Carbohydrate Intolerance

The following information is taken entirely from Phil Maffetone’s post Carbohydrate Intolerance and The Two Week Test.

Many people suffer from a condition known as carbohydrate intolerance, or (CI). This is perhaps the most well-hidden epidemic of our time and is being made worse by the prevalence of sugar and other high-carbohydrate foods common to our diets.

Carbohydrate Intolerance — and the full spectrum of ailments that accompany it — begins as a hidden problem. CI then progresses to a functional disorder producing symptoms, such as fatigue, that negatively affect quality of life. Gradually, this process generates serious illnesses such as diabetes and heart disease.

While best viewed as a single, escalating progression of the same problem, carbohydrate intolerance has series of distinct stages:

Early stages

The symptoms can be elusive, often associated with difficult-to-diagnose blood-sugar problems, fatigue, intestinal bloating and loss of concentration.

Middle stages

The worsening condition is known in the medical community as carbohydrate-lipid metabolism disturbance or hyperinsulinism. It causes more serious conditions such as hypertension, it elevates triglyceride levels and LDL “bad” cholesterol while lowering HDL “good” cholesterol, and increasing body fat.

Final Stages

CI manifests as an array of more serious problems, including obesity, and various diseases such as diabetes, cancer and heart disease. These end-stage conditions are part of a set of diseases that are now well-recognized by modern medicine. They are referred to as Syndrome X, or Metabolic Syndrome.

Taking the Carbohydrate Intolerance survey is the first step in reclaiming your optimal health. The next step is taking the Two-Week Test, which will help determine just how sensitive your body is to carbohydrates.

The Two-Week Test

This evaluation will tell you if you are carbohydrate-intolerant, and if so, how to remedy it. It must be emphasized that this is only a test and not a permanent diet — it will only last two weeks and should not be pursued beyond this 14-day period. You should never experience hunger during the test — you can eat as much of the non-carbohydrate foods as you want, and as often as you need.

Of all the clinical tools I developed and used for assessment and therapy through my career, the consistency of results from the Two-Week Test surprised me the most. It’s amazing how a person can go from one extreme of poor health to vibrant health in such a short time. It’s simply a matter of removing a major stress factor — refined carbohydrates and excess insulin — and allowing the body to function the way it was originally meant.

The Two-Week Test was unique because it required individuals to take an active role the process of self-evaluation. He or she would actually feel what it was like to have normal insulin levels, optimal blood sugar and, in many cases, be finally free of signs and symptoms associated with CI — all within a short time frame. This proved to be a far superior method of educating the patient.

Some people didn’t feel improvement because they were not carbohydrate-intolerant. But patients who were overweight, had blood-sugar problems, and simply could not escape the damage of eating refined carbohydrates now knew what it would take to quickly change their health.

It is not the purpose of the Two-Week Test to restrict calories or fat. It merely restricts many carbohydrate foods. For a period of two weeks, just eat as much as you want from what you’re allowed, and avoid what’s restricted.

Let’s summarize the basics of the Two-Week Test:

  • Write down a list of all your signs and symptoms.
  • Weigh yourself before starting.
  • Always eat breakfast.
  • Plan your meals and snacks — buy sufficient foods allowed on the test, and get rid of those not allowed so you’re not tempted.
  • Eat as much and as often as necessary to never get hungry.
  • After the test, re-evaluate your signs and symptoms, including weight.
  • Begin adding natural, unprocessed carbohydrates to every other meal or snack, and evaluate whether this causes any of your previous signs and symptoms to return.

The following sections discuss each of these steps in more detail, in order to help you through the testing process.

