The object of this study is to compare "100g Standard Noodles " with traditional carbohydrates including 75g glucose solution in 300ml water and 100g steamed bread in the diagnosis of diabetes mellitus.

In this study, we will compare the different effects of "100g Standard Noodles Tolerance Test"and "75g Oral Glucose Tolerance Test"on plasma glucose, insulin, c- peptide level and the relevant hormones level including glucagon-like peptide-1( GLP-1) and glucagon. Besides, in part of the subjects, the difference between "100g Steamed Bread Tolerance Test", "100g Standard Noodles Tolerance Test" and "75g Oral Glucose Tolerance Test" will be further evaluated.

Inclusion Criteria:

Inclusion Criteria:

For healthy subjects:

1. Between 16-70 years old.
2. No weight fluctuation greater than 5% within 3 months.
3. Understand and voluntarily sign an informed consent document prior to any study related assessments/procedures .

For subjects with impaired glucose regulation(IGR):

1. Between 16-70 years old.
2. Impaired fasting glucose(IFG):6.1mM(109mg/ml)≤fasting plasma glucose(FPG)<7.0mM(126mg/ml),or impaired glucose tolerance(IGT):7.8mM（140mg/ml）≤2h plasma glucose(2hPG)<11.1mM(200mg/dl),or both.
3. No weight fluctuation greater than 5% within3 months.
4. Keep stable antidiabetic therapy for at least 2 months.
5. Understand and voluntarily sign an informed consent document prior to any study related assessments/procedures .

For subjects with type 2 diabetes mellitus(T2DM):

1. Between 16-70 years old.
2. T2DM:diabetic symptoms plus random blood glucose(RBG)≥11.1mM,or FPG ≥7.0mM(126mg/dl),or 2hPG ≥11.1mM(200mg/dl).
3. No weight fluctuation greater than 5% within 3 months.
4. Keep stable antidiabetic therapy at least for 2 months.
5. Understand and voluntarily sign an informed consent document prior to any study related assessments/procedures.

For subjects with type 1 diabetes mellitus(T1DM):

1. Between 16-70 years old.
2. T1DM:diabetic symptoms plus RBG≥11.1mM,or FPG ≥7.0mM(126mg/dl),or 2hPG ≥11.1mM(200mg/dl).
3. Present at least one positive antibody of β cell including ICA,IAA,GADA,IA-2A and IA-2βA.
4. No weight fluctuation greater than 5% within 3 months.
5. Keep stable antidiabetic therapy for at least 2 months.
6. Understand and voluntarily sign an informed consent document prior to any study related assessments/procedures.

Exclusion Criteria:

For healthy subjects:

1. Be diagnosed with diabetes or IGR in late 3 months.
2. With any significant medical condition,laboratory abnormality,or psychiatric disorders that will prevent the subject from participating in the study.
3. Any medical or surgical conditions possibly affecting the experiment result.
4. Participated in a clinical study involving administration of medication within 90 days.
5. Donated blood or plasma or had any other significant blood loss within 2 months.
6. Any clinically significant allergic diseases.
7. Recently drug or alcohol abuse(>35unit/week,1unit=8 g alcohol@1 standard drink@250ml beer@140ml wine@25ml strong alcohol drink like whiskey.)
8. Smokers or users of other tobacco products in the 3 months prior to screening.

For IGR and DM:

1. History of pancreatic diseases such as pancreatic cancer or pancreatitis.
2. Suffered from acute complications such as diabetic ketoacidosis and hyperosmolar coma within 3 months.
3. With any significant medical condition，laboratory abnormality,or psychiatric disorders that will prevent the subject from participating in the study.
4. Malignant tumor.
5. Being allergic to experiment arms.
6. Recently drug or alcohol abuse(>35unit/week,1unit=8 g alcohol@1 standard drink@250ml beer@140ml wine@25ml strong alcohol drink like whiskey.)