High Protein Diets

Effects of a high protein diet: Is a high protein diet bad for you?


Protein is the most important macronutrient when trying to build muscle. For people who have a goal of increasing muscle mass, consideration of a high intake of protein is necessary. Many questions have been asked regarding a high protein intake, such as what are the effects? What is considered high protein? Are there any negative effects? In this article, we will be discussing the answers to these questions so that you are well informed about having a high protein diet.

What is considered high protein?

When discussing an adequate protein intake to increase muscle mass, it is good to know what is considered a “high” amount and what is considered “normal”. According to the US recommended daily allowance (RDA), a “normal” amount of protein consumption would be 0.8g/kg/day, and anything over that amount would be considered “high” (2). However, according to a position statement made by The International Society of Sports Nutrition, this amount of protein is not enough to build muscle. They suggest that an adequate amount of protein to consume for individuals who are physically active would be 1.4-2.0g/kg/day, and anything above 2.0g is deemed “high” (2).

Fat loss with a high protein diet

One of the main advantages that a high protein diet can give an individual would be aiding in fat loss. This occurs for many different reasons, one of them being the satiety factor. Satiety means to feel full after eating. Protein is the macronutrient with the highest satiety factor, followed by carbohydrates, and then fats (1). Usually, when people diet or “cut”, it is common for many to feel hungry and want to eat more. This feeling typically discourages people from dieting and can lead to binge eating. A higher protein intake can help with these issues. Due to the high satiety effect of protein, individuals could feel more satisfied, are more inclined to stay on track with their diet, and are less likely to binge. Another way that protein aids in fat loss is through its influence on the thermic effect of food, which is also named diet-induced thermogenesis (DIT). The thermic effect is an increase in metabolic rate (calorie burn). Protein is the highest macronutrient on the DIT scale, followed by carbohydrates, and then fats. (1). Evidence has shown that a higher protein intake increases the thermic effect of food, which in turn, increases resting metabolic rate and energy expenditure. Resting metabolic rate is the calories an individual burns when at rest, such as breathing, digestion, and maintenance of body temperature. Due to protein’s effect in the body to increase energy expenditure and resting metabolic rate, more calories are burned throughout the day inducing greater fat loss (1).

POSSIBLE issues with having high protein

There is a potential issue to consider when consuming a high protein diet, which is an increased acid load to the kidneys in the form of sulfates and phosphates (1). Interventional human studies have shown that a high protein diet increases the risk of a stone formation made of calcium in the urinary tract(1). It is suggested that individuals who go on high protein diets should also include ingesting fruits or vegetables in order to maintain a normal acid balance in the body (1). Consumers of high protein should also be wary of the type of protein they choose to ingest. Various protein-rich foods, such as red meats, are filled with saturated fats and cholesterol which may put individuals at a higher risk of heart disease (1). It is important for consumers to be proactive in making sure they are ingesting enough nutrients to offset these imbalances, but as well, to not be discouraged from going on a high protein diet.

Points to take away

In this article we discussed the pros and potential cons from having a high protein diet. These are the main points of the article that one should take away:

  • The RDA considers protein “high” after ingesting more than 0.8g/kg/day. However, the position statement by the International Society of Sports Nutrition states that anything above 2.0g/kg/day is considered high, as they claim 0.8g/kg/day is not enough to build muscle.
  • High protein intake could help with fat loss due to its satiety factor and the increased thermic effect it has with food.
  • There are possible negative effects to having high protein such as the increased risk of acid buildup in the kidneys, calcium stone formation in the urinary tract, and heart disease.


  1. https://nutritionandmetabolism.biomedcentral.com/articles/10.1186/1743-7075-11-53
  2. https://jissn.biomedcentral.com/articles/10.1186/1550-2783-11-19