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Macmillan Childrens Publishing Group

The Clean 20

20 Foods, 20 Days, Total Transformation

Ian K. Smith

St. Martin's Press



I was in the gym in the middle of my workout when the idea for The Clean 20 came to me. I had spent the previous afternoon with a friend of mine and she was telling me about how sluggish she sometimes felt and how she would love to “get her body back.” She had been experimenting with different types of foods to see if she could boost her energy levels, lose weight, and increase her overall sense of feeling good. I’d heard this exact situation described by many people throughout my travels making appearances talking about health and wellness. But the conversation with my friend really struck home for me. On the outside she was pretty, not overweight at all, and seemed to be so much in her groove. But inside there was conflict and doubt and a real struggle that was not allowing her to feel her best or how she knew she could feel.

So there I was in the gym the next morning and she sent me a text. I told her that I had done some research and that I felt comfortable I could customize a meal and exercise plan that could help her. While food can’t solve all of our problems, it can solve a lot of them or at least start pointing us in the right direction. The right foods really have medicinal properties. Food can truly affect your physiology—how your body works—and how it interacts with the environment.

The other part of the conversation with my friend centered on exercise. She was exercising, but she was inconsistent, and in my opinion she wasn’t doing the optimal exercises to achieve the results she desired. I realized that the foods she was eating or not eating were affecting her energy level and this was in turn affecting her motivation to exercise. It’s one of those “which came first, the chicken or the egg?” but it was all making sense to me. She needed to spend less time exercising, but more time exercising efficiently. The hours she spent in the gym didn’t matter, but how she spent them could make all the difference in the world.

I modified her exercise plan to go along with her custom-built meal plan. I figured she only needed twenty major foods to fuel her transformation and she needed only twenty minutes of efficient exercise five times a week to synergize with her improved nutritional intake. The Clean 20 is an expanded version of her plan. There is nothing arbitrary about it, as it is all backed up by science and research. So much of what we put into our body in the form of food or drink is either harmful or counterproductive. We make our bodies work overtime to metabolize and process these foods. We also hamper the body’s ability to function at its best. With The Clean 20, you are going to change things around and give your body what it needs to operate like the magnificent machine it was built to be. In just twenty days you will have a physical, mental, and spiritual transformation that can last you a lifetime!

Ian K. Smith, M.D.

April 2018


What Is Clean Eating?

Clean eating is a concept and term that has been around for decades but has become fashionable in the last several years as health trends in general have gained popularity from being promoted in reality shows to fitness centers to tiny kitchens across the country. In its simplest form, clean eating is based on the basic premise that eating more natural, less-processed foods is not only good for one’s health, but equally important for the environment. Food that crosses our table in a form closest to what it looked like coming out of the ground or off a tree has been considered to be the healthiest and the natural order of humankind’s engagement with the environment. Free of chemicals, artificial ingredients, and other potentially toxic additives, clean food represents the best there is to nourish and fuel our bodies.

The clean-eating movement, like any other popular trend (paleo, gluten-free, raw) has not been immune to detractors who claim that it unfairly demonizes certain food groups, takes the concept of avoiding processed foods to the extreme, is too expensive, and is impractical for most people to follow for an extended period of time. It has given birth to many derivative programs that fall under the general category of clean eating but have subtle and sometimes major differences in philosophy and execution strategies. Ask fifteen nutritionists to define clean eating and you are likely to get fifteen different answers. But there is a theme that runs through most of these answers, a common core that gives form to the basic concept of eating foods in their most natural state with as little manipulation as possible.

In The Clean 20, I will set forth some basic clean-eating principals that will serve you well and help you make informed decisions when it comes to nourishing the world’s most awesome machine—your body. Clean eating is not at all about perfection. It is not about a rigid, dense cadre of rules and penalties that must be strictly adhered to in order to benefit from the tremendous health value of food. Clean eating can benefit all of us and at the same time not be overly expensive, overly restrictive, or inaccessible. Remember that some of a good thing is still better than none of a good thing, and to think harshly of those who do not believe in austere eating principles is a misplaced judgment.

