Sunday, April 20, 2008

A Zone Primer

How do you get lean and alert?  The Zone is a strategy for eating that promises a longer and healthier life.  The key is to keep your insulin levels within a certain zone -- not too high and not too low.  The approach is to think of food as a "drug" and eat balanced meals of protein carbohydrates, and fats.  

I originally thought the Zone was a fad diet, but a colleague told me that it's actually based on science and results.  In fact, some Olympic athletes have used the Zone.  I then started researching the Zone to find patterns and practices for more effective eating strategies.  In this post, I summarize fundamentals of the Zone.  This post is based on the book,  The Top 100 Zone Foods: The Zone Food Science Ranking System, by Dr. Barry Sears.

You're Only as Good or Bad as Your Last Meal
According to Dr. Sears, your hormones are adjusted at every meal:

To enter the Zone, you need to learn how to maintain the hormones produced by the foods you eat within a Zone (not too high, not too low).  These hormones are readjusted every time you eat a meal or snack, so you're only as good or as bad as your last meal.  This means that if you splurge and eat too many carbohydrates in one sitting, you can get back into the Zone the next time you eat.  Thus you don't need to feel guilty about cheating.  Just make your next meal Zone-friendly.

The Zone is a Precise Medical Definition
Dr. Sears writes that the Zone is a precise medical definition:

The Zone is not some clever marketing phrase.  The Zone has a very precise medical definition that can be measured with a simple blood test.  The next time you have a blood test, ask your doctor to measure your fasting insulin levels.  If your insulin levels are too high (greater than 10 uU/ml), you know that you're not in the Zone.  The sluggishness, hunger, and moodiness you feel in between meals are all signs that you're out of the Zone.

Food is Your Key Drug
According to Dr. Sears, food is your key drug for controlling your insulin:

You can lower your insulin levels to get into the Zone.  The only "drug" that can take you there is food.  In the process, you'll radically improve your quality of life.  You'll feel less tired, more mentally charged, and happier throughout the day.  Your new hormonal balance will be giving your body the continuous fuel it needs to keep all your systems operating at their peak performance.  You will feel your body tell you that "all systems are go" and that the possibilities of what you can do are limitless.

Wipe Away the Myths
Dr. Sears writes that you have to reexamine what you know about nutrition:

How can you gain control of your unruly hormones?  You need to wipe away many of the nutrition myths that you've probably come to believe -- for example, that fat is bad and pasta is good.  You need to stop fooling yourself into thinking that you can lose weight while eating fat-free cookies or fat-free ice cream.

Balance and Quality
Dr. Sears writes that the key to the Zone is balancing protein, carbs, and fats and choosing higher quality foods:

You need to embrace the notion that you must have a balance of the three major categories of food (protein, carbohydrates, and fat) at every meal to get the right response from your body.  You also need to be selective about the quality of the foods you choose within each category to get the most hormonal cluck for your buck. ...  Get the right balance and quality of foods, and your body will produce the appropriate hormonal signals for the next four to six hours.  During this time, you will be in the Zone.  You can keep yourself there by eating the same balance of foods at your next meal or snack.  But you still need to be selective about the quality of foods you choose within each category.

Seven Rules of the Zone
Dr. Sears provides seven rules for the Zone:

  • Rule 1.  Always eat a Zone meal within one hour of waking.
  • Rule 2.  Every time you eat, go for a Zone balance of protein, carbohydrates, and fat.
  • Rule 3.  Try to eat five times a day: three Zone meals and two Zone snacks.  Afternoon and late evening snacks (which are really Zone mini-meals) are important to keep you in the zone throughout the day.
  • Rule 4.  Never let more than five hours go by without eating a Zone meal or snack -- regardless of whether you are hungry or not.  In fact, the best time to eat is when you aren't hungry because that means you have stabilized your insuline levels.
  • Rule 5.  Eat more fruits and vegetables (yest, these are carbohydrates) and ease off the bread, pasta, grains, and other starches.  Treat these low-quality carbohydrates like condiments.
  • Rule 6.  Drink at least eight 8-ounce glasses of water every day.
  • Rule 7.  If you make a mistake at a meal, don't worry about it.  There's no guilt in the Zone.  Just make your next meal a Zone meal to get you where you (and your hormones) belong.

