Type 2 diabetic patients

HbA1C > 6.5%

Duration of diabetes: 0.5 to 30 years

Subjects ≥ 26 and ≤ 65 years of age

BMI: > 26 kg/m2

All oral antidiabetic treatments and will be allowed, not insulin treatment

Normal liver and kidney function

Normal thyroid function

Stable physical activity pattern during the three months immediately preceding study

No metabolic disease other than diabetes

Usually wakes up between 06:00 and 07:00 and goes to sleep between 22:00 and 24:00.

Normal TSH and FT4 levels

No shift work within 5 years of the study

Did not cross time zones within 1 month of the study

Acceptable health beside diabetes based on interview, medical history, physical examination, and laboratory tests

Read and understood the informed consent form and signed it voluntarily

Healthy non diabetic, and not known as diabetic

Fasting glucose <100 mg/dl

HbA1C <5.7 %

Not taking any antidiabetic drugs

Subjects ≥ 26 and ≤ 65 years of age

BMI: <26 kg/m2

Normal liver and kidney function

Normal TSH and FT4 levels

Usually wakes up between 06:00 and 07:00 and goes to sleep between 22:00 and 24:00.

No shift work within 5 years of the study

Did not cross time zones within 1 month of the study

Acceptable health based on interview, medical history, physical examination, and laboratory tests

Read and understood the informed consent form and signed it voluntarily

Clinically significant pulmonary, cardiac, renal, hepatic, neurologic, psychiatric, infectious, malignant disease

Type 1 diabetes

Treatment with Insulin

Serum creatinin level > 1.5 mg/dl

Pregnancy or lactation

Illicit drug abuse or alcoholism

Subjects on steroid treatment

Subjects known by the principal investigator to be unable to cooperate for any reason.

Abnormal liver function tests defined as an increase by a factor of at least 2 above the upper normal limit of alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST)

Night or rotating shift work

Jet lag during the 2 week period immediately prior to study onset