Before The Test

  1. Record health problems. Includes any symptoms or ailments that you might have, such as insomnia or fatigue. This may take a few days since you might not recall them all at once. You will review these complaints after the test to see which ones have and haven’t improved.
  2. Weigh yourself. This provides another important sign of how your body is working, especially after the test. This is the only instance I recommend using the scale for body weight—it’s not a measure of body fat, but it is a good pre/post evaluation. You may lose some excess water (which will show on the scale), but your fat-burning will increase and you’ll start losing body fat (which won’t show on the scale). I’ve seen some people lose anywhere between a few and 20 pounds during the test.
  3. Stock up on the right foods. Before you start, make sure you have enough of the foods you’ll be eating. (Suggestions listed below.) In addition, go through your cabinets and refrigerator and get rid of any sweets, foods containing them, and all breads and products made from refined flour. Otherwise, you’ll be tempted to eat them if you get cravings during the test.
  4. Plan Correctly. Schedule the test during a two-week period in which you are relatively unlikely to have distractions. (It’s a bad idea to do the test during holidays, for example.) Don’t worry about cholesterol, fat or calories, or the amount of food you’re eating. This is only a test, not the way you’ll be eating forever.
  5. Most importantly, eat breakfast within an hour of waking.

Following the test for less than two weeks probably will not give you a valid result. So, if after five days, for example, you eat a bowl of pasta or a box of cookies, you will need to start the test over.

During The Test: The Menu

What makes the Two-Week Test foods acceptable aren’t the foods themselves, but rather their properties. It’s all about eating unprocessed “real” foods that are low in carbohydrates. You can assume any foods that are similar to what you find on this list can be eaten. If you see any foods on this list or the following that are disallowed (e.g. potatoes), you can assume that similar foods (sweet, russet, and gold potatoes and yams) also cannot be eaten.

YES Foods

You MAY eat as much of the following foods as you like during the Two-Week Test.

Plant Foods

  • Raw and cooked vegetables: Tomato, onion, garlic, greens such as spinach, kale, chard, and all lettuces, broccoli, cauliflower and Brussels sprouts (for those with thyroid dysfunction, cabbage-family veggies are best eaten thoroughly cooked), carrots, zucchini, etc.
  • Tree nuts (and nut butters): Macadamia, almond, walnut, for example. (Does NOT include peanuts or cashews).
  • Coconut:  cream, oil, milk and flour.

Animal Foods

  • Beef: Look for organic, grass-fed varieties.
  • Turkey: organic.
  • Lamb: Look for organic, grass-fed varieties.
  • Fish: Wild-caught cold water fish (tuna, salmon, etc) are best.
  • Eggs.
  • Shellfish.


  • Unprocessed Hard Cheeses: Cheddar, asiago, parmesan, etc.
  • Unprocessed Soft Cheeses: Feta, brie, camembert, mozzarella, etc.
  • Cream: Heavy cream, sour cream, full-fat crème fraiche.


  • Oils: Avocado, coconut, and olive oil.


  • Vegetable Juice.
  • Coffee or tea: If you usually drink it.
  • Vinegar: balsamic, apple-cider, etc.
  • Pure, distilled spirits: Small amounts of gin, vodka, whiskey.
  • Dry red wines: Cabernet Sauvignon, Merlot, Pinot Noir, Cab Franc, Shiraz/Syrah, Chianti.
  • Dry white wines: Chardonnay, Pinot Grigio, Sauvignon Blanc.

NO Foods

You may NOT eat any of the following foods during the Two-Week Test.


  • All sugar products: Includes basically anything with honey, sugar, agave, fructose, crystals (e.g. beet crystals), cane, extract, or syrup in its ingredient list.
  • Sweets and desserts: Cake, cookies, ice cream, muffins, candy, gum, breath mints.
  • All non-caloric sweeteners (natural and non-natural): Includes stevia, xylitol, erythritol, aspartame, splenda, etc.
  • Many canned and prepared veggies: Read the labels to make sure they don’t contain hidden sugars!
  • Bread: Sliced bread or rolls of any kind (whole-grain, multi-grain, flaxseed, rye, gluten-free, etc).
  • Pasta: All types.
  • Crackers: Includes chips, rice cakes, and similar foods.
  • Packaged energy bars: And all packaged foods promoted as fuel for athletes.
  • Ketchup and other sauces: They often contain hidden sugars.
  • Corn: Bread, tortillas, etc.
  • Rice: Wild rice, brown rice, white rice, basmati rice, etc.
  • All wheat and wheat products: Whole wheat, farro, bulgur, khorasan, millet, etc.
  • Quinoa: Includes quinoa seeds and all products (e.g. quinoa pasta).
  •  Potatoes: Any kind (russet, red, blue, etc.)
  • Fruits and berries: Bananas, apples, pears, oranges, grapefruits grapes, blueberries, strawberries, cranberries grapefruit, watermelon, cantaloupe, honeydew.
  • Legumes: Beans, lentils, fava beans, peas, chickpeas, peanuts, etc.


