Recently, a team of researchers, including Ida Donkin from the University of Copenhagen, Denmark, found that epigenetic changes in the spermatozoa of obese people after bariatric surgery. Epigenetics is the study of heritable changes in gene expression in the absence of changes in the nucleotide sequence of genes. Nowadays, obesity and related metabolic diseases are increasing in the population due to the high protein and high energy diet structure and sedentary lifestyle habits. It was found that the offspring of obese fathers are generally genetically influenced and have a high probability of acquiring obesity and related metabolic diseases independent of the mother’s weight; this indicates that paternal factors have more influence on obesity and obesity-related traits on the obesity of the offspring; in rodents Studies and epidemiological data show that paternal nutritional status directly affects offspring health, suggesting that environmentally acquired epigenetic phenomena are transmitted through gametes; exercise and nutritional status induce dramatic changes in DNA methylation in human skeletal muscle and fat, confirming that environmental factors reshape the epigenome of somatic tissues, yet whether obesogenic factors like excessive energy and sedentary lifestyles can alter the the epigenome of human gametes is still unknown. The team of Ida Donkin et al. found that histone localization of sperm in obese versus lean men was not altered, whereas small non-coding RNAs (sncRNAs) in obese sperm were altered, and that such alterations may co-regulate gene expression related to behavior and food intake and thus be involved in inducing obesity in offspring; also found that in obese male sperm More interestingly, when obese individuals lost weight through gastric bypass surgery (GBP), the methylation status of 1509 unique genes was altered one week after the surgery, and even more one year after the surgery, 3910 unique genes were differentially expressed in sperm, suggesting that weight loss can induce sperm epigenetic genome alterations, and sperm DNA methylation undergoes rapid remodeling after GBP surgery, suggesting that epigenetic modifications can occur in the final stages of sperm maturation. Therefore, men who are obese should also lose weight for the health of their offspring.