To be honest, when I was younger, I tried the same route—eating only chicken breast and sweet potatoes to lose weight quickly—and I ended up feeling dizzy and exhausted very easily. There are definite advantages to a chicken breast diet. Being high in protein, it prevents muscle loss and provides long-lasting satiety, which is great for curbing 'false hunger.' The simplicity of preparation is also a major merit. However, there are clear downsides. Excessive protein intake can strain the liver and kidneys, but the primary concern is 'digestion.' In Traditional Korean Medicine, we refer to this as 'Spleen Deficiency' (Bi-heo, 脾虛). If you continuously consume tough proteins while your Spleen function is weak, it puts a burden on the gastrointestinal tract and often leads to abdominal gas. Specifically, those prone to swelling may experience an increase in 'Phlegm-Fluid' (Dam-eum, 痰飮), a phenomenon where metabolic waste accumulates in the body. If your diet is too restrictive while you are in a state of 'Blood Stasis' (Eo-hyeol, 瘀血)—where blood circulation is sluggish—your overall metabolism may actually slow down further. Ultimately, the answer is 'it depends on the individual.' I recommend it for those with strong digestion and high activity levels, but for those with low energy and slow digestion, it can actually be detrimental. The healthiest path to avoiding the yo-yo effect is to first assess your body's condition and then build a balanced diet accordingly. Let's figure out the best plan for your specific constitution.