Glycemic

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The glycemic response to a food or meal is the effect that food or meal has on blood sugar (glucose) levels after consumption. [1] It is normal for blood glucose and insulin levels to rise after eating and then return again to fasting levels over a short period of time. This is particularly so after consumption of meals rich in certain carbohydrates. Glycemic management refers to the selection of foods to manage your blood sugar levels.

Several tools have been developed to help quantify and communicate the effect of food on glycemic response. These include glycemic index (GI), glycemic load (GL) and glycemic glucose equivalents (GGE). A comparative glycemic response can also be determined, which compares the impact on blood glucose of one food to another based upon their total carbohydrate or total quantity.

In 1981, the idea of classifying carbohydrates according to their Glycemic Index was first published. Since then, many studies have been undertaken to determine the impact of altering the blood glucose-raising potential (glycemic challenge) of the diet on a wide range of short- and long-term health outcomes. However, evaluating the impact of a single dietary change on health is notoriously complex, and opinions on the relevance of GI, GL and GGE have been divided. There are many different ways of lowering glycemic response, GI or GL, not all of which have the same effects on health. ILSI Europe published a monograph in November 2011 titled "Food, Glycaemic Response and Health", which concluded that "it is becoming evident that modifying the glycemic response of the diet should not be seen as a stand-alone strategy but rather as an element of an overall balanced diet and lifestyle".

A low glycemic food will release glucose more slowly and steadily, which leads to lower postprandial (after meal) blood glucose readings. A high glycemic food causes a more rapid rise in blood glucose levels after meals. High glycemic foods are ideal for energy recovery after exercise or for a person experiencing hypoglycemia.

The glycemic effect of foods depends on a number of factors such as the type of starch (amylose versus amylopectin), physical entrapment of the starch molecules within the food, fat and protein content of the food and organic acids or their salts in the meal — adding vinegar, for example, will lower the glycemic response. The presence of fat or soluble dietary fiber can slow the gastric emptying rate, thus lowering the glycemic response. In general, foods with higher amounts of fiber and/or resistant starch have a lower glycemic response.

While adding fat or protein will lower the glycemic response to a meal, the relative differences remain. That is, with or without additions, there is still a higher blood glucose curve after a high glycemic white bread than after a low gycemic bread such as pumpernickel.

Unrefined wild plant foods like those available to contemporary foragers typically exhibit low glycemic indices. [2]

Related Research Articles

Carbohydrate Organic compound that consists only of carbon, hydrogen, and oxygen

A carbohydrate is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula Cm(H2O)n (where m may or may not be different from n). However, not all carbohydrates conform to this precise stoichiometric definition (e.g., uronic acids, deoxy-sugars such as fucose), nor are all chemicals that do conform to this definition automatically classified as carbohydrates (e.g. formaldehyde and acetic acid).

Dieting is the practice of eating food in a regulated way to decrease, maintain, or increase body weight, or to prevent and treat diseases such as diabetes and obesity. As weight loss depends on calorie intake, different kinds of calorie-reduced diets, such as those emphasising particular macronutrients, have been shown to be no more effective than one another. As weight regain is common, diet success is best predicted by long-term adherence. Regardless, the outcome of a diet can vary widely depending on the individual.

Polysaccharide Long carbohydrate polymers comprising starch, glycogen, cellulose, and chitin

Polysaccharides, or polycarbohydrates, are the most abundant carbohydrate found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with water (hydrolysis) using amylase enzymes as catalyst, which produces constituent sugars. They range in structure from linear to highly branched. Examples include storage polysaccharides such as starch, glycogen and galactogen and structural polysaccharides such as cellulose and chitin.

Dietary fiber Portion of plant-derived food that cannot be completely digested

Dietary fiber or roughage is the portion of plant-derived food that cannot be completely broken down by human digestive enzymes. Dietary fibers are diverse in chemical composition, and can be grouped generally by their solubility, viscosity, and fermentability, which affect how fibers are processed in the body. Dietary fiber has two main components: soluble fiber and insoluble fiber, which are components of plant foods, such as legumes, whole grains and cereals, vegetables, fruits, and nuts or seeds. A diet high in regular fiber consumption is generally associated with supporting health and lowering the risk of several diseases.

Glycemic index Number assigned to food

The glycemic index is a number from 0 to 100 assigned to a food, with pure glucose arbitrarily given the value of 100, which represents the relative rise in the blood glucose level two hours after consuming that food. The GI of a specific food depends primarily on the quantity and type of carbohydrate it contains, but is also affected by the amount of entrapment of the carbohydrate molecules within the food, the fat and protein content of the food, the amount of organic acids in the food, and whether it is cooked and, if so, how it is cooked. GI tables, which list many types of foods and their GIs, are available. A food is considered to have a low GI if it is 55 or less; high GI if 70 or more; and mid-range GI if 56 to 69.

Low-carbohydrate diet Diets restricting carbohydrate consumption

Low-carbohydrate diets restrict carbohydrate consumption relative to the average diet. Foods high in carbohydrates are limited, and replaced with foods containing a higher percentage of fat and protein, as well as low carbohydrate foods.

Ketogenic diet High-fat dietary therapy for epilepsy

The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet that in medicine is used mainly to treat hard-to-control (refractory) epilepsy in children. The diet forces the body to burn fats rather than carbohydrates.

The glycemic load (GL) of food is a number that estimates how much the food will raise a person's blood glucose level after eating it. One unit of glycemic load approximates the effect of eating one gram of glucose. Glycemic load accounts for how much carbohydrate is in the food and how much each gram of carbohydrate in the food raises blood glucose levels. Glycemic load is based on the glycemic index (GI), and is calculated by multiplying the grams of available carbohydrate in the food by the food's glycemic index, and then dividing by 100.

