Objective: To examine the influence of famine exposure during early life on BMI in adulthood. Methods: A total of 94 052 participants recruited in the baseline survey of China Kadoorie Biobank were included in this study. The participants who were born between October 1956 and September 1958, between October 1959 and September 1961 and between October 1962 and September 1964 were classified as group born before famine, group born during famine and group born after famine (control group). The regression coefficients and 95% confidence intervals (CIs) for BMI of famine exposure groups were estimated by linear regression model. And P values for interaction between famine and smoking, alcohol use, physical activity were estimated by likelihood ratio tests. Results: Compared with the group born after famine, in females, the group born during famine had higher BMI (coefficient: 0.12, 95% CI: 0.03-0.22) after adjusting other impact factors. Except physical activity (interaction: P<0.077), both smoking and alcohol use had modification effects on the associations between famine exposure and BMI (interaction: all P<0.001). Conclusion: Famine exposure during early life, especially during fetal period, might increase risks of overweight and obesity in females. Therefore, it is important to ensure the adequacy of nutrition during early life to prevent overweight or obesity in adulthood.