The American Diabetes Association nutrition principles and recommendations (1,2) do acknowledge that a number of factors influence the glycemic response to food, including the amount of carbohydrate, type of sugar, nature of the starch, cooking and food processing, particle size, food structure, and other food components (fat and natural substances that slow digestion) as well as the fasting and preprandial glucose concentrations, severity of glucose intolerance, and the second meal or lente effect (1). The question that the task force asked was, is there evidence that chronic consumption of low-glycemic index foods will contribute to improved glycemia in people with diabetes? The concern being that if another layer of complexity (glycemic index) is to be added to food/meal planning guidelines, there should be clear evidence of benefit.

To answer this question, all studies comparing low- and high-glycemic index diets for 2 weeks or longer were reviewed. As can be seen from Tables 1 and 2, the number of studies is limited. Moreover, the design and implementation of several of these studies is subject to criticism, and in none of the studies was the effect of the diets on postprandial glucose concentrations reported.

Clearly, longer and larger studies are needed to evaluate the utility of glycemic indexing. Until such studies are available, use of low-glycemic index diets is not, in our judgment, evidenced based. Recommendations by other organizations do not change this. We do acknowledge that some individuals might benefit from low-glycemic index diets. However, a decision to use such a diet should be an individual one made in consultation with a nutrition counselor.

Table 1—

Type 1 diabetes: low-glycemic index diets compared with high-glycemic index diets in studies lasting 2 weeks or longer (5 studies, 48 subjects)

EndpointLow GI significantly better than high GINo significant difference
HbA1c 4 [n = 40] (3, 4, 6, 7
Fructosamine 3 [n = 27] (3, 5, 61 [n = 9] (7
Fasting plasma glucose 3 [n = 27] (3, 5, 6
EndpointLow GI significantly better than high GINo significant difference
HbA1c 4 [n = 40] (3, 4, 6, 7
Fructosamine 3 [n = 27] (3, 5, 61 [n = 9] (7
Fasting plasma glucose 3 [n = 27] (3, 5, 6

Data are n. Numbers in parenthesis refer to the reference list. GI, glycemic index.

Table 2—

Type 2 diabetes: low-glycemic index diets compared with high-glycemic index diets in studies lasting 2 weeks or longer (10 studies, 174 subjects)

EndpointLow GI significantly better than high GINo significant difference
HbA1c 1 [n = 16] (95 [n = 92] (4,6,8,13,15
Fructosamine 3 [n = 41] (10, 11, 143 [n = 54] (8,12,13
Fasting plasma glucose 9 [n = 162] (6,815
EndpointLow GI significantly better than high GINo significant difference
HbA1c 1 [n = 16] (95 [n = 92] (4,6,8,13,15
Fructosamine 3 [n = 41] (10, 11, 143 [n = 54] (8,12,13
Fasting plasma glucose 9 [n = 162] (6,815

Data are n. Numbers in parenthesis refer to the reference list. GI, glycemic index.

1
Franz MJ, Bantle JP, Beebe CA, Brunzell JD, Chiasson J-L, Garg A, Holzmeister LA, Hoogwerf B, Mayer-Davis E, Mooradian A, Purnell JQ, Wheeler M: Evidence-based nutrition principles and recommendations for the treatment and prevention of diabetes and related complications (Technical Review).
Diabetes Care
25
:
148
–198,
2002
2
American Diabetes Association: Evidence-based nutrition principles and recommendations for the treatment and prevention of diabetes and related complications (Position Statement).
Diabetes Care
25
:
202
–212,
2002
3
Collier GR, Giudici S, Kalmusky J, Wolever TMS, Helman G, Wesson V, Ehrlich RM, Jenkins DJA: Low glycaemic index starchy foods improve glucose control and lower serum cholesterol in diabetic children.
Diab Nutr Metab
1
:
11
–19,
1988
4
Calle-Pascual AL, Gomez V, Leon E, Bordiu E: Foods with a low glycemic index do not improve glycemic control of both type 1 and type 2 diabetic patients after one month of therapy.
Diabet Metab
14
:
629
–633,
1988
5
Fontvieille AM, Acosta M, Rizkalla SW, Bornet F, David P, Letanoux M, Tchobroutsky G, Slama G: A moderate switch from high to low glycaemic-index foods for 3 weeks improves the metabolic control of type I (IDDM) diabetic subjects.
Diab Nutr Metab
1
:
139
–143,
1988
6
Fontvieille AM, Rizkalla SW, Penfornis A, Acosta M, Bornet FR, Slama G: The use of low glycaemic index foods improves metabolic control of diabetic patients over five weeks.
Diabet Med
9
:
444
–450,
1992
7
Lafrance L, Rabasa-Lhoret R, Poisson D, Ducros F, Chiasson J-L: The effects of different glycaemic index foods and dietary fibre intake on glycaemic control in type 1 diabetic patients on intensive insulin therapy.
Diabet Med
15
:
972
–978,
1998
8
Jenkins DJA, Wolever TMS, Buckley G, Lam KY, Giudici S, Kalmusky J, Jenkins AL, Patten RL, Bird J, Wong GS, Josse RG: Low-glycemic index starchy foods in the diabetic diet.
Am J Clin Nutr
48
:
248
–254,
1988
9
Brand JC, Colagiuri S, Crossman S, Allen A, Roberts DCK, Truswell AS: Low glycemic index foods improve long-term glycemic control in NIDDM.
Diabetes Care
14
:
95
–101,
1991
10
Wolever TMS, Jenkins DJA, Vuksan V, Jenkins AL, Wong GS, Josse RG: Beneficial effect of low-glycemic index diet in type 2 diabetes.
Diabet Med
9
:
451
–458,
1992
11
Wolever TMS, Jenkins DJA, Vuksan V, Jenkins AL, Buckley GC, Wong GS, Josse RG: Beneficial effects of low-glycemic index diets in overweight NIDDM.
Diabetes Care
15
:
562
–564,
1992
12
Frost G, Keogh B, Smith D, Akinsanya K, Leeds A: The effect of low-glycemic carbohydrate on insulin and glucose responses in vivo and in vitro in patients with coronary heart disease.
Metabolism
45
:
669
–672,
1996
13
Luscombe ND, Noakes M, Clifton PM: Diets high and low in glycemic index versus high monounsaturated fat diets: effects on glucose and lipid metabolism in NIDDM.
Eur J Clin Nutr
53
:
473
–478,
1999
14
Jarvi A, Karlstrom B, Granfeldt Y, Bjorck I, Asp NG, Vessby B: Improved glycemic control and lipid profile and normalized fibrinolytic activity on a low glycemic index diet in type 2 diabetic patients.
Diabetes Care
22
:
10
–18,
1999
15
Heilbronn LK, Noakes M, Clifton PM: The effect of high- and low-glycemic index energy restricted diets on plasma lipid and glucose profiles in type 2 diabetic subjects with varying glycemic control.
J Am Coll Nutr
21
:
120
–127,
2002

Address correspondence to Marion J. Franz, 6635 Limerick Dr., Minneapolis, MN 55439. E-mail: marionfranz@aol.com.