  • Processed meats: Sausage, pastrami, salami, pepperoni, etc.
  • Smoked products: Jerky (beef, buffalo, etc), smoked fish.
  • Many canned and prepared meats: Read the labels to make sure they don’t contain hidden sugars!


  • Milk: Especially low-fat and non-fat milk.
  • Half-and-half.
  • Yogurt and kefir: All types, including full-fat yogurt.
  • Processed cheeses: Stay away from pre-sliced, single-serving, pre-shredded, high-value corporate branding, etc.


  • Avoid corn, safflower, or canola and other vegetable oils during the test and after.


  • Fruit Juice: Any type — orange, berry, watermelon, etc.
  • All soda: diet and non-diet soda.
  • All diet drinks: Diet shakes, etc.
  • “Enhanced” Beverages: Vitamin water, mineral water with “health” additives.
  • Sports drinks.
  • Sweet wines: liqueur, Champagne, rum, etc.

If it comes in a box, bag, jar or can, there’s a good chance it’s a no food for the Two-Week Test. Be sure to read the ingredients for all packaged foods, as some form of sugar or carbohydrate is typically added. Better yet, simply avoid all packaged and processed foods for two weeks!

Click here for some meal ideas to use during the Two-Week Test.

Now that you know which foods to eat, you can start the Two-Week Test!

Post Test Evaluation

What is the Post-Test?

The Post-Test is meant to determine if any of the carbohydrates you eliminated cause the return of any of the original signs or symptoms, including weight gain. At this stage, having just completed the test, your body and brain will be more sensitive to the slightest amounts of carbohydrates. Basically, you’ll become more intuitive to how your body responds to food.

Step 1: Re-evaluation of symptoms.

Re-evaluate your original list of complaints after the Two-Week Test:

  •      Is your energy better?
  •      Are you sleeping better?
  •      Are you feeling less depressed?
  •      Have you lost inches around your waist?

If you answered “yes” to any of those questions or you lost body fat, you probably have CI to some extent. People who have a high degree of CI may feel dramatically better than they did before the test, especially if there was a large weight loss.

Any fat loss during the test is not due to reduced calories, but rather to the increased fat-burning resulting from reduced insulin (many people eat more calories than usual during this two-week period). Although some of the change in weight may be due to water loss, a significant amount will be due to fat loss.

If you are on medication for high blood pressure, ask your health-care professional to check it several times during the test — and especially right after. Sometimes, blood pressure drops significantly and your medication may need to be adjusted or eliminated — something that  should only be done by your health-care professional. As insulin levels fall to normal, high blood pressure typically falls as well.

If nothing improved during the Two-Week test (and it was done exactly as described above), then you may not be carbohydrate intolerant. But if the test cleared up your signs and symptoms, the next step is to determine how many carbohydrates your body can tolerate without a relapse. This is done by adding a little bit of carbohydrates to your diet.

Step 2: Re-incorporating foods into the diet.

The best way to add foods is in the following order. Each day, add one serving of one food to your midday meal, starting with No. 1 and working your way down the list. You want to try only one of these foods per day, meaning that on day two, you do not include servings of food No. 1.

  1. Legumes
  2. Low-glycemic fruits (berries, grapefruit, prunes)
  3. Medium-glycemic fruits (apple, orange, pear, strawberries)
  4. Gluten-free grains (whole oats, brown rice)
  5. Grains with gluten, if not intolerant
  6. 1 teaspoon of organic honey with coffee or tea (excluding agave, or any other kind of sugary substance)

If you start seeing old signs and symptoms arise again, you know that the type of food or the quantity isn’t good for you.