Divide Your Plate in Three (The Hand-Eye Method)
Dr. Sears provides a simple way to divide your plate to create a Zone friendly meal:

Divide your plate into three portions.  On one-third of your plate, choose a low-fat protein portion.  It should be no bigger than the size and thickness of your palm.  Then fill the other two-thirds of your plate with high-quality carbohydrates (vegetables and fruits).  Add a dash (that's a small amount) of "good" fat to complete your Zone plate.

Zone Food Block method
For those that want a more precise way of measuring your meal, Dr. Sears provides the Zone Food Block method:

You may find that creating Zone meals using the hand-eye method described earlier works well to get you into the Zone.  Some people don't like to estimate portion sizes, however, and would prefer a more scientific way of measuring out carbohydrates, protein, and fat.  If you are one of these people, you should consider using the Zone Food Block method.  ... Instead of using your plate as a guide, you'll be counting out blocks of protein, carbohydrates and fat. 

Protein Block, Carbohydrate Block, and Fat Block
According to Dr. Sears, the Zone Food Blocks are as follows:

  • Protein Block.  One Protein Block contains 7 grams of protein.  The average male needs four Protein Blocks and the average woman needs three Protein blocks.  
  • Carbohydrate Block.  One Carbohydrate Block contains 9 grams of carbohydrates.  3 Carbohydrate Blocks would contain 27 carbohydrates.  4 Carbohydrate Blocks would contain 36 carbohydrates.
  • Fat Block.  One Fat Block contains 3 grams of fat.  3 Fat Blocks would contain 9 grams of fat.  4 Fat Blocks would contain 12 grams of fat.

Key notes about the Zone Food Blocks:

  • The number of Protein Blocks you need depends on whether you are a man or a woman.
  • Eat the same number of Carbohydrate Blocks at every meal as Protein Blocks.
  • Eat the same number of Fat Blocks at every meal as Protein Blocks.

The "1-2-3" Method
Dr. Sears writes that you can think of the Fat Block as the "1-2-3" Method:

Each fat block contains 3 grams of fat, so you'll get 9 grams of fat in three blocks and 12 grams in four blocks.  Another way to think of this is to use the "1-2-3" method.  Plan to have 1 gram of fat for every 2 grams of protein and 3 grams of carbohydrate.  A typical Zone meal for a woman would contain 10 grams of fat, 20 grams of protein, and 30 grams of carbohydrate.

The Average Woman Zone Food Blocks
According to Dr. Sears, a typical Zone meal for a woman would contain about 9 grams of fat, 21 grams of protein, and 27 grams of carbohydrates.

  • 3 Protein Blocks.  The average woman will need three Protein Blocks for each meal (21 grams of protein.)  That translates into about 3 ounces of high-quality protein.
  • 3 Carbohydrate Blocks.  The average woman will need three Carbohydrate blocks for each meal (27 grams of carbohydrates.)
  • 3 Fat Blocks.  The average woman will need three Fat Blocks (9 grams of fat.)

The Average Male Zone Food Blocks
According to Dr. Sears, the typical Zone meal for a man would contain about 12 grams of fat, 28 grams of protein, and 36 grams of carbohydrates.

  • 4 Protein Blocks.  The average man will need four Protein Blocks for each meal (28 grams of protein.)  That translates into about 4 ounces of high-quality protein.
  • 4 Carbohydrate Blocks.  The average man will need four Carbohydrate Blocks for each meal (36 grams of carbohydrates.)
  • 4 Fat Blocks.  The average man will need four Fat Blocks for each meal (12 grams of fat.)

Three Steps to a Zone Meal
Dr. Sears outlines the three steps to a Zone meal:

  • Step #1. Start with Protein
  • Step #2. Balance with Carbohydrates
  • Step #3. Add Fat

Step #1.  Start with Protein
Dr. Sears writes:

The first step of Zone meal preparation is never to consume any more low-fat protein than you can fit in the palm of your hand or that is any thicker than your hand.  For the average American female, this amount is 3 ounces of low-fat protein, and for the average American male it is about 4 ounces.  Unless you are active, your body can't utilize any more protein that that at a single sitting, and any excess protein will be converted to fat.

