Protein farts refer to excessive or smelly farts that a person may experience on a protein-rich diet. While many people may attribute the gas to protein, there is no evidence to support this. While some proteins may worsen the smell, an increase in flatulence may instead be due to nonprotein components such as sugars, starches, and fiber.

Some people may believe that eating more protein can increase flatulence. However, the existing scientific literature suggests a more nuanced picture. While consuming certain proteins can influence the smell of gas, any increases in flatulence are more likely due to foods containing carbohydrates that are difficult for bacteria in the gut to break down.

In this article, we will discuss how protein-rich diets may impact flatulence and provide some tips to help reduce the volume and smell of gas.

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While there is anecdotal evidence to suggest that eating a high protein diet can increase flatulence, there is limited scientific research to support these claims. Instead, it may be the case that people attribute increased flatulence to certain dietary elements.

For example, evidence notes that foods containing certain sugars, starches, and fiber can all contribute to an increase in gas. Many of these dietary components may be present in foods people include on a high protein diet, such as legumes, vegetables, and dairy products. Similarly, whey or casein protein supplements may also contain high amounts of lactose.

A 2020 study investigated the effects of different diets on bloating. The results suggest that a high fiber diet rich in protein may result in increased bloating. However, the authors note that this diet was high in plant-based proteins, such as beans, nuts, and wheat, which many believe cause flatulence.

While most evidence suggests other elements may contribute to the volume, some research suggests that certain proteins may affect the smell of gas. For example, cysteine is a sulfur-containing amino acid that is commonly present in many protein sources. When bacteria in the gut break this amino acid down, it may produce hydrogen sulfide, which is a pungent-smelling gas.

The average person will pass gas multiple times per day, with some sources noting they may pass wind up to 25 times a day.

While passing gas is typical, an individual can attempt to reduce large amounts of flatus by altering their diet and limiting certain foods that commonly cause flatulence. This can include reducing the intake of:

  • dairy products
  • dried fruit
  • fruit
  • foods high in insoluble fiber
  • legumes
  • certain vegetables

A person may also consider eating smaller meals more often while taking their time to chew food and taking sips rather than large gulps of drinks. It may also be beneficial to exercise regularly, as this can help improve digestion.

Additionally, people may consider changing protein supplements that contain less sugar. A person may also add certain herbs to their diet, which may reduce gas and bloating, as well as over-the-counter remedies, such as activated charcoal, which may also help reduce gas.

Learn more about home remedies to help reduce flatulence.

According to the Food and Drug Administration (FDA), it is advisable that adults consume 50 grams (g) of protein a day, as part of a 2,000-calorie diet. However, they note that a person’s daily value may differ depending on their calorie needs. A 2017 paper suggests that people may want to aim for 0.8 to 1.2 g of protein, per kilogram of body weight, per day.

Many factors can affect how much protein a person requires, such as their activity level, weight, height, and whether they are pregnant. Other variables may include the profile of amino acids available in certain protein sources and the digestibility of individual amino acids.

The Dietary Guidelines for Americans 2020–2025 provides the following Recommended Daily Allowance (RDA) for protein by sex and age group:

AgeProtein RDA
child aged 1–313 g
child aged 4–819 g
child aged 9–1334 g
female teenager aged 14–1846 g
male teenager aged 14–1852 g
female adult aged 19+46 g
male adult aged 19+56 g

Additionally, the Department of Agriculture provides a calculator to help people work out how much protein and other nutrients they may require.

If an individual notices significant increases in flatulence after eating protein, this may indicate a food intolerance. As well as an increase in flatus, a person may notice other symptoms such as bloating, abdominal pain, and diarrhea. For example, someone may experience a protein intolerance or lactose intolerance.

Doctors can typically treat an intolerance by first determining which food items someone is intolerant toward. They can then help construct a diet plan that minimizes or eliminates these undesirable foods.

There is little scientific research to suggest high protein diets may cause someone to experience greater flatulence. Instead, an increase in flatus may be due to the diet including more carbs that can increase gas. However, other evidence notes that digesting certain proteins may cause farts to have a more pungent smell.

If a person notices other abdominal symptoms, such as pain, bloating, and diarrhea, this may indicate a potential intolerance to certain foods. It may be advisable to identify the causative foods and try to reduce or eliminate them from the diet.