The aim of this study is to investigate the effects of immature ponkan (Citrus reticulate) extract on body weight and body fat in overweight and obese adults.

This randomized, placebo-controlled clinical trial will be conduct for 8 weeks with three hundred adults. Subjects will be recruited and randomly assigned into three groups: (1) placebo, n = 100; (2) immature ponkan extract, n=100; (3) immature ponkan extract with time restricted feeding, n=100. During the 8 weeks intervention, the subjects should take 25mL liquid of placebo or immature ponkan extract a day (drink 25mL for once, and once a day). The two drinks are supplied in aluminum foil packages, and both the products taste the same. Subjects also should complete the assessment of anthropometric measurement, intestinal questionnaire , food record, feces and blood collection at week 0, 4 and week 8.

Inclusion Criteria:

• male or female
• aged 20-60 years old
• body mass index is greater than or equal to 24 kg/m2, or body fat more than 30%

Exclusion Criteria:

• Subjects diagnosed with cancer and on curative care.
• Subjects diagnosed with heart disease and on curative care.
• Subjects who use other drugs whose pharmacological effects may affect the experiment or may aggravate the effects of the drug.
• Subjects with systemic infection requiring antibiotics.