Your body needs a constant supply of dietary protein to replace the protein that is lost from your body on a daily basis.  What's more, eating protein stimulates the release of the hormone glucagon, which has a hormonal effect opposite to that of insulin.  Glucagon tells your body to release stored carbohydrates from the liver to replenish blood sugar levels in the brain.  Without adequate levels of glucagon, you'll always feel hungry and mentally fatigued because your brain is short on its primary fuel -- blood sugar.

Step #2. Balance with Carbohydrates
Dr. Sears writes:

Once you have the protein portion of your meal, you need to balance it with carbohydrates.  Remember: fruits and vegetables are carbohydrates.  In fact, they are the highest-quality carbohydrates you can eat, which is why (with one or two exceptions) they are the only carbohydrates you'll find on my Top 100 list.  The reason you won't find pasta, rice, or mashed potatoes on my list is that they wreak havoc on your body without providing much nutrition.  First of all, these carbohydrates  in cause dangerous spikes in your insulin levels, which cause your blood sugar levels to rise and then quickly fall, leaving you famished just two hours after eating.  Second, these carbohydrates contain very few vitamins and minerals (unless they're artificially fortified) and only sparse amounts of phytochemicals, the tiny plant chemicals that can ward off cancer, heart disease, and other illnesses by acting as powerful anti-oxidants.

On the other hand, fruits and vegetables meet both of my criteria for high-quality foods.  They are packed with natural vitamins, minerals, and phytochemicals.  They also contain fiber, which slows the release of insulin so you won't get quick spikes in your blood sugar.  This is why an apple leaves you feeling satisfied longer than a cookie.  not all carbohydrates are equal in their ability to stimulate the production of insulin.  The high-quality carbohydrates are favorable in that they have the capacity to stimulate insulin: others are unfavorable in that they have a high capacity to stimulate insulin.

Step #3: Add Fat
Dr. Sears writes:

Now your plate is completely covered.  Protein takes up one-third of the space, and carbohydrates take up the other two-thirds.  Where does fat fit in?  Fat is the sprinkling that seasons your foods -- whether it's the teaspoon of olive oil that you cook your vegetables in or the avocado slices or handful of slivered almonds that you add to your salad.  Without fat, you can't have a complete Zone meal.

Fat has no direct effect on insulin, nor does it have any effect on glucagon.  Fat, though, acts like a control rod in a nuclear reactor, slowing the rate at which carbohydrates enter your bloodstream.  In addition, it also causes the release of another hormone that tells your brain to stop eating.  Finally, fat gives you a feeling of satiety and helps blend the flavors that give great meals their exquisite taste.

The high-quality fats that make my Top 100 list are those that are good for your heat and your health in general.  These are the monounsaturated fats and long-chain Omega 3 fats.  You get monounsaturated fats from olive oil, select nuts, and avocados.  Long-chain Omega-3 fats come from fish and fish oils (like the cod liver oil your grandmother told you to take).  These are exceptionally powerful allies in your quest for a longer life.

The fats that are absent from my Top 100 are the saturated fats, trans fats, and Omega-6 fats.  You find saturated fats in margarine and other partially hydrogenated oils found in many processed snack foods.  Polyunsaturated fats like corn and safflower oil are rich in Omega-6 fats, which in excess are far worse for you hormonally than saturated fats.  I consider these Omega-6 fats to be really "bad" fats because they can lead to increased inflammation, which is an underlying cause of heart disease and arthritis.

Zone Meal Timing
Dr. Sears provides an example of meal timing to stay in the Zone throughout your day:

Meal Timing Approximate Time
Breakfast Within 1 hour after waking. 7:00 A.M.
Lunch Within 5 hours after breakfast. 12:00 P.M.
Late-afternoon snack Within 5 hours after lunch. 5:00 P.M.
Dinner Within 2-3 hours after snack. 7:00 P.M.
Late-night snack Before bed. 11:00 P.M.

