What is Clean Eating? (Evidence Debunks the Concept of Unhealthy Foods)

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Clean Eating appears on the internet a whopping 9.6 million times. 

It's no wonder it's such a pervasive idea in gyms, online, on your televisions and even in the Doctor's office. 

You’ve heard it a thousand times before. The foods you eat are ‘destroying' your health because they're unclean. You’re not going to reach your fitness goals unless you’re eating clean. You’re not healthy unless you’re eating clean. You’re getting fat because your food choices aren't clean. 

In more ways than one, clean eating has become the new religion. Major fitness publications and otherwise reputable magazines regularly post articles like “the ultimate clean eating grocery list” and “the beginners guide to clean eating”. There’s only one problem with this; what exactly is clean eating?! Allow me to jump the gun a bit here and clarify (warning: spoiler alert):

Clean Eating Doesn't Exist. Click To Tweet

Don’t agree with me? Ok, let’s look at the evidence that backs up that claim. First of all, let's clarify the definition of clean eating. Does clean eating mean only eating lean protein and leafy greens? Does it mean eliminating carbs? Does it mean staying away from gluten? Does is mean no fast food? Does it mean staying away from processed foods? Eating whole grains instead of processed grains? Eliminating added sugar from your diet?

The problem with the notion of clean eating is that its definition depends largely on who you ask, and not on empirical evidence. 

The problem with the notion of clean eating is that its definition depends largely on who you ask, and not on empirical evidence. 

  • Paleo proponents will tell you that anything that has been altered afters it’s been killed or pulled from the ground is unhealthy. 
  • Low-carb proponents will tell you that sugar and refined carbs are bad for you. 
  • Vegans tell you that animal products are bad for you. 
  • Organic loving, granola munching, mason jar-carrying hipsters will tell you processed and packaged goods are bad for you and mother earth. 

You pick a food and I’ll bet I’ll be able to find someone who thinks it’s bad for your health and therefore doesn't fit the definition of clean eating. 

Empirical evidence suggests that, in reality, no objective definition of clean eating exists. Intuitively, this makes sense. Since there’s no way to adequately define clean eating, there’s no way to measure it. Without a way to quantify a diet, there’s no way you can label it as “cleaner” than another.

The False Dichotomy of Clean Eating

At the end of the day, the idea of clean eating suggests that some foods are “bad” for you and some foods are “good” for you. This dichotomy is ultimately incorrect for a number of reasons. To find out why, let’s first present the different ways that a particular food is theoretically able to contribute to your diet and health in a negative way:

     1. Directly interfering with your body’s functions, causing fat gain, aging and specific diseases. 

     2. Taking up such a large degree of your diet so as to dilute it and cause nutrient deficiencies. (1)

     3. Contributing to a caloric excess which causes fat gain and health problems. (2)

We’ll look at each of these one by one. 

Food directly damaging your health

There is absolutely no evidence whatsoever that any one type of food can harm your health independent of its effect on the nutrient density or caloric content of your diet. Any and all foods can be bad for you in too high a quantity, indeed, even water can kill you if you consume too much of it.

When people say that a particular food is “bad”, they’re ignoring a very simple, fundamental point about food. That is, it’s all composed of the same things.

Ultimately, all food is composed of at least 1 of the 3 macronutrients (protein, carbohydrates, and fats), along with various micronutrients. Using carbohydrates as an example, the carbohydrates found in ice cream, pizza and donuts are exactly the same as the carbohydrates found in yams, broccoli and every other vegetable in existence. (3) Your body can’t tell the difference between any of the carbohydrates in these various sources. Regardless the source of the carbohydrate, it’s all turned into the same thing by your body in the end – glucose. (4)

The same thing can be said about protein and fats. No matter the physical food source, they’re ultimately seen and used in the exact same manner by your body. 

Whether people realize it or not, when they state that a particular food is damaging or “bad” for your health, they’re insinuating that it has some element unbeknownst to science that is somehow able to supersede the laws of physics and biochemistry and negatively effect your health in a unique way.

Whether people realize it or not, when they state that a particular food is damaging or “bad” for your health, they’re insinuating that it has some element unbeknownst to science that is somehow able to supersede the laws of physics and biochemistry and negatively effect your health in a unique way.

