and white flour, it has often been pinpointed as the culprit behind increasing waistlines.

Furthermore, gluten-free diets are really only intended for patients who are either gluten intolerant or have celiac disease. Gluten intolerance causes abdominal pain and fatigue upon consumption of gluten, while celiac disease causes nutrient deficiencies because the body’s inability to digest gluten leads to damage in the small intestines.

Thus, while steering clear of gluten can cause relief and increase the energy of patients suffering from these conditions, healthy people will receive no such benefits.

MYTH #9: Eating small, frequent meals can speed up your metabolism.

The only thing frequent eating can do is to keep away hunger pangs. Otherwise, some experts believe that it does almost nothing for the body. Depending on the types of foods you eat, eating frequently can lead to the consumption of too many calories, which is counterproductive to weight loss goals. Your metabolism speeds up only very slightly whenever you eat something new, and you end up burning only a fraction of a calorie more than normal. Some studies even suggest that eating too frequently can increase abdominal and liver fat.

MYTH #10: Egg yolks contain lots of fat and cholesterol.

Egg yolks have a bad reputation of being bad for the heart. However, not only do egg yolks contain good, heart-healthy cholesterol, but they are also dense in a lot of other nutrients: vitamins A, E, D, and K, fatty acids, and choline. Eating only egg whites leaves you with only protein, which is a tremendous waste of the health benefits you can get from the yolk. Besides, your body already compensates for the minimal amount of cholesterol in eggs by producing less natural cholesterol.

MYTH #11: Raw foods aid in digestion and burn more calories.

This myth states that skipping the cooking process preserves vital enzymes that can aid in your digestion, as well as add to the limited supply of natural enzymes in your body. However, this claim is not founded in science.

The supposedly vital enzymes that are saved from cooking are made for plant survival and are relatively useless for human health. Cooking vegetables can neutralize enzymes that would cause digestive problems and remove anti-nutrients, which can interfere with the assimilation of vitamins and minerals.

Additionally, the healthy human body is very efficient in producing as much digestive enzymes as it needs to function properly and does not need enzymes from additional sources. However this is not true for everyone, often as we age we can benefit our digestion by taking digestive enzymes because our bodies produce less as part of our aging process. It is actually good to eat a blend of raw and cooked veggies so you are getting an array of nutrients to promote better health. Not all veggies should be eaten raw, such as cruciferious veggies, potatoes, sweet potatoes, beans and mushrooms.

MYTH #12: Fat- and sugar-free foods are always the better option.

Fat-free is not always equivalent to healthy. In fact, most food items that are low in fat contain lots of calories, sodium, and sugar in order to compensate for lack of flavor. Unfortunately, these added ingredients actually add more to your weight than you will save from consuming something that has no fat.

The same holds true for sugar-free food, especially for sodas and other beverages loaded with artificial sweeteners to make up for the lack in flavor. Experts recommend that a third of your total calorie consumption should come from fats. Your body needs fat in order to create energy for tissue repair, as well as for the transfer of vitamins and minerals throughout your body.

MYTH #13: Red meat causes all sorts of diseases.

Reports have been surfacing about how beef can increase your risk of contracting type 2 diabetes, heart disease, and even cancer, among other diseases. However, these studies made no distinction between processed and unprocessed meats.

Further research has suggested that there is little to no link between eating unprocessed red meat and contracting any of the aforementioned diseases. Besides, it is not so much the meat itself that causes the increased risk of disease, but the food you eat with it: processed cheese, bacon with nitrates, onion rings, and other greasy foods.

Beef itself is a rich protein source that also has high levels of iron and the grass-fed variety even contains lots of vitamin E and omega-3 that can help keep your heart healthy. Just make sure to buy the unprocessed kind, and don’t overcook it to avoid eating harmful burnt meat.

MYTH #14: Microwaving food removes nutrients from your food and adds dangerous compounds.

The cooking method you use does not in any way affect the nutrient content of your food. It is really the level of heat and amount of cooking time that removes nutrients – more heat and time causes the loss of water and heat-sensitive nutrients like thiamine and vitamin C. In fact, cooking with a microwave actually helps keep your food’s nutrient content because it uses less heat and time.

Moreover, the radiation that comes from your microwave is much weaker than harmful X- and gamma rays, so it does not add dangerous compounds to your food. Besides, the cooking process actually generates heat from inside your food and not the actual microwave, so you have nothing to worry about. Just make sure to use microwave-safe containers to avoid leaching compounds from plastics into your food.

MYTH #15: Coffee is unhealthy.


Coffee is often given a bad reputation because of all the caffeine it contains. Nonetheless, this beverage actually has many health benefits that far outweigh the negative effects of caffeine (researchers are finding out that some caffeine isn’t all that bad either), as long as it is consumed in moderation.

For one, coffee contains large amounts of antioxidant phytochemicals, even more than those contained in both fruits and vegetables.

Coffee has also been found to play a part in lowering the risks of depression, gall stones, type 2 diabetes, Parkinson’s disease, Alzheimer’s disease, and even some kinds of cancer. Research has even suggested that coffee drinkers have a higher chance of living longer than non-coffee drinkers.

WARNING: Just make sure to drink in moderation and to keep your calories in check and to stay away from too much sugar, cream, and flavored syrups.

