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Macmillan Childrens Publishing Group

Clean & Lean

30 Days, 30 Foods, a New You!

Ian K. Smith

St. Martin's Press




The concept of intermittent fasting (IF) is not particularly new, but over the last several years it has garnered a lot of attention and new research. It is what it sounds like—periods of fasting alternating with periods of non-fasting. While the vast majority of research has been conducted in animals, there have been more human-based studies the last couple of years that have analyzed the biological and physiologic changes that occur once a person participates in an IF program.

There are two major types of IF eating schedules. The first is the 5:2 schedule, where for five days a person eats how they typically would, then for two days of the week calories are restricted to 800 or less. The one caveat is that the fasting days should not be consecutive.

The second type of eating schedule, which you will follow on Clean & Lean, is time restricted feeding (TRF). On it, food is consumed only during certain hours and there are two periods of fasting. The duration of the feeding periods can vary. Most commonly, they are 8, 10, or 12 hours in length. For example, a 16:8 strategy includes 16 hours of fasting and 8 hours of feeding; the 14:10 strategy would be 14 hours of fasting and 10 hours of feeding.

The two IF eating schedules would look something like this:



Benefits of IF

Researchers acknowledge that while IF has been used for several years, and there have been studies performed to analyze the pros and cons of this eating strategy, much more work needs to be done to make validated, scientifically based claims. There have been, however, lots of anecdotal evidence about the effects of IF as well as animal studies and early human trials. While these observations are not always definitive and conclusive, they give us a clearer window through which we can inspect the potential benefits of this eating strategy. The evidence suggests that IF can help in weight loss, better regulate blood sugar levels, increase blood levels of human growth hormone, and induce cellular repair processes.

Potential Benefits of Intermittent Fasting

• Weight Loss

• Decreased Inflammation

• Improved Asthma-Related Symptoms

• Preserved Learning and Memory Functioning

• Decreased Belly Fat

• Reduced Insulin Resistance

Given the various research studies looking at IF, there are many theories that have been suggested as to why there might be appreciable physiological benefits. Mark Mattson, a senior investigator from the National Institute of Aging, has studied the hypothesis that during the fasting period cells are actually subjected to a mild stress. Mattson and others believe that cells react by making adaptations that increase their ability to handle this stress and possibly resist disease. It’s akin to the adage, “Whatever doesn’t kill you, makes you stronger.” In other words, fasting deprives cells of nourishment, which is stressful. But the cells change and adapt to handle tough conditions. Scientists believe that these changes make the cells tougher and better at preventing or fighting disease.

Intermittent fasting does not mean that you can simply eat whatever you want or how much you want during feeding times and still lose weight. One of the big misconceptions held by many people is that as long as they don’t violate their eating time parameters they can indulge in as many sweets, alcoholic beverages, or fried foods as they desire. Not only is this untrue, but it can potentially be very harmful to one’s health and efforts at losing or maintaining a healthy weight.

Calorie consumption still matters even while employing the IF strategy. For example, whether you consume 3,700 calories within a regulated 10-hour time span or throughout the day as is typical, the basic equation of weight loss still holds. Calories in must be less than calories out in order to lose weight. The vast majority of people who are consuming 3,700 calories are not going to lose weight regardless of the number of hours it takes to consume those calories. The body must do something with the caloric energy that is consumed. If you don’t burn off the calories, the body will store them in the form of fat, which will not only increase your weight but prevent you from attaining that leaner physique you’re trying to achieve.

Feeding Times

There are three TRF schedules that we will focus on in this book: 16 hours of fasting with 8 hours of feeding (16:8), 14 hours of fasting with 10 hours of feeding (14:10), and 12 hours of fasting with 12 hours of feeding (12:12). If you’re not sure which schedule will best fit you, try the 14:10 plan first. If it seems too difficult after a few days, then switch to the 12:12 plan. If it seems too easy, and you are up to the challenge, give the 16:8 a try. While the specific hours you choose to start and end your periods of fasting and feeding can change according to your preference, on the next page are samples of what a schedule might look like. You choose the feeding timetable that works best for you, but keep in mind that the smaller feeding window might produce better results.



