Three percent weight reduction is the minimum requirement to improve health hazards in obese and overweight people in Japan

Summary Objective Adequate goal-setting is important in health counselling and treatment for obesity and overweight. We tried to determine the minimum weight reduction required for improvement of obesity-related risk factors and conditions in obese and overweight Japanese people, using a nationwide intervention programme database. Methods Japanese men and women ( n =3480; mean age±standard deviation [SD], 48.3±5.9 years; mean body mass index±SD, 27.7±2.5kgm −2 ) with "Obesity Disease" or "Metabolic Syndrome" participated in a 6-month lifestyle modification programme (specific health guidance) and underwent follow-up for 6 months thereafter. The relationship between percent weight reduction and changes in 11 parameters of obesity-related diseases were examined. Results Significant weight reduction was observed 6 months after the beginning of the programme, and it was maintained for 1 year. Concomitant improvements in parameters for obesity-related diseases were also observed. One-third of the subjects reduced their body weight by ≥3%. In the group exhibiting 1% to Conclusion The 6-month lifestyle modification programme induced significant weight reduction and significant improvement of parameters of obesity-related diseases. All the measured obesity-related parameters were significantly improved in groups with 3% to