The world prevalence of obesity in adult population in 2016 was 650 million while in Indonesia, it has increased from 14,8 percent to 21,8 percent in 2018. Obesity is an established risk factors for metabolic and non communicable- diseases. The purpose of this research was to assess the different effect on waist circumference, insulin resistance and oxidative stress marker between fasting (intervention) group and not fasting (control) group after 8 weeks 5:2 intermittent fasting (IF) among obese male workers.

Intermittent fasting is eating pattern in that cycles between periods of fasting and eating. 5:2 intermittent fasting (IF) is a form of time-restricted fasting which no calories are consumed for at least 14 hours (for 4 am to 6 pm) will done in two non-consecutive days days per week, followed by ad libitum intake on the remaining days, with water restriction too.

Participants will be distributed to each group by simple randomization. This study will access the characteristic data, dietary intake and physical activity from the participants. Anthropometry and blood sample (for insulin resistance (HOMA-IR) and oxidative stress (malondialdehyde and catalase)) were taken at baseline and at the end of the study. Participants from each group will gets counseling at the second week of intervention and they will follow up to 8 weeks with control and evaluation form.

Inclusion Criteria:

• Men aged 30-59 years
• Has a BMI ≥ 25 kg/m^2
• Has a waist circumference of ≥ 90 cm
• Willingness to participate in the whole study by signing informed consent

Exclusion Criteria:

• Doing regular fasting (2 days a week) for 12 weeks before the study begins.
• In a certain diet at the moment
• Participants who are taking drugs that can affect blood sugar, insulin, and drugs (steroids, beta blockers, adrenergics), vitamins or herbal supplements and other drugs that affect oxidative stress.
• Participants suffering from obesity with complications such as impaired liver function, impaired kidney function, heart disease and type 2 diabetes mellitus are known through anamnesis and physical examination as well as fasting blood sugar checks.
• Participants that has a fever with temperatures> 37.5 ℃

menstruating women will lose blood, so if they still asked to fast, it can endanger themselves because the nutrition is getting less