I have designed Clean & Lean to be as accessible and versatile as possible. I don’t expect you to go to a grocery store and empty your bank account in order to find the items on the list. I don’t expect you to be locked into your house for the next thirty days so that you are in complete control of your food environment and all the ingredients that go into your food. You will be at work or at a restaurant or in an airport, and you still need to eat and not feel like you’re a criminal because you might have to slightly alter the plan. Remember, the purpose of Clean & Lean is to reintroduce your body to the wonders of clean eating and to give your organs a break from all the processed foods that dominate the choices in our stores and restaurants.

Clean food and clean recipes don’t have to be boring or flavorless, despite the image conjured of plain chicken and bland raw vegetables. In fact, clean foods can be just as tasty and exciting as those processed foods that are loaded with lots of additives and artificial flavor enhancers. Spices and clean condiments can go a long way to liven up recipes and thrill your palate. We have grown so accustomed to processed foods that we need to be reacquainted with the authentic flavors of real, natural food. So take your time with the ingredients. Taste them raw or with spices—something that will happen over the next thirty days.

I don’t like to use the word “rules,” because the mere mention of it inspires eye-rolling and rebellion and annoyance. Most people don’t like to be told what they can and can’t do as well as what they can and can’t eat. But in order for you to maximize your results and reset your experience for the next thirty days, I created guidelines that will give you the greatest chance of success and keep you most in line with the plan’s overall mission. A plan without any rules or guidelines would be a free-for-all, and it’s highly unlikely that would produce the results you’re seeking.

I have learned over the years that no chapter or book can answer all of the possible questions that come up. Just when you think you’ve covered all the bases, someone finds a topic or angle that hasn’t been addressed. I am not perfect, and this plan is not perfect. However, between the guidelines below and some common sense, the next thirty days should work well for you.

The key to success on this plan definitely lies in the departments of planning and preparation. Take a little time to think about what the next several days will look like: what meals you’ll be consuming and where they’ll be consumed. If you’re going to be traveling, take that into account and think about what foods will most likely be available to you while on the road. Plan accordingly.

1. No soda (regular or diet)

This is the biggest NO on the plan. Despite the taste that many enjoy, soda has absolutely no redeeming nutritional qualities at all. Full of sugar, artificial sweeteners, additives, and other mystery chemicals, it is like drinking fizzy poison. This goes for diet soda, too, which is equally filled with artificial ingredients. If soda is something you regularly drink, just cutting it out will make you feel like a new person. I have had hundreds if not thousands of people either write to me or tell me in person how cutting soda from their diet completely turned things around for them.

2. Only freshly squeezed juice

There is a thing called natural sugar. Sugar that is found in freshly squeezed juice comes just as nature created it. Yes, it’s still sugar, and yes, it still has calories, but it’s what comes with the sugar that makes the difference. Natural sugar does not prevent a food or drink from being clean; rather, it’s when the sugar is added that makes the difference. It’s what I call the “sugar package.” Vitamins and minerals and other phytonutrients come along with the sugar in fresh juice and are paramount at boosting our health. If you’re going to consume sugar, at least get some nutritional bang for your buck. One tip is, if it’s possible, get freshly squeezed juice that hasn’t been completely strained of the pulp and fruit skin, which contain lots of nutrients. Be careful of the labeling. For the purposes of Clean & Lean, you should not be drinking anything from concentrate or major manufacturer brands that just say “100% juice.” You should be looking for juices that are “freshly squeezed” and are labeled “no sugar added.” The ingredients should only list juice from fruit or fruits and in some cases water, but nothing else.

3. Canned and frozen are allowed

These items are allowed, but they must be clean. Nothing artificial is allowed, and the foods must be packaged in water or their natural juices. Something like canned tuna in water is completely fine, as are organic frozen vegetables and fruits. With anything canned or frozen, always be mindful of the sodium content, as it tends to be high, so opt for low-sodium options. Before turning your nose at frozen produce, you should be aware that the fresh fruit and vegetables you purchase at the store might not be as fresh as they look. In fact, a lot of produce is kept in storage for weeks at a time before it’s put out for retail. Some fruits and veggies can lose up to 75% of a certain nutrient after sitting in storage for a week or more; while they may look fresh externally, there’s internal degradation occurring the whole time thanks to enzymes that continue to work even after the fruit or vegetable is harvested. If you’re in the market for frozen produce, search for products that have been “flash frozen.” This means they have been frozen very quickly after being harvested, thus preserving the field-fresh taste and ensuring peak ripeness as well as the greatest nutrient density (more nutrients for fewer calories).

