Learning to read labels is an absolute requirement in buying foods for an HFI diet. Sugars are an especially difficult aspect to learn since they occur in so many different forms, especially in processed foods. If you do not recognize an ingredient on a food package, assume that it is prohibited until you know for sure what it is. Sugars and Sugar Substitutes, Fructose, Glucose, and Dextrose are examples of monosaccrides (simple sugars), which are sugar molecules that cannot be broken down further and remain a sugar. Polysaccrides (complex sugars) such as sucrose and lactose are larger molecules that are combinations of two or more sugar molecules. Honey is almost pure fructose, as are grape syrup, and other fruit juice sweeteners. Agave syrup contains high levels of fructose. Sucrose (table sugar) is derived from either sugar cane (or evaporated cane), sugar beets, brown rice, or dates and is a polysaccride consisting of glucose and fructose. Brown sugar is sucrose coated with molasses. Maple syrup or maple sugar are also mostly sucrose. Corn syrup and corn syrup solids are polysaccrides consisting of glucose and maltose. Although this combination should be tolerated, fructose is often added so the purity of the corn syrup has to be high to be tolerated. Not recommended. High Fructose Corn Syrup is being used extensively in the US because it is cheap to manufacture from corn syrup (which is mostly glucose). An industrial process converts the corn syrup glucose using an enzyme into a mixture of glucose and fructose in roughly equal proportions (about 55% fructose). The reason for doing this is that fructose is much sweeter tasting that the original glucose and the combination is a cheap sucrose replacement. Tariffs, quotas and subsidies on sugar imported to the US make the economics of HFCS even more attractive. Currently the US intake of HFCS matches the intake of table sugar in dry weight (about 60 lbs of each per year per person). As an exercise, the next time you go to a grocery store, pick up packaged foods and read the labels. You will be amazed at how many foods contain HFCS. Not only does the HFCS industry have a powerful political lobby to pass favorable laws, they must also have an extremely effective sales force for so many food manufacturers to incorporate it into products where its use makes no obvious sense. Chicory is used to make fructose and is not tolerated. Sorbitol is a sugar alcohol which the body converts into fructose. Dextrose is a simple sugar that is well tolerated. Glucose is a simple sugar that the body uses for energy. Maltitol is a sugar alcohol that may be tolerated depending on purity. Aspartame is an artificial sweetener that is tolerated, although some individuals report headaches. It is used in Equal, Nutrasweet, and Nutratase. Acesulfame-K is another artificial sweetener that is tolerated although its safety has recently been questioned. Saccharin is an artificial sweetener with questionable safety. It is no longer approved for use in Canada due to cancer concerns. Splenda or sucralose is a common sugar substitute. It is a chemically modified sucrose molecule that can be well tolerated depending on purity, although it can produce bowel issues if too much is consumed at once. Once you have memorized all of these sugars and know which to avoid and which are (or may be) safe to consume, you still have to master which foods contain which sugars. For example, bacon and ham can often contain maple sugar as an additive to cure and flavor the meat. Maple sugar contains sucrose which in turn breaks down to fructose.
Foods and Fructose
Fructose is generally contained in fruits, but actually occurs in a wide variety of foods. Not only are all fruits prohibited, you must also include those less obvious fruits such as melons, tomatoes, and coconuts on the HFI prohibited list. Many vegetables such as onions, corn, and peas contain unacceptably high levels of fructose and should be avoided. Thus, products containing onions or corn are excluded, including those that contain onion powder or corn flour. Wheat and all products containing wheat should be avoided. This is an extremely difficult requirement because of the number of products that contain wheat. Many products are labeled in a way that makes it less than obvious that wheat is included. For example, pasta packages may show semolina on the ingredients list. You must know that semolina is a type of wheat. Even foods labeled safe for Celiac Disease sufferers (who are intolerant of wheat gluten) are not usually safe for HFI use. Many of the grain flours which substitute for wheat may not have wheat gluten but do have significant fructose content. For example, brown rice and soy flours are not HFI safe. We have not found a satisfactory commercial bread substitute to date, but a combination of white rice flour and tapioca flour seems to make good bread that can be tolerated. Rice pasta is well tolerated, although you should avoid pasta made specifically with brown rice. Nuts and seeds are not generally tolerated as they all contain significant quantities of fructose. Soy products contain fructose and should be avoided. Most meats are well tolerated if not processed (ground and combined with other ingredients). Ham and bacon are not typically safe since they are sugar cured, although with some effort you may be able to locate a ham that uses only dextrose in the curing. Bacon is usually even more difficult although we have found that some stores carry salt pork sides that are essentially uncured, un-smoked bacon. Dairy products are generally well tolerated although you must read labels. Yogurts typically have sugars added.