I'm told to avoid eating out while dieting. Which specific foods are problematic, and why exactly do they cause weight gain?

Many of us struggle with choosing healthy lunch options in a corporate environment, often falling for the myth that 'tasty food has zero calories.' From a conventional medical perspective, most restaurant meals are dense in refined carbohydrates and saturated fats. These cause rapid spikes in blood glucose and insulin levels, signaling the body to store energy as fat rather than burn it. Hidden sugars and excessive sodium further lead to edema (water retention) and a sluggish metabolic rate. In Traditional Korean Medicine (TKM), this process is interpreted as the accumulation of 'Dam-eum' (phlegm-fluid retention) and 'Eo-hyeol' (blood stasis). Dam-eum refers to metabolic waste products formed when fluid metabolism is impaired. Spicy, salty, and stimulating foods damage the function of the Spleen and Stomach (Bi-wi), hindering digestive efficiency and creating an environment where metabolic debris accumulates in the body. When this is coupled with 'Bi-heo' (Spleen Deficiency), where the digestive system is weakened, your overall energy (Qi) drops. This transforms the body into a constitution that swells easily and gains weight even with small portions. Therefore, the core issue with dining out is not the calorie count itself, but how these foods erode your body's innate 'metabolic capacity.' Rather than absolute fasting or completely cutting out social dining, it is far more important to assess your current metabolic state and establish a personalized dietary guide.