Enda fördelen med GI-dieter

[KIRE]

Om man ska tro denna studie så är den enda fördelen vid dieter med lågt GI i viktminskningsyfte att man erhåller en lägre kolesterolnivå. Dieten blir inte effektivare i övrigt.

Har alltså alla förespråkare av högt/lågt GI vid olika tillfällen dragit lite förhastade slutsatser?

Hur stor roll spelar egentligen GI? Ska vi överväga att strunta helt i GI och bara bry oss om den kvalite(näringsmässigt) som de kolhydrater vi äter har?
Och sätta fokus på att äta rätt mängd kolhydrat istället.

Vad tror ni?

STudien följer nedan:

No difference in body weight decrease between a low-glycemic-index and a high-glycemic-index diet but reduced LDL cholesterol after 10-wk ad libitum intake of the low-glycemic-index diet.

Sloth B, Krog-Mikkelsen I, Flint A, Tetens I, Bjorck I, Vinoy S, Elmstahl H, Astrup A, Lang V, Raben A.

Department of Human Nutrition, Centre for Advanced Food Studies, The Royal Veterinary and Agricultural University, 30 Rolighedsvej, DK-1958 Frederiksberg C, Denmark. bsl@kvl.dk

BACKGROUND: The role of glycemic index (GI) in appetite and body-weight regulation is still not clear. OBJECTIVE: The objective of the study was to investigate the long-term effects of a low-fat, high-carbohydrate diet with either low glycemic index (LGI) or high glycemic index (HGI) on ad libitum energy intake, body weight, and composition, as well as on risk factors for type 2 diabetes and ischemic heart disease in overweight healthy subjects.

DESIGN: The study was a 10-wk parallel, randomized, intervention trial with 2 matched groups. The LGI or HGI test foods, given as replacements for the subjects' usual carbohydrate-rich foods, were equal in total energy, energy density, dietary fiber, and macronutrient composition. Subjects were 45 (LGI diet: n = 23; HGI diet: n = 22) healthy overweight [body mass index (in kg/m(2)): 27.6 +/- 0.2] women aged 20-40 y. RESULTS: Energy intake, mean (+/- SEM) body weight (LGI diet: -1.9 +/- 0.5 kg; HGI diet: -1.3 +/- 0.3 kg), and fat mass (LGI diet: -1.0 +/- 0.4 kg; HGI diet: -0.4 +/- 0.3 kg) decreased over time, but the differences between groups were not significant. No significant differences were observed between groups in fasting serum insulin, homeostasis model assessment for relative insulin resistance, homeostasis model assessment for beta cell function, triacylglycerol, nonesterified fatty acids, or HDL cholesterol. However, a 10% decrease in LDL cholesterol (P < 0.05) and a tendency to a larger decrease in total cholesterol (P = 0.06) were observed with consumption of the LGI diet as compared with the HGI diet. CONCLUSIONS: This study does not support the contention that low-fat LGI diets are more beneficial than HGI diets with regard to appetite or body-weight regulation as evaluated over 10 wk. However, it confirms previous findings of a beneficial effect of LGI diets on risk factors for ischemic heart disease.

[King Grub]

Ingen har påstått att GI har samma innebörd för en idrottsman med superb insulinkänslighet som för en soffpotatis.

Att det är ett effektivt hjälpmedel råder det inte några som helst tvivel om, och där givetvis som ett sådant konceptet skall användas, inte som det "be-all, end-all" det alltför ofta framställts som.

"The authors investigated the association of body mass index (weight (kg)/height (m)(2)) with dietary intake of carbohydrates and with measures of the induced glycemic response, using data from an observational study of 572 healthy adults in central Massachusetts. Anthropometric measurements, 7-day dietary recalls, and physical activity recalls were collected quarterly from each subject throughout a 1-year study period. Data were collected between 1994 and 1998. Longitudinal analyses were conducted, and results were adjusted for other factors related to body habitus. Average body mass index was 27.4 kg/m(2) (standard deviation, 5.5), while the average percentage of calories from carbohydrates was 44.9 (standard deviation, 9.6). Mean daily dietary glycemic index was 81.7 (standard deviation, 5.5), and glycemic load was 197.8 (standard deviation, 105.2). Body mass index was found to be positively associated with glycemic index, a measure of the glycemic response associated with ingesting different types of carbohydrates, but not with daily carbohydrate intake, percentage of calories from carbohydrates, or glycemic load."

