Objective To understand the currency level of snacks behavior in young and middle-aged patients with diabetes and to provide evidence for diabetic patients to formulate individualized diet management education programs. Methods From January to December 2021, 438 young and middle-aged patients with diabetes admitted to endocrinology department of one hospital in Jiangsu province were into this study by convenience sampling method. The questionnaire survey was conducted with a demographic questionnaire, self-made snacks behavior questionnaire with diabetes and Chinese version of diabetes specific quality of life scale. Results Among those 438 young and middle-aged patients, 4.34% never ate breakfast per week. 73.97% self-reported that they have the habit of extra snacks. Some of them snacked every day, and the proportion were morning snacks (16.36%), afternoon snacks (32.1%) and bedtime snacks (24.07%) respectively. The main reasons for snacking were hunger (57.41%), habits (41.05%) and physiological needs (13.58%). Sex, age, type of diabetes and diabetic complications are the main influencing factors of extra snacks.Comparison of serum glucose and lipids metabolism in young and middle-aged patients with different snacking behaviors found that the serum triglyceride levels in the snack group was lower than that in the non-snack group and the serum HBA1c was higher than non-snack group, the difference was statistically significant (P＜0.05). The snack group scored in both total score, psychological and spiritual and therapeutical dimensions were all higher than the non-snack group, that means their quality of life is lower, the difference was statistically significant (P＜0.05). Conclusion Snacking of young and middle-aged diabetic patients is not optimistic, we should pay attention to the impact of snacking behavior on serum glucose and lipid metabolism and provid more accurate diet management plan for diabetes.