By Aayushi Gupta
Published Jul 04, 2025
A high-protein diet is quite popular among people trying to lose weight or build muscle. But eating too much protein for a long time can have side effects that you shouldn’t ignore. Here are 10 possible side effects of a high-protein diet.
Many people think eating lots of protein helps lose weight, but too much of it can lead to extra calories. This can make you gain fat instead of building muscle, especially if you do not exercise.
Weight Gain
High-protein diets often have less fibre because you eat fewer fruits, vegetables, and grains. This can slow down your digestion and cause constipation.
Constipation
Too much protein, especially from meat or dairy, can cause bloating, diarrhea, nausea, or stomach pain. This happens because your gut has to work extra hard to digest all that protein.
Gastrointestinal Discomfort
Eating a lot of protein can make your kidneys release more water to get rid of extra nitrogen. This can dehydrate you if you do not drink enough fluids.
Dehydration
A high-protein diet can stress your kidneys over time. It may worsen kidney function in people who already have kidney disease.
Kidney Problems
If you have liver problems, too much protein can be hard for your liver to process. It may make liver damage worse in some cases.
Liver Issues
When your body breaks down protein for energy, it can produce ketones that cause foul-smelling breath. This is common in low-carb, high-protein diets.
Bad Breath
Focusing too much on protein means you might miss out on other important nutrients. Lack of fibre, vitamins, and minerals can affect your overall health.
Nutrient Imbalance
As per Harvard Health Publishing, eating a high-protein diet that contains red or processed meat may increase the risk of certain cancers. So, it is better to get protein from a mix of plant and lean animal sources.
Cancer Risk