The Glyx diet is primarily intended to eat foods with a low glycemic index . The amounts of fats , proteins and carbohydrates as well as the physiological calorific value of the food are of secondary importance. The name Glyx Diet comes from the ecotrophologist Marion Grillparzer and the Graefe und Unzer Verlag, who introduced the term Glyx in 1999 as a short form for "glycemic index". The diet is related to the Montignac method and the Logi method . Their representatives recommend them for weight loss , but also as permanent nutrition. The method involves more than just restricting consumption of foods high in glyx. It is designed as a full-fledged diet that places value on fiber, essential fatty acids, sufficient protein, vitamins and sufficient fluid intake, among other things. The Glyx diet according to Marion Grillparzer takes into account not only the GI values of a food but also the amount and type of fat it contains. The focus of the diet is on the regular consumption of meat and fish as well as high-quality fats. At the same time, sugary foods are largely avoided. Exercise and relaxation are also recommended.
The Glycemic Index (Glyx, GI) describes the blood sugar reaction after eating and thus indirectly also the insulin reaction of the body. It is defined as the relative area under the two-hour blood sugar curve after ingesting 50 grams of carbohydrates. The GI is how quickly a food containing carbohydrates is digested and released into the blood as sugar. The GI of glucose was set at 100 and is considered to be the highest GI value. All other foods are related to this reference value in terms of their effect on blood sugar. The glycemic index was originally introduced by medical professionals who dealt with diet for diabetes mellitus .
For the diet, a distinction is made between “good” and “bad” carbohydrates. High glyx carbohydrate foods such as B. Glucose, lead to a rapid increase in blood sugar. The body secretes a lot of insulin to break down the sugar. The steeper the rise in blood sugar, the more violent the insulin reaction and the faster the blood sugar level falls again, so that you get hungry again faster, according to the theory.
Low glyx foods cause blood sugar levels to rise more slowly and insulin spikes are absent. When the insulin level is high, ingested fat is not broken down, but stored by the body. A constantly high level of insulin supposedly promotes the development of diabetes and arteriosclerosis . However, this is scientifically controversial.
Some studies have shown positive effects on blood lipid levels and the risk of heart attack in overweight people who prefer to eat foods with low glyx, especially when the amount of carbohydrates ingested is reduced.
The glyx of grape sugar (glucose) is set to a value of 100. Some tables also relate the Glyx value of 100 to the intake of 50 g of carbohydrates from white bread. According to the glucose standard, white bread has a glyx of 70, so the conversion factor between the two standards is 1.4.
100 is the highest GI value. A value below 55 is considered to be low. Pure dairy products, many types of fruit and vegetables , pasta (whether whole grains or not) have a low glyx . The mean GI is 55 to 70, including whole grain bread, apple juice, or normal sugar. For example, polished rice , white bread and mashed potatoes have a high glyx .
Since the Glyx alone can lead to strange nutritional recommendations - ice cream, for example, has a lower GI than potatoes - the representatives of this and similar diets also use the glycemic load as a criterion .
Evaluation and criticism
According to the German Nutrition Society in its updated statement from 2013, the results of the KH guidelines do not secure the role of the glycemic index for the prevention of diet-related diseases with a high level of evidence. According to the KH guidelines of the DGE, one possible evidence is between a high GI and an increased risk of obesity (in women), type 2 diabetes mellitus, coronary heart disease (in women) and malignant tumors in the colorectum. With likely evidence, total cholesterol levels increase with a high GI diet. Considering the GI of foods rich in carbohydrates can be seen as a guide to high quality foods.
The April 2018 edition of the DGE's monthly specialist information service "DGE-Info" deals with a. with the Glyx diet. It becomes clear that the study situation regarding the effect of the Glyx diet on health is inconsistent. “While some studies did not find a positive effect of GI / GL on various parameters of the metabolism, other studies came to the result that the glucose and insulin metabolism can be positively influenced by a low GI / GL. A diet with a low GI / GL seems to have a positive effect on the metabolism (and in particular the reduced release of insulin) especially in the presence of type 2 diabetes or impaired glucose tolerance. To what extent the Glyx diet affects healthy people or with existing diseases such as high blood pressure, cardiovascular diseases or lipid metabolism disorders cannot be clearly answered at the moment. "
The DGE positively emphasizes that in the Glyx diet "(added) sugar, soft drinks, beer, nutritionally unfavorable fats and fast food are dispensed with and the focus is on less processed foods."
"The claim of the Glyx and LOGI supporters that the intake of carbohydrates with a high GI would inevitably lead to an 'excessive' release of insulin, which would lead to a drop in the blood sugar level below the starting level or even to hypoglycemia and thus inevitably to cravings, is not durable and lacks any physiological basis. "
If only the GI value is taken into account, the energy absorbed through food intake is neglected (see: Energy balance of nutrition ). However, those who consume more energy than the body consumes gain weight , regardless of the glyx . Fat does not contain carbohydrates and therefore has a low GI but a very high physiological calorific value. For example, a slice of bread with butter and cheese has a lower GI than a dry slice of bread. Most foods are not eaten in isolation, but rather with others. However, the individual GI values cannot simply be added, this leads to incorrect results. In addition, the body's glycemic response to the same food can vary significantly in the same person, even within a day.
A five-year study with 1255 people, which was published in the British Journal of Nutrition in 2006 , came to the conclusion that there was no significant relationship between the glycemic index and blood sugar level. Study leader Elizabeth Mayer-Davis concluded: "The glycemic index is neither helpful for scientists nor for consumers in developing a healthy diet".
In a statement by the German Institute for Nutrition Research from 2007 it says: “The causality of the associations between glycemic load and disease risk has so far not been secured by appropriate intervention studies. The data on the influence of the glycemic index on body weight development are still inconsistent and also controversial; It has not yet been shown that a reduction in the glycemic load (by modifying or reducing the carbohydrate content of the diet) is clearly and sustainably superior to other dietary interventions (e.g. reducing the fat content). "
- Marion Grillparzer: The new Glyx Diet - Lose weight with a feeling of happiness . Newly revised edition. Gräfe and Unzer, 2009, ISBN 978-3-8338-1504-1
- Marion Grillparzer: The successful Simple Glyx diet . Gräfe and Unzer, 2015, ISBN 978-3833844133
- Michael Gusko: Ingredient branding as the ideal way to differentiate between B2C and B2B . In: Successful brand differentiation . Gabler, 2010, ISBN 978-3-8349-1722-5 , pp. 159 , doi : 10.1007 / 978-3-8349-8575-0_7 .
- Marion Grillparzer: GLYX diet . 2003, ISBN 3-7742-5785-X
- Marion Grillparzer: The successful diet Simple Glyx . Gräfe and Unzer, 2015, ISBN 978-3833844133
- K. Moosburger, T. Markmann: The glycemic index What is it about the "GLYX" diet? de.fitness.com, July 26, 2006. Originally from the now deleted page at the Medical University of Innsbruck: On the meaning of the Glyx
- Glycemic Index and Glycemic Load . (PDF; 91 kB) DGE
- Statement of the German Institute for Nutritional Research. ( Memento of September 27, 2007 in the Internet Archive ) (PDF) 2004