What Happens to Your Body When You Eat Too Much Protein

Protein is one of three macronutrients, which are nutrients your body needs in large amounts on a daily basis. Protein is broken down into amino acids, which are required for critical processes like muscle growth, hormone and neurotransmitter synthesis, and immune function. 

While protein is essential for health and high-protein diets offer several health benefits, some people may go overboard when it comes to their protein intake and take in more protein than their body needs. 

Read on to learn how eating large amounts of protein impacts the body and if it’s possible to eat too much protein. 

Young man and woman sitting at table with barbecue food


Risks of Eating Too Much Protein

Protein can be found in both plant and animal-based foods, such as legumes, chicken, eggs, nuts, and grains. For this reason, people following omnivorous and plant-based diets have plenty of protein-rich foods to choose from.

In the U.S., most healthy adults consume adequate protein, but certain populations, such as older adults and people following restrictive diets, are more at risk for protein insufficiency.

However, some people do consume more protein than their body requires. Although the body can thrive on a higher-protein diet, most people don’t need to take in very large quantities of protein at every meal. That said, studies haven’t found a strong association between high total dietary protein intake and adverse health outcomes.

For example, a 2022 study of 1,639 adults found no significant association between total protein and animal protein intake and the incidence of chronic kidney disease (CKD).

What’s more, studies show that very high protein intakes of over 3 grams per kg (g/kg) (1.36 grams per pound (g/lb)) per day for prolonged periods are not associated with harmful side effects in healthy adults.

High Red and Processed Meat Intake May Harm Health

The source of your protein matters. Although consuming a diet high in total protein hasn’t been associated with health risks, diets high in certain protein types, such as red and processed meats, are strongly linked to adverse health outcomes.  

Studies show that people who follow diets high in red and processed meats are at a higher risk for developing several health conditions, including a CKD, a number of cancers, and heart disease.

Compounds formed when cooking red meat, such as polycyclic aromatic hydrocarbons (PAHs), heterocyclic amines (HCAs), and heme iron found in red meat, promote inflammation and changes to your DNA, which enhance the development of cancer. What’s more, ​​metabolites formed during the digestion of red meat, such as trimethylamine N-oxide, may be associated with higher risks of heart disease, CKD, and type 2 diabetes.

The American Heart Association (AHA) recommend decreasing the intake of red and processed meats and increasing sources of plant-based proteins like beans and seeds which may protect against chronic diseases like heart disease.

Other Potential Side Effects

If your diet isn’t well-balanced, or if you’re consuming more calories from protein than your body needs, it could lead to the following side effects:

  • Constipation: If your diet is very high in animal-based protein and low in fiber-rich plant foods like fruits and vegetables, you might experience constipation and other digestive symptoms like bloating.  
  • Weight gain: Over-consuming calories, meaning you’re taking in more calories than your body burns on a daily basis, will cause you to gain weight. Although high-protein diets have been shown to be effective for weight loss, consuming too many calories in general, no matter the source, can cause you to gain weight. 
  • Malnourishment: Protein is the most filling macronutrient, so eating excessive amounts of protein may interfere with your intake of other nutritious foods such as fruits and vegetables. To ensure you’re eating a balanced diet that contains all the nutrients your body needs, it’s best to consume balanced meals that provide a source of protein, fiber-rich carbs, and healthy fats. 

In some cases, protein may need to be limited in order to manage a health condition. For example, people with advanced kidney disease often have to follow lower protein diets to preserve their kidney function. 

How Much Protein Should You Eat in a Day?

A person’s daily protein requirement depends on several factors, including their age, gender, body weight, body composition goals, and physical activity levels. 

The recommended dietary allowance (RDA) for protein is currently set at 0.8 g/kg of body weight (0.36 g/lb) per day. However, even though many people think the RDA is the optimal amount of protein for adults, it’s actually the minimum intake necessary to meet basic protein requirements and prevent muscle loss in most people.

While the RDA may be appropriate for sedentary people, experts argue that physically active adults require much more protein than the RDA to promote optimal health. According to experts, daily protein requirements for active adults fall between 1.2-2.0 g/kg (0.54-0.9 g/lb).

Most active adults should be able to take in optimal protein simply by adding one or more plant- or animal-based protein sources to each meal and snack. 

Keep in mind that certain populations, such as older adults, athletes, pregnant and breastfeeding people, and people with medical conditions like cancer, require more protein than the general population.

Children and teens also have higher protein needs than the average adult. This is because kids need to take in more protein in order to support growth and development. Like adults, more active children and teens, like teen athletes, require more protein than sedentary kids.

Adults and kids with higher protein needs need to pay extra attention to the composition of their meals and snacks and may need to add in protein supplements, such as protein powder, to meet their needs. 

When To See Your Healthcare Provider

Most healthy adults shouldn’t have an issue meeting their protein requirements. However, if you’re following a restrictive diet that cuts out many high-protein foods, like a vegan diet, or if you have a medical condition that increases your need for protein, you may want to work with a healthcare provider like a registered dietitian to ensure you’re taking in enough protein to support overall health.