MYTH #16: The only thing bad about sugar is that it contains empty calories.

sugar addiction

You’re probably getting tired of reading about it. But it’s really worth repeating.

Sugar has been known to be harmful to the body when consumed in excess amounts. However, the common belief is that it is only the empty calories in sugar that make it unhealthy. But sugar can do much more damage than that. When ingested in very large amounts, sugar has the power to cause very severe problems in metabolism. Studies also show that sugar may play a part in increasing the risk for several diseases, such as obesity, diabetes, heart disease, and even some cancers. Nonetheless, sugar consumed in minimal amounts should not cause any problems, especially for those who have healthy metabolisms and are physically active.

MYTH #17: Eating late at night makes it easier to gain weight.

It is believed that your body stores more fat when you eat late at night because it is not burned off through physical activity. However, it’s not actually when you eat that matters, but the total amount of food you consume within 24 hours. Nonetheless, eating regular meals can help you regulate your appetite so you don’t end up eating too much high-calorie food when you get hungry.

Keep in mind that eating a larger portion of food too close to bedtime can lead to digestive complaints or sleep difficulties, so best to keep your portion sizes small on any food items you eat close to bedtime!


[1] The 10 Dumbest Diet Myths, t-nation.com, Published December 8, 2014, Retrieved June 12, 2015.

[2] You can’t detox your body. It’s a myth. So how do you get healthy?, Dara Mohammadi, The Guardian, Published December 5, 2014, Retrieved June 12, 2015.

[3] The Full-Fat Paradox: Whole Milk May Keep Us Lean, Allison Aubrey, The Salt, Published February 12, 2014, Retrieved June 16, 2015.

[4] Bovine milk in human nutrition – a review, Anna Haug, Arne T Høstmark, and Odd M Harstad, Lipids in Health and Disease, Published September 25, 2007, Retrieved June 16, 2015.

[5] Sugar Isn’t Any Healthier Than High Fructose Corn Syrup, Beth Skwarecki, Life Hacker, Published February 26, 2015, Retrieved June 16, 2015.

[6] Fructose, Wikipedia, Retrieved July 2, 2015.

[7] Is “Starvation Mode” Real or Imaginary? A Critical Look, Kris Gunnars, Authority Nutrition, Retrieved July 2, 2015.

[8] Is your food nutrient-dense or just empty calories?, B’Onko Sadler, Michigan State University Extension, Published August 12, 2014, Retrieved June 18, 2015.

[9] Negative Side Effects of Low-Card Diet, Adam Cloe, Livestrong.com, Published May 06, 2015, Retrieved July 2, 2015.

[10] The Protein Myth – Is Too Much Protein Bad for Your Bones?, Kris Gunnars, Authority Nutrition, Retrieved June 18, 2015.

[11] Study finds high protein diets lead to lower blood pressure, EurekAlert!, Retrieved June 18, 2015.

[12] Protein in optimal health: heart disease and type 2 diabetes, Donald K Layman, Peter Clifton, Mary C Gannon, Ronald M Krauss, and Frank Q Nuttall, The American Journal of Clinical Nutrition, Published May 2008, Retrieved June 18, 2015.

[13] Helping Fractures Heal (Orthobiologics), OrthoInfo, Last Viewed January 2010, Retrieved June 18, 2015.

[14] Going gluten-free just because? Here’s what you need to know, Holly Strawbridge, Harvard Health, Published February 20, 2013, Retrieved June 19, 2015.

[15] 6 Meals a Day for Weight Loss, Amy Paturel, WebMD, Retrieved June 19, 2015.

[16] Eggs and Heart Disease, Harvard T.H. Chan of Public Health Nutrition Source, Retrieved June 19, 2015.

[17] Vegetables You Shouldn’t Eat Raw, Serena Styles, SF Gate, Retrieved July 2, 2015.

[18]Fact or Fiction: Raw veggies are healthier than cooked ones, Sushma Subramanian, Scientific American, Published March 31, 2009, Retrieved June 19, 2015.

[19] Think Raw Veggies are the Best? Think Again, The Healthy Home Economist, Retrieved July 2, 2015.

[20] Low-Fat Diet: Why Fat-Free Isn’t Trouble-Free, Kathleen M. Zelman, RD, LD, WebMD, Published October 02, 2014, Retrieved June 19, 2015.

[21] Artificial sweeteners: sugar-free, but at what cost?, Holly Strawbridge, Harvard Health, Published July 16, 2012, Retrieved June 19, 2015.

[22] The Truth About Red Meat, Elizabeth Lee, WebMD, Published August 29, 2011, Retrieved June 19, 2015.

[23] Microwave cooking and nutrition, Harvard Health, Retrieved June 19, 2015.

[24] The Buzz on Coffee, Kathleen M. Zelman, MPH, RD, LD, WebMD, Retrieved June 19, 2015.

[25]Mounting Evidence Suggests Coffee May Actually Have Therapeutic Health Benefits, Joseph Mercola, Mercola.com, Published September 16, 2012, Retrieved June 19, 2015.

[26]10 Disturbing Reasons Why Sugar is Bad For You, Kris Gunnars, Authority Nutrition, Retrieved June 19, 2015.

[27]Diet Truth or Myth: Eating at Night Causes Weight Gain, Kathleen M. Zelman, WebMD, Published September 08, 2011, Retrieved June 19, 2015.

Related Posts