A low protein diet is normally recommended to help treat certain health conditions. Impaired liver function, kidney disease, or disorders that interfere with protein metabolism are some of the more common conditions that may require a low-protein diet.
In recent years, science has also found that low-protein diets can prolong longevity and offer protection against chronic diseases. However, it is important to also know its risks and what foods are allowed.
How does a low protein diet work?
This type of diet requires that we restrict the amount of protein we consume. Normally, it is advised that it constitutes 4 to 8% of the daily calories. This translates to between 20 and 50 grams of protein per day , depending on the amount of calories we consume.
To be able to compare, it is generally recommended that an ordinary person at least 10-15% of their daily calories from protein. This amount can be increased for athletes, older adults, and people with certain health problems.
Protein is vital to health, but reducing protein intake can be therapeutic for people with specific conditions. In particular, low-protein diets can benefit people with decreased liver or kidney function. They may also be necessary for those with disorders that affect protein metabolism, such as homocystinuria and phenylketonuria.
However, following a low-protein diet requires careful planning to prevent health problems and nutritional deficiencies. In addition, there are other risks and possible drawbacks that we must consider before starting such a diet. So it is recommended to go to a specialist to make sure we are well nourished.
Who should follow this diet?
Some people cannot tolerate high levels of protein. If the body cannot process proteins or their debris, these substances build up and cause symptoms ranging from nausea and vomiting to brain damage. For these people, following a low-protein diet will reduce the risk of negative health effects.
Kidney disease
By reducing protein intake, people with kidney disease who are not on dialysis can reduce stress on the kidneys and prevent urea buildup in the bloodstream. The body produces urea, a compound, during the digestion of proteins. In people who do not have kidney problems, urea leaves the body through urine without causing problems.
However, when the kidneys are not working properly, urea builds up in the blood and causes symptoms such as nausea, fatigue, and loss of appetite. Studies show that a very low protein intake can slow the progression of advanced kidney failure.
Diabetic nephropathy
Science has also discovered from studies that a low protein diet can improve the symptoms of diabetic nephropathy, which refers to kidney damage induced by diabetes.
However, he found no adverse effects of the diet, such as worsening of other diabetes symptoms.
Phenylketonuria and homocystinuria
Phenylketonuria is a rare disorder that occurs when the body does not make the enzyme necessary to break down an amino acid called phenylalanine. Amino acids are the building blocks of proteins. For a person who has this disease, eating foods rich in protein can cause phenylalanine to build up in the body.
Left untreated, these people can lead to intellectual disability and other neurological symptoms, such as hyperactivity, lack of coordination, and seizures. The main treatment is a very low protein diet for life. People with the condition should consume only the minimum amount of phenylalanine necessary for healthy growth and development.
Homocystinuria is an inherited disorder that affects the body’s ability to process methionine, another amino acid. A buildup of methionine causes problems with vision and bone health. Treatment also involves a very low protein diet.
Allowed foods
Fresh fruit and most vegetables can play an important role in a low-protein diet. Replacing some meat with vegetables and grains is an effective way to reduce your protein intake. Vegetables and grains should form the main body of meals, with a supplemental protein source.
A person on a low protein diet can get most of their calories from the following foods, which are relatively low in protein.
Low in protein
The following are low protein foods:
- All fruits except dried fruits
- All vegetables except peas, beans, and corn
- Many sources of healthy fats, such as olive oil and avocados
- Herbs and spices
There are other types of foods that are low in protein and that a person should be cautious when incorporating them into the diet. Some of these foods include sugar, candies without gelatin, tea and coffee, without cow’s milk, jams and jellies, mayonnaise, and many sauces and dressings, including tomato sauces and salad dressings.
Moderate in protein
On a low protein diet, people should eat foods that contain moderate amounts of protein in moderation. Some examples are:
- Bread
- Cereals
- Pasta
- Oatmeal
- Corn
- Rice
Low-protein versions of many of these products are available online, at health food stores, or at drugstores. Plant-based proteins and meat can be included in the diet, but should be used as garnishes and consumed only in small amounts. You may also need to increase your intake of healthy fats, which can provide additional calories to help meet daily needs.
Foods to Avoid
Protein is still a necessary part of the diet, even if we follow a low-protein diet. So it’s not about avoiding it entirely. However, if we follow a low-protein diet, we must consume protein-rich foods such as animal products and plant-based proteins in moderation.
To do this, you have to increase your intake of healthy low-protein foods such as fruits and vegetables. At the same time, we may need to reduce protein portion sizes. For example, a serving of chicken generally weighs around 113 grams. On a low-protein diet, we may need to cut that amount in half and stick to 57 grams to keep protein intake in check.
Protein-rich foods that should be limited or avoided include:
- Meats such as chicken, turkey, beef, and pork
- Fish and shellfish
- Eggs
- Legumes, including beans, peas, and lentils.
- Dairy products like milk, cheese, and yogurt.
- Soy products like tofu and tempeh.
- Nuts like walnuts, almonds, and pistachios.
- Seeds like chia seeds, flax seeds, and hemp seeds.
Benefits of a low protein diet
The positive effects of a low-protein diet apply primarily to people with specific conditions or diseases, rather than those who are generally healthy. The liver normally breaks down excess protein, producing a waste product called urea, which is excreted by the kidneys. Decreasing protein intake can ease the workload on the liver and kidneys, which can be beneficial for people with liver disease or kidney failure.
This helps improve protein metabolism and prevents urea buildup in the bloodstream. Having high levels of urea in the blood causes symptoms such as fatigue, loss of appetite, weight loss, and changes in mental state. It can also be associated with an increased risk of type 2 diabetes and death in people with heart failure.
Reducing protein intake is also necessary for those with genetic disorders that affect protein metabolism, such as homocystinuria and phenylketonuria. These disorders alter the breakdown of specific amino acids, so reducing your intake of this macronutrient can help minimize symptoms.
Studies indicate that a low-protein, high-carbohydrate diet can help protect brain health and reduce cognitive decline . However, the scientists only conducted this research in mice and cannot be sure of the effects in humans.
Side effects
Protein is an essential nutrient crucial for growth and development. The body uses it to form the foundation of muscles, skin, and bones, produce important enzymes and hormones, and build and repair tissue.
Studies show that a protein deficiency can have detrimental health effects, including impaired immune function, loss of muscle mass, and decreased growth. Other possible symptoms of a protein deficiency include bloating, anemia, fatty liver disease, hair loss, and reduced bone density.
In addition to the potential health risks involved, decreasing your protein intake can be a big challenge. Following a low-protein diet not only requires dietary monitoring, it also requires careful planning to make sure your other nutritional needs are met . This is because high-protein foods provide a good amount of calories and key micronutrients.
For example, beef is rich in B vitamins, iron, and zinc, while beans are a good source of magnesium, phosphorus, and potassium. When following a low protein diet, it is important to make sure you get these nutrients from other sources to prevent nutrient deficiencies. Therefore, it is important to follow the advice of a professional and accept the follow-up of a nutritionist.
