Urinary protein 2 and ten dietary taboos

Don’t blindly supplement high-protein foods, strictly control your daily salt intake within 3g, and resolutely avoid foods that are known to damage the kidneys. The remaining so-called “taboos” must be adjusted based on your kidney function, primary disease, and comorbidities. There is no “one-size-fits-all” list that is universal across the Internet.

The first pitfall that many people fall into is to simply give up all protein based on what is said on the Internet. Last month I treated a 32-year-old patient with IgA nephropathy. His urine protein was just 2+. He stopped eating eggs and milk when he got home. He didn't even dare to touch lean meat. He came back for a checkup half a month later and found that the urine protein did not drop much, but his serum albumin dropped by 2g. He was so hungry that his face was sallow and his muscles were thin, and he couldn't even climb two floors until he was out of breath. Regarding the issue of protein intake, there has actually been a change of opinion in the academic community: in the early years, the traditional thinking was a strict low-protein diet, which required protein intake of no more than 0.6g per kilogram of body weight per day to minimize the metabolic burden on the kidneys. ； However, in recent years, the latest KDIGO guidelines have adjusted the standards. As long as the kidney function has not reached stage 3 and there is no obvious increase in creatinine, a protein intake of 0.8-1.0g per kilogram of body weight per day is more secure and can prevent malnutrition from dragging down the immunity. Take a 60-kg adult as an example. One egg, one 250ml bag of pure milk, and one or two lean pork or chicken every day is just enough protein. There is no need to supplement more or to give up completely.

What is more important than protein control, but also more easily overlooked, is salt control. 3g of salt is only the amount of a beer bottle cap. Many people think that if they add less salt in their cooking, they meet the standard. In fact, the pitfalls of invisible salt are hard to prevent. There used to be a retired aunt who was very strict about salt in cooking, but every morning she had to eat white porridge with pickled mustard and two pieces of soybean curd with rice at night. Her blood pressure fluctuated around 140/90 all year round. She couldn't keep it down even after taking more antihypertensive medicine, and her urine protein fluctuated. Later, she stopped all these pickled products and checked again after half a month. The urine protein dropped by a plus sign. In addition to pickles and cured meats, there is also a lot of sodium added to take-out, processed snacks, and even many sweet breads and soda crackers. These must be included in the total daily salt intake.

There is also a minefield that you should not touch. It does not matter what kind of kidney disease you have. As long as you have kidney damage, you should avoid it. For example, immature star fruit contains neurotoxins that people with renal insufficiency cannot metabolize. Eating it can easily aggravate kidney damage. ； There are also unknown folk remedies and ancestral secret recipes that claim to "tonify the kidneys". Many of them contain aristolochic acids, which can cause irreversible damage to the kidneys. I have seen several patients who originally only had mild proteinuria suffer from acute renal failure after eating random folk remedies. Oh, by the way, if in addition to urinary protein 2+, you also have the problem of high uric acid, you should avoid high-purine seafood, animal offal, and rich broth. If you have diabetes, your priority for sugar control may even be higher than protein control.

As for the most frequently asked question, "Can we eat soy products?", in fact, the views of academic circles have changed over the years. In the past, everyone thought that plant protein was a "low-quality protein" and that excessive metabolic waste would increase the burden on the kidneys. Now it has been proven that the amino acid pattern of soy protein is almost the same as that of animal protein, and it is a high-quality protein. As long as you control the total protein intake throughout the day, drink a cup of soy milk and eat a piece of tofu occasionally, it is even healthier than eating too much red meat, and you don't need to be beaten to death with a stick.

To be honest, I have seen too many patients who are more nervous about diet control than taking medicine. They dare not eat this or touch that. In the end, their nutrition cannot keep up, their immunity is weakened, and they are prone to infection and higher urinary protein. The gain is not worth the loss. To put it bluntly, diet is just a part of auxiliary control. Don’t treat it as a scourge. If you are really unsure, ask your attending doctor during your next review. It is much more reliable than relying on the general list on the Internet.