Reducing Processed Foods

Despite what some purists think, not all processed foods are bad for you and some processed foods still can fall under the category of clean foods. The term “processed” is considered to be the equivalent of unhealthy by many, and for good reason. Take grains, for example. In their processing methods, manufacturers will take the whole grain and refine, mill, or process it by taking away part or parts of the three-part grain (bran, endosperm, germ). This could mean losing as many as fifteen or more different nutrients. Once the manufacturers have stripped the grain, they then use a process to add some—but not all—of the nutrients back. This is where the word “enriched,” which you may have seen on bread or cracker packaging, comes from. This is why it’s better to choose an “unrefined” grain over a “refined” grain and it’s important to pay attention to labels such as “100% whole grain” or “100% whole wheat.” When it comes to bread, that 100% makes a big difference. Multigrain might seem like the same thing, but it’s not: multigrain simply means many grains. This is not a guarantee that grains are whole. You could still be eating many grains that are refined.

There is no hard and fast rule when it comes to how many ingredients should be in a clean food, but many nutritionists suggest that if a product has more than five or six ingredients, then it’s likely not to be very “clean.” It’s easy to look at the food label and check the ingredients list. If a package does not have a list of ingredients and you aren’t certain of what it contains, it’s prudent to either confirm the information or approach the product with a fair degree of caution.

Decreasing Added Sugars

Plenty of foods naturally contain sugar. Fruits, for example, should be part of the foundation of any good eating regimen, and many fruits contain lots of natural sugars. (Some have less sugar: apples, avocados, blackberries, grapefruit, peaches, oranges, raspberries, strawberries.) What a lot of people don’t know is that many vegetables also naturally contain sugar. Peppers, carrots, parsnips, radishes, squash, potatoes, corn, and peas are just a few examples of sugar-containing vegetables. Demanding all clean foods be free of sugar is nonsensical, as that would mean eliminating fruits and vegetables that are the staples of any healthy diet.

But what does make sense is eliminating foods that have added sugars. In the course of processing foods, manufacturers are keen to add sugar to the mix. This makes complete sense from a business perspective, as sugar is highly satisfying to the palate and addictive. If people like the sugar and it will sell, then give them the sugar; health consequences typically take a back seat to the financial concerns. The major food and beverage sources that contain added sugars include candy, cakes, cookies, donuts, pastries, sweet rolls, pies, sodas or soft drinks, energy drinks, sports drinks, and fruit drinks such as fruitades and fruit punch.

A study published in JAMA Internal Medicine found that added sugars make up at least 10% of the calories the average American eats in a day. But approximately one in ten people get an enormous 25% of their calories from added sugar. Why does this matter? Because the findings of this study were earthshattering. Over the course of this fifteen-year study, participants who took in 25% or more of their daily calories as sugar were more than twice as likely to die from heart disease compared to those who included less than 10% added sugar in their diets. The study went one step further and concluded that the odds of dying from heart disease rose in tandem with the percentage of sugar in the diet, something that was true regardless of a person’s age, sex, physical activity level, or body-mass index (BMI).

It’s important when looking at labels to be able to identify these added sugars. The ingredients list is created in a specific way. Ingredients are listed in descending order, which means the closer it is to the front of the list the higher a percentage it is in the food. But you must be careful. Just because you might see sugar listed as the fifth ingredient doesn’t mean it is not the ingredient with the highest percentage. Sugars have lots of different names, many of which you are not going to recognize. So, if the ingredients list has corn syrup as number three, dextrose as number five, cane sugar as number six, and malted barley as number eight, then there’s a good chance that when you add all of those together, they will actually make sugar the number one ingredient.

Identifying these sugars and sorting through all their confusing names can be very tricky. Here is a good list to use, but note that there are other names manufacturers might be using to sneak that sugar into your food. This list is not comprehensive, but it is a great place to start:

anhydrous dextrose

brown sugar

cane sugar


confectioners’ powdered sugar

corn syrup

corn syrup solids



evaporated cane sugar







high-fructose corn syrup (HFCS)



invert sugar



malted barley



malt syrup


maple syrup



nectars (e.g., peach nectar, pear nectar)

pancake syrup



raisin syrup

raw sugar


rice malt

rice sugar







white granulated sugar



Reducing Unnecessary Additives

“Additive” is a term that encompasses an extremely large number of food ingredients. In its simplest and broadest definition, a food additive is any substance that is added to food. Its more legal definition: “any substance the intended use of which results or may reasonably be expected to result—directly or indirectly—in its becoming a component or otherwise affecting the characteristics of any food.” Direct food additives are those that are added to a food for a specific purpose in that food. Xanthan gum is a good example, as it’s often used in foods such as bakery fillings, puddings, and salad dressings to add texture and prevent ingredients from separating. Most direct additives are identified on ingredient labels.