A Day in the Zone
Dr. Sears provides an example day in the Zone:

Meal Example
Breakfast A six-egg-white omelet mixed with some asparagus and 2 teaspoons of olive oil; 2/3rd cup of slow-cooked oatmeal; and a cup of strawberries.
Lunch Orange, tofu, and spinach salad: 1 pound of baby spinach leaves mixed with orange slices and 4 and 1/2 ounces of smoked tofu, topped with plum vinegar and 1 and 1/3 teaspoons of sesame oil; a piece of fruit for desert.
Late-afternoon snack Two hard-boiled eggs with the yolks removed and replaced with hummus (mashed chickpeas and olive oil).
Dinner A 5-ounce piece of salmon covered with a tablespoon of slivered almonds; three cups of steamed vegetables; a cup of mixed berries for desert.
Late-night snack A 1-ounce piece of soft low-fat cheese and a glass of wine (or a small piece of fruit if you don't drink).

You'll Lose Weight and Live a Longer Life
Dr. Sears writes:

Just glancing through this, you should notice that it's a lot of food.  That's because you're eating low-density carbohydrates in the form of fruits and vegetables.  On a volume basis, fruits and vegetables contain much fewer carbohydrates than high-density bread and pasta.  This means you get more food in fewer calories.  For this reason, women typically eat only about 1,200 calories a day on the zone and mean only about 1,500 calories per day.  This is what I call the Zone paradox.  You can consume a lot of food without getting a lot of calories or feeling hungry or deprived.  You will also lose weight, which is an added plus.  Most importantly, if you eat only Zone meals and snacks, you are greatly increasing your chance for a longer life by keeping your overall calorie count at a level that has been shown by 60 years of research to be the only way to reach your maximum longevity.

Key Take Aways
Here's my key take aways:

  • You're only as good or bad as your last meal.  I really like this idea of eating thinking one meal at a time.  Your hormones readjust every time you eat, so each meal is a new chance for you to get in the Zone.
  • Your insulin levels influence your quality of life.  Your hormones influence your thinking and feeling.  They also influence your ability to have a long and healthy life.
  • Food is the key drug that controls your insulin levels.  Your food choices impact your insulin.
  • The key to the Zone is balancing carbohydrates, proteins and fats.  To be in the Zone, you need to balance your carbohydrates, protein and fats. 
  • Choose higher-quality foods over lower-quality foods.  You need to choose higher-quality foods over lower-quality.  For example, choose fibrous carbohydrates over starchy carbohydrates.  Avoid foods that have a high glycemic impact.
  • For a Zone meal, divide your plate in three.  For 1/3rd of your plate, choose a low-fat protein (chicken or fish.)  For 2/3rds of your plate, choose fibrous carbohydrates (fruits and vegetables.)
  • Think in protein, carbohydrate, and fat blocks.  A Protein Block is 7 grams of protein, a Carbohydrate Block is 9 grams of carbohydrates, and a Fat Block is 3 grams of fat.
  • Men need 4 blocks of protein, carbohydrates, and fat.   This translates to 12 grams of fat, 28 grams of protein, and 36 grams of carbohydrates.
  • Women need 3 blocks of protein, carbohydrates, and fat.  This translates to 9 grams of fat, 21 grams of protein, and 27 grams of carbohydrates.
  • Choose "good" fats over 'bad" fats.  Choose monosaturated fats and long-chain Omega 3 fats over saturated fats, trans fats, and Omega-6 fats.

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3 comments:

Anonymous said...

J.D,

What a comprehensive post. Great overview of the Zone.

I tried the Zone years ago, and it was actually an easy diet to follow. I would say the hardest part was the timing of the meals. I would get busy and forget to eat. I ended up using a small timer. Within three days I felt great and was successful at losing pounds too.

There's a lot of truth to keeping your insulin levels in check.

Anonymous said...

JD,

What about fiber? I heard that fiber is equally important in the cleansing action of body, mainly colon. I agree with Barbara that it is difficult to keep up with five meal idea considering what life demands on a daily basis. Nonetheless, great article. Very informative.

Thanks
Shilpan

J.D. Meier said...

@Barbara - Thanks. Now that you mention it, timing meals is trickier than I expected. I thought I ate more routinely than I actually do. It's funny what shining a spotlight reveals. It got me thinking again about how I structure my day. I need to mess with my routines a bit to see if I can better synchronize with a more effective me.

@Shilpan - Funny you should mention it -- I'm a fan of fiber. I cheat though -- I drink a powerful, ancient Chinese secret every morning.