Affordable and accessible behaviour-based interventions that do not overwhelm or demoralise overweight/obese individuals are needed. Combining clothing with behaviour change techniques might be an option. This is because clothing is a social norm, and clothing and motivation for weight loss are associated with the common desire to look better. Therefore, we conducted a single-blind randomised controlled trial to examine the effect of an intervention that combined behaviour change techniques, including simplified goal setting and self-monitoring, with a body compression corrective garment (BCCG), which exerts continuous but minimal tactile pressure on the hips and abdomen. We enrolled healthy community-dwelling adults with a body mass index ≥ 25 kg/m2 and assigned 35 and 34 participants to the intervention and control groups, respectively. The reduction in body weight was 1.3 kg more in the intervention group than in the control group after the 12-week intervention period (p < 0.05, repeated-measures mixed model). In addition, eating behaviour and body appreciation showed significant improvement in the intervention group compared with the control group. Our newly developed intervention improved eating behaviour and body appreciation and reduced the body weight of overweight/obese participants. Wearing a BCCG seems to facilitate behavioural changes and lead to weight loss.