Tagatose Chemical compound

Tagatose is a hexose monosaccharide. It is found in small quantities in a variety of foods, and has attracted attention as an artificial sweetener. It is often found in dairy products, because it is formed when milk is heated. It is similar in texture and appearance to sucrose :215 and is 92% as sweet,:198 but with only 38% of the calories.:209 Tagatose is generally recognized as safe by the Food and Agriculture Organization and the World Health Organization, and has been since 2001. Since it is metabolized differently from sucrose, tagatose has a minimal effect on blood glucose and insulin levels. Tagatose is also approved as a tooth-friendly ingredient for dental products. Consumption of more than about 30 grams of tagatose in a dose can cause gastric disturbance, as it is mostly processed in the large intestine.:214

Isomaltulose Chemical compound

Isomaltulose is a disaccharide carbohydrate composed of glucose and fructose. The glucose and fructose are linked by an alpha-1,6-glycosidic bond. Isomaltulose is present in honey and sugarcane extracts. It tastes similar to sucrose with half the sweetness. Isomaltulose, also known by the trade name Palatinose, is manufactured by enzymatic rearrangement (isomerization) of sucrose from beet sugar. The enzyme and its source were discovered in Germany in 1950, and since then its physiological role and physical properties have been studied extensively. Isomaltulose has been used as an alternative to sugar in foods in Japan since 1985, in the EU since 2005, in the US since 2006, and in Australia and New Zealand since 2007, besides other countries worldwide. Analytical methods for characterization and assay of commercial isomaltulose are laid down, for example, in the Food Chemicals Codex. Its physical properties closely resemble those of sucrose, making it easy to use in existing recipes and processes.

The Montignac diet is a high-protein low-carbohydrate fad diet that was popular in the 1990s, mainly in Europe. It was invented by Frenchman Michel Montignac (1944–2010), an international executive for the pharmaceutical industry, who, like his father, was overweight in his youth. His method is aimed at people wishing to lose weight efficiently and lastingly, reduce risks of heart failure, and prevent diabetes.

The insulin index of food represents how much it elevates the concentration of insulin in the blood during the two-hour period after the food is ingested. The index is similar to the glycemic index (GI) and glycemic load (GL), but rather than relying on blood glucose levels, the Insulin Index is based upon blood insulin levels. The Insulin Index represents a comparison of food portions with equal overall caloric content, while GI represents a comparison of portions with equal digestible carbohydrate content and the GL represents portions of a typical serving size for various foods. The Insulin Index can be more useful than either the glycemic index or the glycemic load because certain foods cause an insulin response despite there being no carbohydrates present, and some foods cause a disproportionate insulin response relative to their carbohydrate load.

A diabetic diet is a diet that is used by people with diabetes mellitus or high blood sugar to minimize symptoms and dangerous complications of long-term elevations in blood sugar.

Nutritional rating systems are used to communicate the nutritional value of food in a more-simplified manner, with a ranking, than nutrition facts labels. A system may be targeted at a specific audience. Rating systems have been developed by governments, non-profit organizations, private institutions, and companies. Common methods include point systems to rank foods based on general nutritional value or ratings for specific food attributes, such as cholesterol content. Graphics and symbols may be used to communicate the nutritional values to the target audience.

Dietary Reference Values (DRV) is the name of the nutritional requirements systems used by the United Kingdom Department of Health and the European Union's European Food Safety Authority.

The South Beach Diet is a popular fad diet developed by Arthur Agatston and promoted in a best-selling 2003 book. It emphasizes eating food with a low glycemic index, and categorizes carbohydrates and fats as "good" or "bad". Like other fad diets, it may have elements which are generally recognized as sensible, but it promises benefits not backed by supporting evidence or sound science.

Weight management Techniques for maintaining body weight

Weight management includes the techniques and physiological processes that contribute to a person's ability to attain and maintain a certain weight. Most weight management techniques encompass long-term lifestyle strategies that promote healthy eating and daily physical activity. Moreover, weight management involves developing meaningful ways to track weight over time and to identify ideal body weights for different individuals.

Prevention of type 2 diabetes can be achieved with both lifestyle changes and use of medication. The American Diabetes Association categorizes prediabetes as a high-risk group that has glycemic levels higher than normal but does not meet criteria for diabetes. Without intervention people with prediabetes progress to type 2 diabetes with a 5% to 10% rate. Diabetes prevention is achieved through weight loss and increased physical activity, which can reduce the risk of diabetes by 50% to 60%.

Isomaltooligosaccharide (IMO) is a mixture of short-chain carbohydrates which has a digestion-resistant property. IMO is found naturally in some foods, as well as being manufactured commercially. The raw material used for manufacturing IMO is starch, which is enzymatically converted into a mixture of isomaltooligosaccharides.

Oat beta-glucan

Oat β-glucans are water-soluble β-glucans derived from the endosperm of oat kernels known for their dietary contribution as components of soluble fiber. Due to their property to lower serum total cholesterol and low-density lipoprotein cholesterol, and potentially reduce the risk of cardiovascular diseases, oat β-glucans have been assigned a qualified health claim by the European Food Safety Authority and the US Food and Drug Administration.

References

  1. Sadler M. Food, Glycaemic Response and Health. ILSI Europe Concise Monograph Series 2011:1-30. Available from ILSI Europe.
  2. Foster-Powell K; Holt SH; Brand-Miller J (1 July 2002). "International table of glycemic index and glycemic load values: 2002". The American Journal of Clinical Nutrition . 76 (1): 5–56. doi: 10.1093/ajcn/76.1.5 . PMID   12081815.