Diet Therapy
1. Diet Therapy in General
Diet therapy is the cornerstone of therapy for all patients with diabetes. Practicing an appropriate diet
improves glycemic control.1,2 (grade A)
2. Individualized Diet Therapy
Individualized diet therapy according to the lifestyle of each patient is essential for successful
introduction and continuation of the recommended diet therapy and requires, first and foremost, that
each patient be interviewed adequately about his/her dietary habits, such as food preferences and diet
timetables as well as his/her physical activity level. (grade A; consensus)
○ The elderly are often associated with disturbance of taste, smell, and mastication, reduced secretion of
saliva and gastric acid, and impaired renal and hepatic function, which leads to malnutrition and
sarcopenia. Therefore, it is required that diet therapy for the elderly be so formulated as to avoid the risk
of malnutrition.
3. Diet Instructions by Registered Dietitians
In clinical practice, diet instructions involving a registered dietitian are useful for glycemic control.3
(grade B)
The Food Exchange Lists, edited by the Japan Diabetes Society, is commonly used for diet instructions.
However, if it is difficult for patients to understand the Food Exchange Lists, actual food products or food
models may be used to give instructions. (grade B; consensus)
4. Determination of the Amount of Energy Intake
● The amount of energy intake is to be determined by a physician, with consideration given to his/her
glucose levels, blood pressure, serum lipid levels, height, body weight, age, sex, complications, and energy
expenditure (physical activity), as well as the amount of prior food intake. It must be also determined
individually to meet disease conditions of each patient (e.g., setting a lower target for energy intake for
obese or elderly patients). (grade A; consensus)
Equations used for calculation of energy intake:
Amount of energy intake = ideal body weight × physical activity level
Ideal body weight (kg) = [height (m)]2 × 22
Physical activity level (kcal/kg/ideal body weight)
25-30: low-intensity exercise (e.g., jobs involving deskwork)
30-35: moderate-intensity exercise (e.g., jobs involving standing work)
35: high-intensity exercise (e.g., jobs involving heavy physical work)
5. Composition of Macronutrients
In formulating a diet for patients with diabetes, it is to be ensured that carbohydrates account for 50-60%
of the total energy4, while proteins account for 1.0 to 1.2 g/kg/ideal body weight, with the rest of the
energy accounted for by fats. (grade A)
○ Carbohydrates: Given that there is a paucity of evidence as to the intake of carbohydrates in Japan and
there is no consensus as to the lower normal limits for carbohydrate intake, it is desirable that
carbohydrates not more than 60% of the total energy intake; that the intake of sweets, jams or soft drinks
be minimized as they contain a large amount of sucrose that leads to an elevation of triglyceride levels;
and that the intake of fruit be limited to up to 1 unit (80kcal)/day, given that fruits currently on markets
often contain a large amount of sugar as a result of selective breeding.
○ Proteins: While there is a paucity of evidence for protein intake, it is common practice to recommend 1.0
to 1.2 g/kg/ideal body weight of proteins. Intake of less animal protein and more plant protein (e.g.,
soybean products) is recommended to prevent atherosclerosis.5 Protein-restricted diet is recommended
for patients with diabetic nephropathy.
Saturated and polyunsaturated fats: It is recommended that saturated and polyunsaturated fats account
for not more than 7% and 10% of the total energy intake, respectively. (grade B; consensus)
n-3 polyunsaturated fatty acids (e.g., eicosapentaenoic acid [EPA], docosahexaenoic acid [DHA]) which
abound in fish are shown to be effective in lowering glucose and triglyceride levels.6,7
6. Salt Intake
Excessive salt intake may lead to the onset of vascular diseases through elevation of blood pressure as
well as to an increase in appetite. Therefore, salt intake should generally be limited, and restricted to 6
g/day in patients with diabetes and hypertension and in those with overt nephropathy or more severe
disease. (grade B; consensus)
7. Dietary Fiber Intake
Intake of dietary fiber (20 to 25 g/day) is shown to be effective in improving glycemic control as well as in
lowering serum lipid levels (cholesterol and triglycerides).8 (grade B)
Daily intake of 350 g or more of vegetables should be targeted. During meals, taking vegetables first helps
to reduce postprandial glucose increases, HbA1c values, and body weight.9
8. Intake of Varied Foodstuffs
To avoid vitamin or mineral deficiency, it is to be ensured that patients take as many kinds of food items
as possible. (grade B; consensus)
1. Diet Therapy in General
Diet therapy is the cornerstone of therapy for all patients with diabetes. Practicing an appropriate diet
improves glycemic control.1,2 (grade A)
2. Individualized Diet Therapy
Individualized diet therapy according to the lifestyle of each patient is essential for successful
introduction and continuation of the recommended diet therapy and requires, first and foremost, that
each patient be interviewed adequately about his/her dietary habits, such as food preferences and diet
timetables as well as his/her physical activity level. (grade A; consensus)
○ The elderly are often associated with disturbance of taste, smell, and mastication, reduced secretion of
saliva and gastric acid, and impaired renal and hepatic function, which leads to malnutrition and
sarcopenia. Therefore, it is required that diet therapy for the elderly be so formulated as to avoid the risk
of malnutrition.
3. Diet Instructions by Registered Dietitians
In clinical practice, diet instructions involving a registered dietitian are useful for glycemic control.3
(grade B)
The Food Exchange Lists, edited by the Japan Diabetes Society, is commonly used for diet instructions.
