The reasonable combination of macronutrients including carbohydrates, proteins and fat, is the basis of rational diet and beneficial to treatment of metabolic diseases including obesity and diabetes. Endocrine hormones play pivotal roles in regulation of nutrients metabolism and energy homeostasis. However, the dynamic metabolism following the consumption of macronutrients and the relationship between various metabolites and endocrine hormones during these procedures yet to be adequately explained nowadays. Therefore, in this study, the investigators selected glucose, protein, fat and mixed meal tolerance test (MMTT) for the loading tests, endocrine hormones and metabolites were detected to profile the molecular changes in the plasma. The investigators aimed to explore the nutrient processing patterns of various macronutrients and determine the interaction between metabolic hormones and metabolites.

Inclusion Criteria:

1. Those who agree to participate in the study and sign informed consent.
2. Age between 20 and 65 year.
3. Fasting plasma glucose < 7.0mmol/l, and 2-hour postprandial plasma glucose < 11.1mmol/l.
4. BMI > 18 kg/m2.

Exclusion Criteria:

1. History of diabetes.

2. Pregnant or lactating women.

3. The subjects had not received oral/systemic corticosteroids for 7 consecutive days during the last 6 months.

4. Subjects were taking medication known to affect glucose metabolism.

5. Subjects who take strong inhibitors of cytochrome P450 (CYP)3A4/5, for example, ketoconazole, azanaway, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, ritonavir, saquinavir and telithromycin.

6. Patients with either of the following characteristics of severe hepatic disease:

   i. Two consecutive abnormal hepatic function results during recent four weeks, with ALT or AST three times the upper limit of the institutions normal reference ranges.

   ii. Hepatic excretion dysfunction (eg. hyperbilirubinemia) and/or synthesis dysfunction, or other decompensated liver disease.

   iii. Acute viral hepatitis, autoimmune hepatitis, and alcoholic hepatitis

7. Patients with moderate and severe renal impairment, and end-stage renal disease (serum creatinine > 194.5 mmol/L, or serum potassium > 5.5 mmol/L).

8. New York Heart Association (NYHA) functional class III or IV congestive heart failure.

9. History of acute or chronic pancreatitis.

10. History of gastrointestinal disorders: gastroenterostomy, enterectomy, ileus and intestinal ulcers.

11. Subjects with previously diagnosed malignancy within the past 5 years.

12. Any other reasons that the investigator considered inappropriate to participate in the study.