By Carol Ann Head, MS, RDN 

We’ve all lived through the low-carb crazes and the fat-free phases, but protein seems to be the one macronutrient where pumping up rather than pulling back is encouraged. But is it possible to eat too much protein? How much is too much? 

The three major macronutrients — fat, carbohydrate, and protein — are all essential for normal growth and development. Current guidelines suggest the following ratios of energy from each macronutrient: 

  • CARBOHYDRATE: 45-65%
  • PROTEIN: 10-35%
  • FAT: 20-35% 

Some people may be surprised to find that of these three building blocks, protein accounts for the smallest percentage of our needs. Beyond building and maintaining skeletal muscle, proteins in the body serve as enzymes, hormones, antibodies, catalysts for biochemical reactions, and more. While protein is essential in the diet, more isn’t always better. 

How much protein do we need? 

The RDA, or recommended daily allowance, tells us the bare minimum needed to prevent disease and malnutrition for the majority of the population. The RDA of protein for adults is 0.8 grams/kilogram of body weight. For a 150-lb. person, that’s 55 grams of protein per day. Translated into food, that’s about the same amount of protein found in an 8-ounce steak. 

Getting more than the bare minimum for protein can have benefits! Aiming for closer to 1.2 grams/kilogram can make it easier to get adequate energy and create balanced meals. A range we often use when guiding meal structure and portions are 20-30 grams per meal, filling in the gaps at snacks. Translated to food, aim to fill 1/4-1/3 of your plate with protein-rich foods like meats, poultry, fish, eggs, Greek yogurt, tofu, tempeh, or beans. Those engaging in regular strength training benefit from higher protein content to support muscle growth. Additionally, older adults have increased protein needs because natural aging makes it harder to maintain muscle. 

Though many Americans load up on protein at lunch or dinner, research suggests that spreading protein intake throughout the day may increase overall absorption. Make sure to incorporate protein into your breakfast and morning snack to boost satiety, too. 

Certain groups have even higher protein needs, in some cases up to 1.8 grams/ kilogram. For athletes, working muscle needs more protein to support muscle repair and regrowth. Those who are sick also may need increased protein. During illness, our body burns energy at a higher rate. Being sick can also lead to decreased appetite. Eating less food and burning more energy means that our bodies will break down our muscles to get energy for physiological processes. 

Consuming protein in amounts above those outlined above is not supported by research and may even have some drawbacks. 

Why do people eat more protein than recommended? 

  1. MUSCLE GAIN: Studies have shown that increases in protein intake aid in muscle growth when consumed alongside resistance training. There is a range in what is recommended from these types of studies, but most find that there is no further benefit in increased protein consumption beyond about 1.8 grams/ kilogram of body weight. For a person who is not strength training, increases in protein beyond maintenance do not contribute to an increase in muscle strength or size. 
  2. DIET RULES: Of the three macronutrients, protein is the only one relatively safe from scrutiny. Protein foods are seen as essential, but fats and carbohydrates are not (even though they are!). Diet programs allow for greater or unlimited amounts of “good” foods, like grilled chicken and other lean meats, through points or special color codes, which can lead to less balance and satisfaction with eating. Additionally, this type of labeling creates associations with foods that are false and ultimately damaging to a person’s health and long-term relationship with food. 
  3. WEIGHT LOSS: Many weight loss programs pair increases in protein intake with decreases in carbohydrates. High protein intake can help preserve muscle when energy is restricted. While this is a beneficial effect, it is important to keep in mind that when weight is regained after a diet, muscle is not regained proportionally. Over time, dieting and weight cycling lead to both loss of lean body tissue and overall weight gain. 

What’s the harm in too much protein? 

  • DISRUPTED BALANCE: When protein accounts for a large part of an individual’s overall eating pattern, the balance between other essential nutrients will likely be negatively impacted. For example, low carbohydrate intake can lead to irritability or fatigue, and lack of fiber can lead to constipation. 
  • RENAL DYSFUNCTION: While most randomized controlled trials do not show that high protein intake leads to renal (kidney) disease, those who already have kidney disease can experience further functional decline. High protein intake has also been linked to an increased risk of developing kidney stones. 
  • METABOLIC CONSEQUENCES: Several studies have shown that high protein intake leads to higher levels of urea and nitrogenous waste, which may increase oxidative stress and inflammation. 
  • INCREASED RISK OF TYPE 2 DIABETES: Population studies show an increased risk for insulin resistance and type 2 diabetes with increased protein intake. Protein ingestion also increases the secretion of glucagon and insulin while decreasing insulin action, which may be a mechanism for the increased diabetes risk. 
  • UNREALISTIC + UNNECESSARY = FRUSTRATING: Trying to reach high-protein goals may prove challenging and unsustainable in terms of planning, preparing, and chewing! Adherence to a strict protein-packed regimen with reliance on protein supplements to meet goals beyond what research supports may lead to unnecessary frustration. 
  • FINANCIAL BURDEN: High-protein foods, especially animal products and protein supplements, are typically more expensive than low- or non-protein foods. 

Placing high importance on protein above other nutrients may cause unnecessary stress for nonexistent gains. Still not sure how protein fits into your current routine? Reach out to Memphis Nutrition Group to reach your sports nutrition goals or to find balance in your relationship with food. 

Carol Ann Head, MS, RDN is a Nutrition Therapist at Memphis Nutrition Group, a nutrition and lifestyle counseling practice offering in-person and virtual nutrition therapy specializing in a non-diet, weight-neutral approach. Contact Memphis Nutrition Group at 901.343.6146 or visit for more information.