 Examples of these kinds of claims are the following:

     1. Sugar is will cause your insulin to spike a crash and make you fatter.

     2. Grains are bad for you and should be avoided at all cost. 

     3. Fructose is bad for your liver and will make you fatter. 

     4. Saturated fats are bad for you, so stay away from red meats.

     5. Gluten is bad for you and is responsible for a whole host of health problems

     6. Processed foods are bad for you because they’re not natural. 

     7. Cholesterol will clog your heart and cause disease. 

I’ll examine each of these claims below, but first it must be noted that all of these claims are either false or out of context. Remember, anything can be bad for you in high enough of a quantity. What we really need to know is if any of these foods are damaging to your health as part of a normal diet when consumed in normal amounts. I’ll examine this by responding to each one of the above claims below. 

1. There is no evidence that any particular food will accelerate fat loss at the same caloric level beyond any other, sugar included. In fact, studies show that you could eat nearly half of your total daily calories from sugar and lose just as much fat as someone who only gets 4% of their calories from sugar. (5)

Consuming a moderate amount of sugar does not decrease insulin sensitivity or hurt your ability to process glucose in any way, so-long if you’re not over eating. (6) If you’re overeating, then you have bigger fish to fry than just your sugar intake. For further reading on the issue of sugar and carbohydrates and your diet, read this excellent article

2. There is no evidence that grains damage your health. In fact, there is empirical research that suggests the contrary. (7)

There is no evidence that grains damage your health. Click To Tweet

3. Fructose will not contribute to obesity or cause liver damage unless consumed in massive amounts and as part of an overall caloric excess. (8) There’s no evidence that it’s harmful in normally eaten amounts or that it contributes to over eating compared to normal sucrose. (9)

4. I have an article dedicated to saturated fat here (link will open in a new window). To summarize it, there is little evidence that a diet that is moderate in saturated fat is unhealthy. Past research has come under a considerably amount of scrutiny for it’s limitations and newer research has exonerated saturated fat by showing weak or nonexistent correlations between heart disease and saturated fat intake. (10)

5. I’ve written extensively on Gluten here (opens in a new window). Gluten is not unhealthy or harmful to anyone without celiac disease. Gluten sensitivity probably doesn’t exist outside of the celiac population. (11) Gluten-free products are perhaps the best example of overblown sensationalism from non-scientific sources in the nutrition industry today.

… any food ever labelled as “bad” or harmful” to your health is perfectly fine for you in moderation as part of a normal diet.

 6. There’s a significant problem in this as there’s no clear definition of what constitutes a processed food item. It means different things to different people. However, to generalize, we can say that it is any alteration from a foods natural state. There are no studies that illustrate that a processed food item is in any way worse for you than a non-processed food item. In fact, there are many studies done on processed food items that show dramatic benefits of processed food items. (12) A perfect example is whey protein. 

7. Despite widespread acceptance amongst health professionals, there is growing evidence that cholesterol is not indicated in atherosclerosis and heart disease. (13) Irrespective of that fact, foods that contain saturated fat, when eaten in moderation in the context of a normal diet, show little to no correlation with heart disease and health problems. 

Now obviously this list is not comprehensive. Looking at every different element of the diet is perhaps nearly impossible to do within the context of an article like this. However, it can be said that no food has been scientifically proven to contribute to obesity more than any other, outside of its ability to contribute to a caloric excess. It can also be said that any food ever labelled as “bad” or harmful” to your health is perfectly fine for you in moderation as part of a normal diet. I’ve yet to see any claim to the contrary supported by empirical data. 

The only case where this conclusion is incorrect is if you have a preexisting medical condition. In that case, your body isn’t performing in a normal manner and it is unable to properly handle certain foods. Some examples of these cases are listed below:

  • Those diagnosed with celiac disease should not consume gluten.
  • Those with a peanut allergy should not consume food products that contain peanuts.
  • Those with insulin resistance would benefit from a lower carbohydrate-based diet. (14)
  • Those diagnosed with lactose intolerance should stay away from dairy. 

Again, this list is not exhaustive, but it’s there to emphasize the point that certain medical diagnoses necessitate avoiding certain food groups from a health and safety standpoint. In contrast, evidence tells us that healthy individuals needn’t unnecessarily do the same.

Food Creating Nutrient Deficiencies

Another popular idea that gets thrown around is that foods can be inadvertently bad for you by creating a nutrient deficiency in your diet. That is, by eating foods that are relatively high in calories and low in micronutrients (sometimes referred to as ‘empty calories’), you make it impossible to consume enough micronutrients through the remainder of your diet without going into a calorie excess for the day and subsequently gaining weight. 

