Born in 1960's in a small village in Northern China, I had experienced the shortage of food. I went to boarding school for my high school and everyone had the same amount of food at every meal, regardless of one’s gender or size. Therefore, the most effective way to fight hunger was to tighten my belt. My older siblings did not attend boarding school and had more to eat, which was probably why I was the shortest one among three siblings.
Entering medical school, I was primarily known as an athletic guy. I often received more food with the same amount of money because staff at the dining hall simply liked me very much and felt I needed more food due to my consumption of energy in sports. Sometimes, I would get more food than I can eat and I would simply share with friends. With the increase of food supply, I surprisingly grew an extra inch taller during my medical school years.
After graduating from medical school, I made some money and could afford more food-meaning I was supposed to gain more weight. However, I always remembered to tighten my belt. That’s why my neighbors often asked if I was eating enough, because I looked so “thin” while most people at my age have been carrying a supersized belly, a sign they were well off. Though annoyed, I'd always jokingly say the same thing, “I am still working up in life.” By tightening my belt, I am still able to fit in the pants I used to wear during high school :)
The original purpose of tightening one’s belt might have been to prevent pants falling off. However, I have my own understanding of the idiom from my personal and medical perspectives: First of all, by tightening your belt, you’d maintain a relatively consistent volume in your stomach for the amount of food you should eat. Secondly, when tightening your belt, you can keep your stomach between your waistline and your diaphragm so that it would not stretch and hold more food than it should otherwise. Moreover, your stomach would become smaller and you'd feel fuller sooner when eating your meals.
My personal observation of the obesity epidemic in the developed countries is that it comes from food surplus and over-consumption. This is why some obese patients choose to reduce the volume of their stomach. Whenever I treat overweight patients, I always wonder: if one can simply tighten the belt to prevent obesity, why would one choose to undergo tummy tuck or even bariatric surgery?
For the sake of your stomach, please tighten your belt.