Am J Epidemiol. 2005 Feb 15;161(4):359-67.

"Resting energy expenditure decreased less with the low–glycemic load diet than with the low-fat diet, expressed in absolute terms (mean [SE], 96 [24] vs 176 [27] kcal/d; P = .04) or as a proportion (5.9% [1.5%] vs 10.6% [1.7%]; P = .05). Participants receiving the low–glycemic load diet reported less hunger than those receiving the low-fat diet (P = .04). Insulin resistance (P = .01), serum triglycerides (P = .01), C-reactive protein (P = .03), and blood pressure (P = .07 for both systolic and diastolic) improved more with the low–glycemic load diet."

JAMA. 2004;292:2482-2490.

"Alternative approaches include low-glycemic index and high protein diets. Both effectively reduce the glycemic load of the diet and early studies suggest they may be effective in increasing satiety, reducing ad libitum energy intake and may improve fat oxidation by reducing insulin demand. Both approaches can be used within the context of a reduced-fat diet, with evidence emerging to suggest this may improve weight and body composition outcomes."

Clin Dermatol. 2004 Jul-Aug;22(4):310-4.

I sammanhanget är det av betydelse att styrke- och sprintatleter är mer insulinresistenta än uthållighetsatleter (även om majoriteten här förhoppningsvis implementerar båda träningsformerna i sitt upplägg. Även om genetik spelar en signifikant roll, så går det säkert att påverka med träningsupplägg.

"A previous study has shown that former elite power athletes exhibited significantly greater relative risk in diabetes than that of former elite endurance athletes. It is unknown whether insulin sensitivity in elite young healthy power athletes is lower than that in elite young endurance athletes. This study includes two parts, part I and part II. In the part I of this study, an oral glucose tolerance test was performed in all of the elite juvenile track athlete subjects, specializing either in short-distance racing (jSD, N = 13, aged 12.5 +/- 0.37 years) or in long-distance racing (jLD, N = 13, aged 12.6 +/- 0.42 years). In the part II of this study, we recruited elite adult swimmers and divided them into two groups according to their specialty in swimming race distance: long-distance (aLD, N = 10, age 20.3 +/- 1.32) and short-distance groups (aSD, N = 10, age 20.2 +/- 1.31). Insulin sensitivity was significantly lower in the jSD group than that in the jLD group, as indicated by the area under the curves of insulin and glucose following a 75-g oral glucose load. Fasting plasma LDL-C and total cholesterol levels in the jSD group were significantly greater than those in the jLD group. The result of the part II of this study, similar to the result of the part I, shows that insulin sensitivity in aSD swimmers was significantly lower than that in aLD swimmers. LDL-C, total cholesterol, and triglyceride levels were also found higher in aSD swimmers than in those of aLD swimmers. These new findings implicate that the genetic makeup associated with exceptional power or endurance performance of elite athletes could also reflect on their metabolic characteristics; elite power athletes appear to be more insulin resistant than elite endurance athletes."

Prev Med. 2005 May;40(5):564-9, Characteristics of glycemic control in elite power and endurance athletes.

[KIRE]

Ursprungligen postat av King Grub

Ingen har påstått att GI har samma innebörd för en idrottsman med superb insulinkänslighet som för en soffpotatis.

Har ingen gjort det? Det var kanske en liten överdrift
snarare så att ett extremt litet fåtal bland dagens
träningsutövare inte är insnöade på GI. Det enda man hör
dagarna i ända är GI hit och GI dit(jobbar som kostrådgivare på gymmet ibland efter skolan). När man pratar med folk
om kost så får man i 9 av 10 fall avsätta första halvtimmen till
att försöka övertyga dom om att GI faktiskt inte är det enda man
ska fokusera sin kost på. Därefter får man tillbringa nästa halvtimme
med att förklara att man inte måste ta en proteindrink innan
morgonpromenaden. Sen blir det en halvtimme till med att försöka
förklara varför högintensiv träning är bättre än promenader osv osv..
Därefter kan man behandla det man egentligen skulle tala om.
Tack paulun för det..