Since insulin production is partly influenced by your previous meal, don’t add carbohydrates in back-to-back meals or snacks. During this period, make a note of any symptoms you had previously that were eliminated by the test. In particular, look for symptoms that develop immediately after eating, such as intestinal bloating, sleepiness or feelings of depression.

If any signs or symptoms that disappeared during or following the Two-Week Test have now returned, you’ve probably exceeded your carbohydrate limit. For example:

  •      You’re getting cravings again.
  •      You are gaining weight again.
  •      Your blood pressure rises significantly after it was reduced.

If any of these situations occur, reduce the carbohydrates by half. You can also experiment to see which particular foods cause symptoms and which don’t. Some people return to the Two Week Test and begin the process again.

A note on bread

Most bread, crackers, cereals and other grains are processed and should be completely avoided. Even those labeled “whole grain” or “100 percent whole wheat” are typically processed in some fashion. Read ingredient lists carefully. Use real-food whole grain products, if you can find them. These include sprouted breads, whole oats (which take 30 to 45 minutes to cook), and other dense products made with just ground wheat, rye, or other grains. If in doubt, avoid them.

Some people can tolerate simple carbohydrates, such as fresh fruits, plain yogurt and honey, but not complex carbohydrates such as sweet potato, whole grains, beans or other starches. (Some people with CI have difficulty digesting starches.) During the post-test period, it’s easy to determine whether an individual can’t tolerate any wheat products due to a sensitivity or even allergy or other response to gluten.

From time to time, you may feel the need to go through a Two-Week Test period again to check yourself, or to quickly get back on track after careless eating such as during the holidays, vacations or periods of stress.

Many people find the loss of grains in the diet leaves the digestive tract sluggish and a little constipated. After years of eating lots of carbohydrates, your intestine gets used to that type of bulk. If you become constipated during the Two-Week Test, or afterwards when a lower amount of carbohydrate in the diet is maintained, it could be due to a number of reasons:

  • Lack of Fiber. If you require a fiber supplement, be sure to use the ones that do not contain sugar, so read the labels. Psyllium is a high-fiber herb that is an effective promoter of intestinal function. Adding plain unsweetened psyllium to a glass of water, tomato juice, or healthy smoothie can keep your system running smoothly. Add one teaspoon a day for a few days to make sure it’s tolerated, then move towards one tablespoon a day.
  • Dehydration. If you don’t drink enough water, you could be predisposed to constipation. During the Two-Week Test, you’ll need more water — up to two to three quarts or more per day — which is a normal amount for a person of average weight.
  • Other Nutrients. Adequate intake of natural fats can also be helpful in preventing constipation. Vegetables, legumes such as lentils, and fruits are also great sources of fiber. So if you become constipated, it may simply be that you need to eat more vegetables and fruits.

Occasionally, some people get tired during or after the Two-Week Test. Most commonly it’s from not eating enough food, or not eating often enough. The most common problem is not eating breakfast. Most people should not go more than three to four hours without eating something healthy.

Maintaining Your Food Balance

Once you successfully finish the Two-Week Test, and add back the right amount of tolerable carbohydrate foods, you should have an excellent idea of your carbohydrate limits.

Now, you’re on your way to balancing your whole diet. During this process, take the time to learn which of the choices available in supermarkets, farmer’s markets, and elsewhere are truly healthy, and which should be avoided. While there’s nothing radical about the notion that refined carbohydrates are unhealthy, many radical diet plans make it seem like all carbohydrates are deadly. They’re not. It’s a lot more important to find your level of tolerance. Once you know it, eat only healthy carbohydrates — lentils, fresh fruit, unrefined grains (if tolerated), and organic honey as a sweetener.

 2 Week Test Download

Get background information on carbohydrate intolerance here.

About the Author Mark Fickler

Mark aka The Old Spartan and Over-50 Fitness Savior is a 61 year old coffee guzzling father of five wandering the outdoors around Albuquerque, New Mexico. Mark helps Men Over 50 get lean, healthy and strong so they can be cool dads and grand dads using his signature Spartan Method system.