In South Korea, it is quite rare to find obese or overweight young men. This is largely due to the fact that almost all young men are slim, which in turn influences societal norms and expectations. As a result, many women also tend to maintain slim physiques, a phenomenon known as societal mirroring effects. This concept suggests that people often unconsciously imitate the behaviors and appearances of those around them, leading to a collective standard of body image.

The primary reason for the slim physiques of Korean men is their mandatory military service. In South Korea, it is mandatory for all able-bodied men in their early 20s to serve in the military, with the exception of individuals with disabilities or chronic illnesses. This compulsory service is a significant rite of passage and a national duty that lasts for 1 year and 6 months. During this period, the daily routine is highly regimented, beginning at 6 a.m. and ending at 10 p.m. The schedule is packed with various physical training exercises, military drills, and professional tasks, which significantly contribute to weight loss and muscle gain. The disciplined lifestyle and intense physical activity help transform many young men into lean and muscular individuals.

The intense physical activity and structured lifestyle often lead to significant weight loss. Many men who may have gained weight before their enlistment find themselves becoming much leaner during their service. After completing their military service, these men often continue to maintain their slim and fit bodies, carrying the habits and discipline they acquired during their service into their civilian lives.

This transformation is not just temporary; the discipline and habits formed during military service often help maintain a healthier physique well into middle age and beyond. For example, the author of this book weighed 90 kg (198 lbs) when he enlisted. However, within just three months of rigorous training and a disciplined lifestyle, his weight dropped to 60 kg (132 lbs). Even now, as a middle-aged man, he maintains a healthy weight of 70 kg (154 lbs), a testament to the lasting impact of his military service.

This widespread phenomenon of slim and fit young men sets a societal standard that influences the body image and fitness goals of the broader population, including women.

If you are a single woman and wish to maintain a slim physique well into middle age and beyond, I have two strategies that might help you achieve this goal.

First, consider excluding obese men from your potential marriage partners and instead, choose to marry a man who is slim and muscular. The idea here is that by surrounding yourself with a partner who already embodies the physical traits you desire, you are more likely to adopt and maintain similar habits and lifestyle choices that contribute to a healthy body.

Second, even after marriage, it is important to avoid contributing to weight gain in your partner. This means encouraging healthy eating habits and an active lifestyle for both of you. By helping your husband maintain a slim and fit body, there is a high probability that you will also naturally adopt these healthy habits, leading to a slim physique for yourself as well. The concept of societal mirroring effects suggests that people often unconsciously imitate the behaviors and appearances of those around them, so maintaining a healthy environment at home can be beneficial for both partners.

By following these strategies, you can create a supportive and health-conscious environment that promotes long-term physical well-being for both you and your partner.