Here again, we run into the problem of what “nutritious” means. There are no universally agreed upon standards for what constitutes a nutritional deficiency. Governments often heavily favor the intake of grains and suggest a smaller intake of saturated fats, despite considerable evidence against these recommendations.

Other health and fitness companies have tried unsuccessfully to somewhat arbitrarily assign foods using a point system. (15) Others think antioxidants should be the measure for which we rank nutritiousness, despite there being little evidence that a food’s antioxidant levels indicate its overall healthiness. (16)

It’s clear that trying to label individual foods as good or bad or healthy or unhealthy is pointless. Doing so would illustrate a lack of adequate knowledge of basic physical and biochemical processes and needlessly vilifies foods which would otherwise be perfectly reasonable to consume. 

Regardless of the futility of trying to decide which foods are healthier, it is true that some foods simply contain more nutrients than others. Ice cream does not have the same nutrient content as an orange. However, that doesn’t mean that ice cream constitutes “empty calories” – as many would proclaim. Even ice cream contains dairy, which has many proven health benefits. (17) Sure, it might not have as many micronutrients as an orange, but that doesn’t mean you mustn’t have any. 

Unless you are eating a great deal of pure sugar everyday, it’s unlikely that anything you’re going to eat in moderation will cause a nutrient deficiency.

 There is plenty of room for less nutrient-dense food in your diet on a daily basis. Indeed, the CDC estimates that approximately 90% of American are consuming adequate micronutrients, despite the fact that a large number of these Americans are consuming what would traditionally be considered an “unhealthy” diet. (18) Studies show that an individual would have to eat about 20% of their total daily calories from pure refined sugar before it became impossible to meet their suggested daily intake of micronutrients while remaining in a calorie deficit. (19) Unless you are eating a great deal of pure sugar everyday, it’s unlikely that anything you’re going to eat in moderation will cause a nutrient deficiency. 

Ironically, studies show that people who strictly avoid certain foods or food groups altogether are the ones who are often nutrient deficient. (20) Who would avoid certain foods or food groups? Bodybuilders, fitness fanatics, health conscious individuals who believe something is bad for them. In an attempt to be more healthy, people often end up achieving the opposite. This demographic is also the most likely to be dieting, which incidentally is a risk factor for being micronutrient deficient. Combining restrictive dieting and omitting entire food groups is a recipe for disaster that are often near impossible to maintain, and as discussed, totally unnecessary. 

Short of going to the 5cent candy aisle of your nearest convenience store every day and drowning yourself in sugary sweets while still attempting to maintain a caloric deficit, it’s safe to say that you probably don’t need to worry about being nutrient deficient. Focus on moderation in all elements of your diet and free yourself of this needless concern. 

Foods That Cause Caloric Excess

There is no evidence that a particular food will cause weight gain or weight loss outside the law of calorie balance.

 When you consume more calories than your body uses in a day, you are in a caloric excess. A caloric excess that is sustained over a period of time will lead to weight gain and likely some of the related complications and health issues that come with obesity. There’s no doubt that this is something to be avoided and is perhaps the number one underlying cause of unsatisfactory health outcomes in the Western World. 

That said, any food can contribute to a calorie excess. No food can contribute more to this excess outside of its caloric value. (21) There is no evidence that a particular food will cause weight gain or weight loss outside the law of calorie balance. It’s about calories in vs calories out. (22)

You could eat a diet of nothing but chicken breast and broccoli and still be in a caloric excess if you eat too much of them. In that context, chicken breast and broccoli could be seen as “bad” for your health. You could eat a diet of nothing but coke, donuts, and burgers and still be in a caloric deficit – allowing you to lose weight. In that context, one could make the argument that those foods are being use in a “healthy” way. 

Some foods contain more calories and thus get labelled “bad” because they contribute more to your total daily calories than other foods, but this is an extremely narrow and in inaccurate viewpoint. 

Simply because a food naturally contains more calories than another doesn’t mean it’s unhealthy. It’s completely possible to eat that food as part of a calorie deficit if you wish without adverse side effects. It requires self-monitoring your food intake, which for some is more difficult than others, but is nevertheless achievable. (23)

Remember: Just because you have the potential to over-consume a particular food doesn’t mean that you will. (24)

As long as you find what you’re eating satiating and sustainable, then there’s absolutely no reason not to include higher calorie foods in your diet if you enjoy them. This is a point that many diets fail to illustrate – a fact that is often responsible for their high attrition rates. Being able to eat your favourite foods in moderation without guilt is a key to a successful long-term dietary strategy. 

