Q. A lot of people eat canned tuna when dieting. I'm curious about the exact reasons why it's considered good for weight loss.

I used to stock up on boxes of canned tuna myself when I was dieting, but at some point, I stopped losing weight and my face would be swollen every morning. To avoid such mistakes, it is important to understand how our body's mechanisms work. From a Western medical perspective, tuna has high protein content that triggers 'Diet-Induced Thermogenesis,' meaning the body expends significant energy just to digest it. However, canned tuna is often packed with preservative oils and sodium. These components can trigger systemic inflammation and affect insulin resistance, potentially turning your body into one that resists weight loss despite the high protein intake. In Traditional Korean Medicine (TKM), this situation is explained through the relationship between Bi-heo (Spleen Deficiency) and Dam-eum (phlegm-fluid). A state where the Spleen's digestive and metabolic functions are weakened is called Bi-heo. In this state, excessive consumption of processed foods causes undigested residues to become Dam-eum, which accumulates as waste throughout the body. As Dam-eum increases, it obstructs the circulation of Qi and blood, leading to Eo-hyeol (blood stasis) and a significant drop in metabolic rate. Eventually, you end up feeling heavy and lethargic even if you aren't eating much. Therefore, when eating canned tuna, it is best to squeeze out as much oil as possible or rinse it once with hot water. Since tuna has a 'cold' property, pairing it with 'warm' natured vegetables to support Spleen function is a wise approach. True dieting begins with carefully observing your own digestive health.