What are side effects of too much protein?

In this brief article we will answer the query,” What are the side effects of too much protein?” We will look at the recommended dietary allowances of proteins for different age groups and genders. We will briefly discuss the risks of consuming too much protein.

What are side effects of too much protein?

Eating too much protein can result in undesirable side effects such as an increase in weight, poor breath, having constipation, diarrhea, dehydration, damage to the kidney, high risk of cancer, high risk of heart disease and calcium. We will look at this in depth, but first let’s find out what is the recommended dietary intake of protein.

What is the Recommended Dietary Allowance of protein?

The Recommended Dietary Allowance (RDA) is as below for people at different age groups;

Life stage and genderRDA in grams (g) per day
Infants and children
0-6 months9.1
6-12 months11.0
1-3 years13.0
4-8 years19.0
9-13 years34.0
14-18 years52.0
19-70 years and older56.0
9-13 years34.0
14-70 years and older46.0
Pregnant or breastfeeding women
All ages71.0

What are the risks of eating too much protein?

Weight gain

High protein foods usually assist with weight loss although such kind of weight loss is usually short term. Consumption of excess protein is usually stored as fat and the excess amino acids are usually excreted. 

The storage of the excess protein as fat can result in weight gain over time more so if you consume a lot of calories and you are still increasing your protein intake.

Bad breath

Consumption of large amounts of protein can result in bad breath more so if you restrict your carbs intake. In a survey that was done, 40% of the participants reported having bad breath and this could be a result of the body going into ketosis which gives out chemicals that have an unpleasant fruity smell.

Doing stuff like brushing and flossing doesn’t remove the smell but to alleviate it you can increase your water intake and brush more often or chew gum to counter the effect.


In the same research, 44 percent of participants reported to have constipation. Diets that are high in proteins and restrict carbs tend to be low in fiber.

Increasing your water intake and dietary fiber can assist in reduction of constipation. You should also make sure to track your bowel movements.


Consumption of too much dairy or processed foods together with a diet that is low in dietary fiber can result in diarrhea. This is exacerbated if you are lactose intolerant or consume protein sources such as fried meat, fish and poultry. It is recommended that you consume heart-healthy proteins instead.

To alleviate or prevent diarrhea, take plenty of water and steer clear of caffeinated beverages, reduce your intake of fried foods and lots of fat and also boost your consumption of fiber.

Kidney damage

Consumption of excess protein can also result in damage to the kidney in people with preexisting kidney disease. This is attributed to the excess nitrogen which is found in the amino acids that build the proteins.

When the kidneys get damaged they have to work extra hard to remove the extra nitrogen and the waste products of protein metabolism

Increased cancer risk

Research has shown that some high protein diets especially in red meats increase the risk of various health issues such as cancer. Consumption of more red or processed meat is linked with some types of cancers such as prostate cancer. 

Consumption of protein from other sources has also been linked with a low risk of cancer. 

Heart disease

Consumption of a lot of red meat and dairy products that have a lot of fat can also result in heart disease. This could be as a result of increased intake of cholesterol or saturated fats.

According to one study done in 2010, consumption of high amounts of red meats and high fat dairy products increased the risk of heart disease in females. Consumption of protein sources such as poultry, fish and nuts were found to lower such risk.


In this brief blog we have addressed the query,” What are the side effects of too much protein?” We have looked at the recommended dietary allowances of proteins for different age groups and genders. We have briefly discussed the risks of consuming too much protein.



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