While some people may find it either easier or necessary to consumer less calorie-dense foods in order to be satisfied, others may find it equally necessary to consume more calorie-dense foods in order to meet their needs (bodybuilders, endurance athletes, etc). (25-26) As with many things, your mileage my vary, and whether or not a food is appropriate for you depends on the context. Which brings me to my next point. 

Whether a Food is Beneficial or Detrimental to You Depends on Context, Not its Inherent “Cleanliness”

We’ve established that no foods have the ability to be bad for you outside the context of being part of a caloric excess and when consumed in moderation. That said, whether a particular food is helpful to you or not is dependent on who you are and how much of it you’re eating. 

As mentioned above, a serious athlete who is highly active will need more total calories in a day.  They can get away with more calorie dense foods that contain less micronutrients and often still feel satisfied and meet their daily micronutrient needs. 

In contrast, a sedentary person who spends their days in a cubicle might do well to eat less calorie dense foods that contain more nutrients. In extreme cases, doing so might be a necessity for that person in order to meet the recommended minimums of micronutrients while not being in an overall caloric excess. 

In trying to consider whether or not a certain food is appropriate for you, ask yourself:

  • Do I exercise?
  • How much do I exercise?
  • How many calories am I eating?
  • Am I aiming for a caloric excess, deficit, or to maintain my weight?
  • Will I still be able to be satiated if I eat it?
  • Do I have any medical conditions that might necessitate avoiding it?
  • Are you regularly meeting your macronutrient requirements?
  • Will eating it allow me to meet my micronutrient requirements while still hitting my body composition goals? 
  • Will eating that food cause excess unnecessary worry to you?

All of these questions are good and valid when deciding if your diet has room for something. However, in virtually all cases, your diet has room for some indulgences. 

The idea of clean eating is perpetuated by doctors, governments, trainers, athletes, gym bros, authors, gurus and more. 

The idea of ‘clean eating' has no objective definition and no empirical support in the research literature. 

If you take away anything from this article, it should be that certain foods don’t cause weight gain or harm to your health, rather, over-eating food (any food) causes weight gain and harm to your health. Recall:

There is no evidence that a particular food can cause harm when eaten in moderation.

Eating some less nutritionally dense foods will not cause a nutrient density.

Any food can contribute to a caloric excess when eaten in excess. There is no evidence that a particular food can cause harm when eaten in moderation. Click To Tweet

As usual, balance and moderation should take priority when considering what you eat. There’s no need to restrict anything if you don’t want to, and what matters most is to make sure you’re eating appropriately according to your particular context.

There is no such thing as unhealthy foods. Only unhealthy amounts. Click To Tweet



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3. Randomized controlled trial of changes in dietary carbohydrate/fat ratio and simple vs complex carbohydrates on body weight and blood lipids: the CARMEN study. The Carbohydrate Ratio Management in European National diets. Saris WH, Astrup A, Prentice AM, Zunft HJ, Formiguera X, Verboeket-van de Venne WP, Raben A, Poppitt SD, Seppelt B, Johnston S, Vasilaras TH, Keogh GF. International Journal of Obesity and Related Metabolic Disorders. 2000 Oct;24(10):1310-8

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8. http://ajcn.nutrition.org/content/88/5/1419.long

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12. Krissansen GW. Emerging health properties of whey proteins and their clinical implications. J Am Coll Nutr. 2007;26(6):713S–23S.

13. http://www.jpands.org/vol10no3/colpo.pdf

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17. McGregor RA, Poppitt SD. Milk protein for improved metabolic health: a review of the evidence. The Journal of Nutrition and Metabolism. 2013;10(46).

18.  Pfeiffer CM, Sternberg MR, Schleicher RL, Haynes BMH, Rybak ME, Pirkle JL. The CDC's Second National Report on Biochemical Indicators of Diet and Nutrition in the U.S. Population is a valuable tool for researchers and policy makers. J Nutr. 2013;143(6):938S–47S. doi:10.3945/jn.112.172858.

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20. Economos CD, Bortz SS, Nelson ME. Nutritional practices of elite athletes. Practical recommendations. Sports Med. 1993;16(6):381–399

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26.  Economos CD, Bortz SS, Nelson ME. Nutritional practices of elite athletes. Practical recommendations. Sports Med. 1993;16(6):381–399.

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