The purpose of this project is to use white-skinned sweet potato as the main material for weight control for overweight and obesity, the non-communicable diseases (cardiovascular diseases, cancers, chronic respiratory diseases and diabetes) are also included. All high quality sweet potato are provided by CAES in Taiwan to produce special nutrient food and health food that to do functional study in Shih Chien University and Taipei Medical University. In this study, the investigators will recruit overweight and obesity subjects that divide into white sweet potato group (experimental group) and no intervention group (control group) by using randomized, parallel and open clinical study in sixty days.

All subjects will be evaluated the body weight and clinical nutrition assessment such as postural measurement, urine test and blood biomarker examination.

Inclusion Criteria:

• 24≦ BMI≦30

Exclusion Criteria:

• Pregnant and lactating women
• Patients within six months after surgery
• Mental illness or depression
• Suffering from cancer, ulcers, acute respiratory infections, dialysis, acute hepatitis and other diseases
• Those who have taken "additional nutritional supplements" habit

The adverse event data were collected from the participants during intervention and assessed after 24 weeks.

No adverse event.

Small sample size and trial duration that may cause impose an obstacle in the detection of significant changes of the study measure.