Here is the design of a clinical trial:

Official Title: Electro-acupuncture for Central Obesity: a Single Blinded Randomized Sham-controlled Clinical Trial

Included conditions:
- Central Obesity

Study Armgroups:
- {'label': 'Acupuncture group', 'type': 'EXPERIMENTAL', 'description': 'Body electro-acupuncture will be conducted for 2 sessions per week over 8 consecutive weeks.\n\nBody electro-acupuncture will choose eight acupoints as Tianshu(ST-25), Daheng(SP-15), Daimai(GB-26), Qihai(CV-6), Zhongwan(CV-12), Zusanli (ST-36), Fenlong(ST-40), Sanyinjiao(SP-6).Disposable acupuncture needles (verum acupuncture needles asia-med Special No. 16 with 0.30 x 0.30mm matching the Streitberger sham-needles) will be inserted at a depth of 10-25 mm into the points.\n\nWe will also deliver electrical stimulation with dense-disperse waves with 50Hz at 10 volts through electrical acupuncture stimulation instrument (ES-160 6-Channel Programmable Electro-acupuncture) to the abdominal points. The bodily needles will be retained for 30 minutes.', 'interventionNames': ['Other: acupuncture']}
- {'label': 'sham-acupuncture group', 'type': 'PLACEBO_COMPARATOR', 'description': 'As to the participants allocated to control group, Streitberger\'s non-invasive acupuncture needles (Gauge 8 x 1.2" / 0.30 x 30 mm) will be applied to act as sham control at the same acupoints with same stimulation modality. However, the needles will be only adhered to the skin instead of insertion. The validity and credibility of this model has been well demonstrated.', 'interventionNames': ['Other: acupuncture']}

Interventions:
- {'type': 'OTHER', 'name': 'acupuncture', 'description': 'Body electro-acupuncture will choose eight acupoints as Tianshu(ST-25), Daheng(SP-15), Daimai(GB-26), Qihai(CV-6), Zhongwan(CV-12), Zusanli (ST-36), Fenlong(ST-40), Sanyinjiao(SP-6).Disposable acupuncture needles (verum acupuncture needles asia-med Special No. 16 with 0.30 x 0.30mm matching the Streitberger sham-needles) will be inserted at a depth of 10-25 mm into the points.\n\nWe will also deliver electrical stimulation with dense-disperse waves with 50Hz at 10 volts through electrical acupuncture stimulation instrument (ES-160 6-Channel Programmable Electro-acupuncture) to the abdominal points. The bodily needles will be retained for 30 minutes.', 'armGroupLabels': ['Acupuncture group', 'sham-acupuncture group']}

Primary Outcomes:
- {'measure': 'Changes in waist circumference', 'description': 'Waist circumference will be measured around the abdomen at the level of the umbilicus (belly button).', 'timeFrame': '0,1,2,3,4,5,6,7,8, 11, 15,18, 21, 24 weeks'}

Please estimate the sample size based on the assumption: 
80% efficacy, 5% alpha (two tails), 20% dropout rate
Sample size
        The calculation of the sample size is based on the measurement of the main results.
        Our preliminary clinical study of 72 participantsâ results [28] showed that electroacupuncture combined with auricular acupressure decreased from baseline to week 8 by 1.57% (sdâ=â0.025) in WC, compared with 0.14% (sd. = 0.041) in the sham group). Considering 80% efficacy and 5% alpha (two tails), at least 70 subjects in each group were required to test its importance. Considering a 20% dropout rate, we plan to recruit 84 subjects per group, for a total of 168 subjects. Calculations were performed using PASS 11 software in Caseville, Utah, USA.