Additionally, if you have a health condition that requires protein restriction, like advanced kidney disease, your healthcare provider can provide you with protein intake goals in order to keep you healthy.

If you’re concerned that you’re taking in too much protein, a healthcare provider can determine your protein requirements based on factors like your gender and activity and review your dietary intake to see if your current protein intake is excessive.

Frequently Asked Questions

  • What happens if you take too much protein powder?

    Protein powder can be an effective tool for increasing your protein intake, but certain ingredients found in protein powder can cause side effects if you consume too much. For example, protein powders can contain lactose and sugar alcohols, both of which can cause digestive issues like gas and bloating in some people. If you do depend on protein powder to meet your protein needs, it’s a good idea to limit yourself to one to two servings per day to leave room for other nutritious options, like meals and snacks made with whole foods.

  • Does eating too much protein cause weight gain?

    Eating too many calories in general can cause you to put on weight. When you’re taking in more calories than you burn on a daily basis, it creates a calorie surplus, which leads to weight gain. However, high-protein diets can be effective for weight loss as long as you’re consuming the right amount of calories for your specific health goals. 

  • Do some people need to limit their protein intake?

    In some cases, protein intake needs to be limited in order to control an underlying health condition. People with medical conditions like advanced kidney disease and phenylketonuria need to follow low-protein diets in order to prevent medical complications. On the other hand, medical conditions like cancer can significantly increase a person’s need for protein.

Was this page helpful?
14 Sources
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Hengeveld LM, Boer JMA, Gaudreau P, et al. Prevalence of protein intake below recommended in community‐dwelling older adults: a meta‐analysis across cohorts from the PROMISS consortiumJ Cachexia Sarcopenia Muscle. 2020;11(5):1212-1222. doi: 10.1002/jcsm.12580

  2. Alvirdizadeh S, Yuzbashian E, Mirmiran P, Eghtesadi S, Azizi F. A prospective study on total protein, plant protein and animal protein in relation to the risk of incident chronic kidney diseaseBMC Nephrol. 2020;21:489. doi: 10.1186/s12882-020-02079-y

  3. Antonio J, Ellerbroek A, Silver T, et al. A high protein diet has no harmful effects: a one-year crossover study in resistance-trained malesJ Nutr Metab. 2016;2016:9104792. doi: 10.1155/2016/9104792

  4. Papier K, Knuppel A, Syam N, Jebb SA, Key TJ. Meat consumption and risk of ischemic heart disease: A systematic review and meta-analysisCrit Rev Food Sci Nutr. 2023;63(3):426-437. doi: 10.1080/10408398.2021.1949575

  5. Mirmiran P, Yuzbashian E, Aghayan M, Mahdavi M, Asghari G, Azizi F. A prospective study of dietary meat intake and risk of incident chronic kidney diseaseJ Ren Nutr. 2020;30(2):111-118. doi: 10.1053/j.jrn.2019.06.008

  6. Farvid MS, Sidahmed E, Spence ND, Mante Angua K, Rosner BA, Barnett JB. Consumption of red meat and processed meat and cancer incidence: a systematic review and meta-analysis of prospective studiesEur J Epidemiol. 2021;36(9):937-951. doi: 10.1007/s10654-021-00741-9

  7. Wang M, Wang Z, Lee Y, et al. Dietary meat, trimethylamine n-oxide-related metabolites, and incident cardiovascular disease among older adults: the cardiovascular health studyATVB. 2022;42(9). doi: 10.1161/ATVBAHA.121.316533

  8. Rollet M, Bohn T, Vahid F. Association between dietary factors and constipation in adults living in luxembourg and taking part in the oriscav-lux 2 surveyNutrients. 2021;14(1):122. doi: 10.3390/nu14010122

  9. Romieu I, Dossus L, Barquera S, et al. Energy balance and obesity: what are the main drivers? Cancer Causes Control. 2017;28(3):247-258. doi: 10.1007/s10552-017-0869-z

  10. Carbone JW, Pasiakos SM. Dietary protein and muscle mass: translating science to application and health benefitNutrients. 2019;11(5):1136.  doi: 10.3390/nu11051136

  11. Bandegan A, Courtney-Martin G, Rafii M, Pencharz PB, Lemon PWR. Indicator amino acid oxidation protein requirement estimate in endurance-trained men 24 h postexercise exceeds both the EAR and current athlete guidelinesAm J Physiol Endocrinol Metab. 2019;316(5):E741-E748. doi: 10.1152/ajpendo.00174.2018

  12. Stephens TV, Payne M, Ball RO, Pencharz PB, Elango R. Protein requirements of healthy pregnant women during early and late gestation are higher than current recommendationsJ Nutr. 2015;145(1):73-78. doi: 10.3945/jn.114.198622

  13. Tanaka K, Nakamura S, Narimatsu H. Nutritional approach to cancer cachexia: a proposal for dietitiansNutrients. 2022;14(2):345. doi: 10.3390/nu14020345

  14. Hudson JL, Baum JI, Diaz EC, Børsheim E. Dietary protein requirements in children: methods for considerationNutrients. 2021;13(5):1554. doi: 10.3390/nu13051554

Related Articles