Don't eat vegetables, especially leeks and tomatoes. Overnight vegetables will produce a lot of nitrite, which is carcinogenic. The harm of nitrite will turn hemoglobin in blood into methemoglobin, make red blood cells lose their oxygen-carrying function, lead to tissue hypoxia, and lead to poisoning symptoms such as cyanosis of skin and lips, headache, dizziness, nausea and vomiting, palpitation, and even death.