4. Unlimited water

Water is one of the most magical natural health-promoting wonders on earth. It comprises up to 70% of our body, and while it doesn’t contain the nutrients you find in food, it is essential for our very existence. It has no calories, helps energize muscles, keeps our skin looking good, helps our kidneys eliminate wastes, and gives a helping hand in maintaining normal bowel function. Most people don’t drink enough water, but for the next thirty days you’re going to find out what it feels like to really hydrate your body all the way down to the cells. Just because you drink to quench your thirst doesn’t mean you’re drinking enough. For the next thirty days you should be consuming between 8 and 10 cups per day. No water with artificial sweeteners or added chemicals. If you want sparkling water, that’s completely fine. If you want to squeeze some fresh citrus in your water, that’s fine too. Keep it natural and abundant and your body will be grateful.

5. No added sugar

While sugar is often vilified, and for good reason, it still plays an important role in our body. Glucose (sugar) is actually the number one source of energy for our brain. Glucose is important energy for our muscles and the billion cellular processes that take place in our bodies every second of the day. But we are consuming an extraordinarily dangerous amount that is taking a toll on our health. Added sugar is the biggest culprit—it’s the sugar you add to your foods at the table or that manufacturers slip into their foods while cooking or processing them. For the next thirty days, we are going to free our bodies of all this extra sugar, and you will notice the difference in your energy levels, complexion, and mood. The first few days might be challenging, but your body is an extremely adaptable machine and it will reconfigure so that in short order you will no longer crave that sweet stuff.

6. No artificial sweeteners

This should go without saying, but sometimes the most obvious things still need to be said. “Artificial” is a forbidden word for the next thirty days. While these sweeteners don’t have any calories, that’s the end of their good attributes. Scientists have raised all kinds of concerns, from them increasing your risk for something called the metabolic syndrome to increasing your affinity for or addiction to even sweeter foods. Avoid them at all costs and make sure you read the labels carefully, as manufacturers can be very tricky when including them on the labels for their products, making them difficult to identify.

7. Dairy is allowed

Dairy has been getting beat up lately, and I think it’s simply unfair. Sometimes dieting trends simply become too trendy for our own good. The wave of no-dairy sentiment is largely misplaced and for many people can be dangerous, as dairy provides nutrients that are critical to our overall health. Calcium, potassium, vitamin D, and protein are chief among these nutrients. Dairy is the primary source of calcium in our diets and is needed to build and preserve strong bones as well as teeth. Potassium is essential to life. Every time your heart beats it relies on potassium, which helps trigger the heart to pump and squeeze blood through the body. Potassium is also critical in helping our muscles move, nerves conduct electricity, kidneys filter blood, and blood vessels maintain blood pressure. Vitamin D works to maintain proper levels of phosphorous and calcium in the body: that’s why it’s an important component in building and maintaining healthy bones and teeth. It also plays a role in muscle function and keeping our immune system healthy. Dairy products such as yogurt, milk, and cheese (a great source of calcium, vitamin B12, and sodium) are rich in so many nutrients that make and keep us healthy. Some people may have an intolerance to lactose—the sugar found in milk and other dairy products—and need to be careful of which products they consume, but the vast majority of us don’t have this issue and can benefit greatly from the rich and easy offerings of dairy.

8. Fruits and vegetables are important

You might find yourself in a situation where you can’t find a food on your list because it’s simply not available. Not a problem. You are allowed to eat any fruit or vegetable even if they’re not on your list. You can eat them raw or cooked, but if they are going to be cooked, make sure that they are not cooked in anything but herbs and olive oil with some spices. You can add as wide a variety of fruits and vegetables as you like, even if it pushes your list beyond thirty. These power foods are the absolute essence of clean eating!