Indirect food additives are those that become part of the food in very small amounts due to the process of packaging, storing, or other handling methods. Regardless of how sanitary or expertly manufactured, small amounts of substances that are part of packaging can actually end up in the food. This is why food packaging manufacturers are required to prove to the U.S. Food and Drug Administration (FDA) that all materials that come into contact with the food are safe before they’re allowed to be used.

Most food coloring or color additives certainly do not pass muster for a food that is considered to be clean. (There are, however, some natural colorings such as annatto, betanin, cochineal extract, carmine, and chlorophyllin that would meet the clean eating standard.) These coloring additives are dyes, pigments, or substances such as Blue No. 1, Blue No. 2, and Red No. 3 that are capable of imparting color when added or applied to a food, drug, cosmetic, or human body. Without color additives, colas wouldn’t be brown and mint ice cream wouldn’t be green. Almost all the processed foods we eat contain some color additives. In fact, without color additives we wouldn’t recognize the vast majority of the foods we are accustomed to eating.

Food preservatives are natural or man-made chemicals that are added to foods to stop them from spoiling. Preservatives have been used for centuries, most famously salt to preserve fish and meats. Preservatives often have an acidic quality and largely work by preventing the growth of organisms such as molds, yeast, and bacteria. Without preservatives, our food would spoil quickly and be overrun with microorganisms that could cause illness if consumed. There is a surprisingly large number of foods that contain preservatives, everything from soft drinks to cheese, dried fruit to processed meats. While some preservatives are necessary to sustain food, there is plenty of preservatives, such as monosodium glutamate (MSG), propyl gallate, potassium bromate, and many more, that could have harmful health consequences.

Try to limit the amount of preservatives in your food; start by reading the nutrition labels carefully. Cleaner foods don’t have these additives, so it’s true that in general they might spoil faster than processed foods. But this is not a reason to choose the additive-rich foods. Making smart choices at the right time of the season means you will still be able to purchase clean products that will last at least through most of the week, thus reducing the need for you to go grocery shopping multiple times in a single week.

Following is a list of commonly used preservatives that you should try to avoid. By no means is this a comprehensive list, but it is a good place to start:

butylated hydroxyanisole (BHA)

butylated hydroxytoluene (BHT)

potassium benzoate

propyl gallate

sodium benzoate

sodium nitrate

tertiary butylhydroquinone (TBHQ)

The FDA is responsible for regulating food coloring as well as other additives, but the FDA is not perfect and has its limitations with regard to budget and other resources. Its major goal is to make sure that these additives are generally regarded as safe. However, expecting a single governmental agency to be able to know everything there is to know about these ingredients and their long-term health implications is unrealistic. In fact, these safety clearances are quite dynamic, as new information and studies may emerge that show that something previously listed as safe is no longer as safe as once thought. Ingredients are constantly coming on and off the list of accepted additives or finding themselves under additional review. So, while the FDA is a good place to start when trying to ascertain the safety of additives, finding other resources is necessary for a more exhaustive analysis.

Clean eating is all about knowing what you’re putting in your body and the impact foods and beverages can have on not just your health, but your mind and overall functioning. It comes down to making smarter, strategic choices, being aware not only of the ingredients you’re consuming but how these ingredients are harvested, processed, and packaged. The overall goal is to consume minimally processed foods that are nutritionally dense (relatively rich in nutrients for a lower number of calories), affordable, tasty, and good for the environment. Clean eating can be not only a blueprint for the next twenty days, but one you can follow for the rest of your life.

Copyright © 2018 by Ian K. Smith, M.D.