However, if it is difficult for patients to understand the Food Exchange Lists, actual food products or food
models may be used to give instructions. (grade B; consensus)
4. Determination of the Amount of Energy Intake
● The amount of energy intake is to be determined by a physician, with consideration given to his/her
glucose levels, blood pressure, serum lipid levels, height, body weight, age, sex, complications, and energy
expenditure (physical activity), as well as the amount of prior food intake. It must be also determined
individually to meet disease conditions of each patient (e.g., setting a lower target for energy intake for
obese or elderly patients). (grade A; consensus)
Equations used for calculation of energy intake:
Amount of energy intake = ideal body weight × physical activity level
Ideal body weight (kg) = [height (m)]2 × 22
Physical activity level (kcal/kg/ideal body weight)
25-30: low-intensity exercise (e.g., jobs involving deskwork)
30-35: moderate-intensity exercise (e.g., jobs involving standing work)
35: high-intensity exercise (e.g., jobs involving heavy physical work)
5. Composition of Macronutrients
In formulating a diet for patients with diabetes, it is to be ensured that carbohydrates account for 50-60%
of the total energy4, while proteins account for 1.0 to 1.2 g/kg/ideal body weight, with the rest of the
energy accounted for by fats. (grade A)
○ Carbohydrates: Given that there is a paucity of evidence as to the intake of carbohydrates in Japan and
there is no consensus as to the lower normal limits for carbohydrate intake, it is desirable that
carbohydrates not more than 60% of the total energy intake; that the intake of sweets, jams or soft drinks
be minimized as they contain a large amount of sucrose that leads to an elevation of triglyceride levels;
and that the intake of fruit be limited to up to 1 unit (80kcal)/day, given that fruits currently on markets
often contain a large amount of sugar as a result of selective breeding.
○ Proteins: While there is a paucity of evidence for protein intake, it is common practice to recommend 1.0
to 1.2 g/kg/ideal body weight of proteins. Intake of less animal protein and more plant protein (e.g.,
soybean products) is recommended to prevent atherosclerosis.5 Protein-restricted diet is recommended
for patients with diabetic nephropathy.
Saturated and polyunsaturated fats: It is recommended that saturated and polyunsaturated fats account
for not more than 7% and 10% of the total energy intake, respectively. (grade B; consensus)
n-3 polyunsaturated fatty acids (e.g., eicosapentaenoic acid [EPA], docosahexaenoic acid [DHA]) which
abound in fish are shown to be effective in lowering glucose and triglyceride levels.6,7
6. Salt Intake
Excessive salt intake may lead to the onset of vascular diseases through elevation of blood pressure as
well as to an increase in appetite. Therefore, salt intake should generally be limited, and restricted to 6
g/day in patients with diabetes and hypertension and in those with overt nephropathy or more severe
disease. (grade B; consensus)
7. Dietary Fiber Intake
Intake of dietary fiber (20 to 25 g/day) is shown to be effective in improving glycemic control as well as in
lowering serum lipid levels (cholesterol and triglycerides).8 (grade B)
Daily intake of 350 g or more of vegetables should be targeted. During meals, taking vegetables first helps
to reduce postprandial glucose increases, HbA1c values, and body weight.9
8. Intake of Varied Foodstuffs
To avoid vitamin or mineral deficiency, it is to be ensured that patients take as many kinds of food items
as possible. (grade B; consensus)
References
1. United Kingdom Prospective Diabetes Study (UKPDS) Group. UK Prospective Diabetes Study 7. Response
of fasting plasma glucose to diet therapy in newly presenting type II diabetic patients. Metabolism
1990;39:905-912. (level 3)
2. Wing RR, Blair EH, Bononi P, et al. Caloric restriction per se is a significant factor in improvements in
glycemic control and insulin sensitivity during weight loss in obese NIDDM patients. Diabetes Care
1994;17:30-36. (level 1)
3. Kulkarni K, Castle G, Gregory R, et al. Nutrition Practice Guidelines for Type 1 Diabetes Mellitus positively
affect dietitian practices and patient outcomes. The Diabetes Care and Education Dietetic Practice Group. J
Am Diet Assoc 1998;98:62-70/quiz 72-74. (level 3)
4. Anderson JW, Randles KM, Kendall CW, et al. Carbohydrate and fiber recommendations for individuals
with diabetes: a quantitative assessment and meta-analysis of the evidence. J Am Coll Nutr 2004;23:5-17.
(level 1)
5. Fung TT, van Dam RM, Hankinson SE et al: Low-carbohydrate diet and all-cause and cause specific
mortality: two cohort studies. Ann Intern Med 153: 289-298, 2010. (level 2)
6. Garg A. High-monounsaturated-fat diets for patients with diabetes mellitus: a meta-analysis. Am J Clin Nutr
1998;67(Suppl):577S-582S. (level 1)
7. Friedberg CE, Janssen MJ, Heine RJ, et al. Fish oil and glycemic control in diabetes: a meta-analysis.
Diabetes Care 1998;21:494-500. (level 1)
8. Chandalia M, Garg A, Lutjohann D et al: Beneficial effects of higher dietary fiber intake in patients with
type 2 diabetes mellitus. N Engl J Med 342:1392-1398, 2000. (level 1)
9. Imai S, Matsuda M, Hasegawa G, et al. A simple meal plan of “eating vegetables before carbohydrates” was
more effective for achieving glycemic control than an exchange-based meal plan in Japanese patients with
type 2 diabetes. Asia Pac J Clin Nutr 2011;20:161-168. (level 3) D I