9. No MSG

Monosodium glutamate is the salt version of the amino acid glutamate. While MSG can occur naturally in foods such as tomatoes and cheeses, it is often synthesized in the laboratory for commercial reasons. This synthetic MSG is used around the world as a flavor enhancer, commonly added to canned vegetables, soups, processed meats, and Chinese food. While the FDA has classified it as a food ingredient that’s “generally regarded as safe,” it remains at the center of many a food controversy. There have been many anecdotal reports of reactions to MSG, including headaches, heart palpitations (rapid, fluttering heartbeat), nausea, chest pain, weakness, and sweating. If these reactions are actually due to the MSG, they have been mild and short-lived. The FDA requires that foods containing MSG list it in the ingredients label on the packaging as “monosodium glutamate.”

10. Not all salad dressings are created equally

It is better to make your own salad dressing for these thirty days, something that is not very difficult to do. However, you might not always be able to make it yourself or have access to it. In the event you find yourself in a situation where you must purchase dressing, it should only be organic, with no sugar added, and no artificial ingredients. Make sure the dressing is either fat-free or low-fat, but read the label, as manufacturers tend to sneak a lot of sugar and artificial ingredients into these dressings. Try to purchase dressing that has the fewest number of ingredients possible (five or fewer). The best bet is to make your own dressing, which will take few ingredients and not much time. Try the simple recipes here and here and you won’t have to worry about not finding the correct dressing at the grocery store.

11. No frying

We don’t want to take nature’s clean, health-promoting food and ruin all of the whole goodness that it brings. Deep-frying foods does just that and is counter to our mission. Yes, fried food tastes better to some, but so do grilled, baked, and sautéed foods. When food is fried, more calories are added to it, because the food absorbs the fat of the cooking oils. It’s okay to use olive oil to cook your food, as it is quite healthy and can enhance the nutritional value of your dish. However, cooking means sautéing your food or any preparation that is quick and doesn’t subject or saturate the food to sustained high heat for a long period of time—that is the equivalent of frying.

12. No white flour allowed/Whole-wheat flour is allowed

Flour is a perfect example of taking something completely nutritious and health-promoting and destroying it. The whole-wheat grain kernel is typically milled or processed (refined) and broken down into tiny pieces. In most instances, the process completely separates the three main parts of the kernel (bran, germ, endosperm). In the case of white flour, the endosperm is the only part of the three that is used, while the other two are thrown away. This basically means that the body will treat white flour as a starch and it will have similar effects in the body as eating refined sugar. Whole-wheat flour recombines the germ and bran with the endosperm further along in the process. While it is not perfect, it is more nutritious and better than white flour and is allowed.

13. Condiments with caution

Ketchup, mustard, mayonnaise, and salsa are allowed, but there’s a catch—the ketchup, mayonnaise, and salsa should be as clean as possible, and if you have the time, make them yourself to avoid mistakenly eating something that has been heavily processed. (See recipes, here, here, and here.) Mayonnaise will not keep for the entire thirty days—it will last up to a week—so you will have to make it a couple of times. Mustard is more difficult to make without using processed ingredients and the finished product can taste quite different from the mustards you’re accustomed to, so there is an allowance to purchase it. You can find several brands that make an organic product that doesn’t use sugar or anything artificial. Just look at the label and read the ingredients to make sure the brand fits Clean & Lean guidelines. If you must purchase your condiments, make sure they have very few ingredients, no sugar added, and no synthetic additives. You won’t always be able to choose the cleanest condiments due to the situation you might find yourself in, but do your best.

14. No alcohol

Alcohol is not exactly the devil, but it also is not the healthiest thing in the world. If you are trying to eat clean, you don’t want to add any more stress to your liver than necessary, especially since it’s already doing a Herculean job of scrubbing your blood of toxins. Yes, red wine can be healthy with its dose of the antioxidant resveratrol, but drinking too much of it and other types of alcohol can burden your body and impede it from carrying out many more important functions. But if you’re still looking for that resveratrol, you have options. You can find it in grapes, peanuts, blueberries, cranberries, and pistachios. If you don’t want to be a purist and must have alcohol, then a glass of red wine per day, or two natural, low-calorie beers every three days, won’t hurt. But remember: only one glass of wine or two beers.

Copyright © 2019 by Ian K. Smith, M.D.