From a nutritional and biochemical perspective, the most harmful foods are those that provide calories with no nutritional value, contain harmful additives, and negatively impact metabolism. Ultra-processed foods, which are loaded with refined sugars, trans fats, and chemical additives (such as soda, fast food, and processed snacks), are particularly harmful. They are associated with inflammation, insulin resistance, and cardiovascular disease. Similarly, processed meats such as cold cuts and sausages contain nitrates and nitrites, which are associated with a higher risk of cancer. Finally, refined vegetable oils that are high in omega-6s disrupt the body’s inflammatory balance. It is crucial to avoid these foods and favor a natural, nutrient-rich diet consisting primarily of minimally processed foods.