Obesity is closely related to many chronic diseases such as hypertension, coronary heart disease, hyperlipidemia, type 2 diabetes, fatty liver, certain types of tumors, etc, which are associated with adverse health outcomes. Limiting energy intake is one of the most important treatment measures for weight loss. The fruits of Aronia melanocarpa (Aronia berries) have been found to show multiple bioactivities potentially beneficial to human health, including antidiabetic, anti-infective, antineoplastic, antiobesity, antioxidant and gut microbiota-regulating activities. Thus, it is worth investigating whether consumption of aronia melanocarpa extract have additional benefits in improving anthropometric indicators, glucose and lipid metabolism, inflammatory status, adipocyte cytokines, and intestinal microbiota in obese individuals on the basis of an energy-restricted diet.

Obese individuals will be divided into intervention group and control group in this 8-week trial. Both groups will be given an energy-restricted diet, with an additional dose of aronia melanocarpa extract in capsules in intervention group and an additional dose of maltodextrin in capsules in control group.

Fecal and blood samples from participants before and after the intervention will be collected for the analysis of gut microbiota, glucose and lipid metabolism, inflammatory status, and adipocyte cytokines

Inclusion Criteria:

• Aged 18-40 years
• Simple obese individuals with stable body weight in the last three months before enrollment (28.0kg/m2 ≤ BMI <35.0kg/m2)
• Impaired fasting blood glucose: Within the last three months before enrollment, the venous fasting blood glucose was between 6.1 and 7.0 mmol/L, and the 2-hour postprandial blood glucose was<7.8 mmol/L and the glycated hemoglobin (HbA1c) was < 6.5%

Exclusion Criteria:

• Diagnosed patients with diabetes or those who use hypoglycemic drugs
• Patients with concomitant hyperthyroidism or hypothyroidism, or those taking thyroxine tablets
• Those who apply glucocorticoids within 12 weeks
• Individuals with suspected renal dysfunction (female: serum creatinine ≥ 84 µ mol/L; male: serum creatinine ≥ 104 µ mol/L) or suspected liver dysfunction (elevated transaminase >3 times normal or cirrhosis)
• Secondary obesity (such as thalamic diseases, pituitary diseases, Cushing's syndrome, etc.)
• Previous weight loss surgeries
• Pregnant or lactating individuals
• Individuals with confirmed mental illness or eating disorders
• Women with polycystic ovary syndrome
• Individuals who are allergic or intolerant to experimental products
• Lactose intolerant individuals
• Those who have taken probiotics and/or probiotic drugs or supplements within one month before enrollment
• Those who fail to use intervention agents according to the study protocol or have severely incomplete visit records