How much protein should you eat?

Unlike fat and carbohydrates, protein isn’t used as a primary energy source under normal circumstances. Instead, it’s used to build and maintain muscle and to replenish the amino acid supply used to make enzymes, hormones, and other tissues besides muscle.²

For adults with diabetes, obesity, and other metabolic issues, we recommend eating a low carb diet that is at least moderate in protein. This goes for all levels of carb reduction.
 

Adequate protein intake

We consider adequate protein as roughly 1.2 to 2.0 grams per kilogram (g/kg) of reference body weight per day for adults.³ To maximize your nutrition per calorie, we recommend you aim for the higher end of this range, between 1.6 g/kg and 2.0 g/kg.

Instead of using reference body weight, you can use the chart below to estimate how much protein you should aim for each day. For most people, this is between 90 and 140 grams per day.

Minimum daily protein target

How do you estimate how much protein you are getting in a meal? For most “protein foods,” one ounce equals about 7 grams of protein.

As an example, you can get about 100 grams of protein by eating three eggs and an ounce (30 grams⁴) of cheese at breakfast, 4 to 5 ounces (120 to 150 grams) of fish at lunch, and 5 ounces (140 grams) of meat at dinner. Please see additional ideas for meeting your protein needs in our complete protein guide.

Adequate protein intake has been shown to preserve muscle mass, improve body composition, and provide other health benefits in people who eat low carb diets or higher carb diets.⁵

Although Diet Doctor’s recommendation for minimum protein intake is at least 50% higher than the minimum Recommended Daily Allowance (RDA) for protein of 0.8 g/kg of body weight, it is less than “high protein” diets containing more than 2 g/kg of protein per day.

These higher intake levels may have added benefits when needs are truly increased, such as healing from major injury or surgery, or for increasing muscle mass for competitive body building.⁶ In fact, most people can probably build muscle with a protein intake of 1.6 g/kg/day.⁷

Protein sources

We recommend that you choose unprocessed meat, poultry, seafood, eggs and/or dairy as your main protein sources. Consuming animal products helps ensure that you receive all of the essential amino acids your body needs.⁸

Lacto-ovo vegetarian keto diets are definitely an option, and even vegan low carb diets are possible. However, consistently meeting protein needs can be challenging for vegans who eat very low carb or ketogenic diets as most plant-based proteins are also higher in carbohydrates.⁹

Protein intake per meal

In addition to the daily amount of protein, it’s important to consider the amounts consumed at meals. Because there appears to be a limited amount of protein that can be absorbed at a meal, it may be best to evenly space out your protein throughout the day, if possible.¹⁰

Some people fear that if you eat much more protein than your body can absorb, the resulting excess amino acids may instead be used for gluconeogenesis (literally “making new glucose”) or raise insulin levels.¹¹ However, this has not been shown to be a clinically significant problem in the setting of a low carb diet.¹²

In fact, well-conducted physiological studies show that protein is not a meaningful contributor to blood glucose either in healthy people or people with type 2 diabetes.¹³ One study showed even a meal with 50 grams of protein didn’t cause a significant increase in blood sugar.¹⁴

However, the overall dietary context may matter. One study demonstrated that in people with type 1 diabetes, eating significant amounts of protein without carbs will not affect blood sugars, whereas protein eaten with carbs will result in a higher peak blood glucose than that same amount of carbs without protein.¹⁵ So it is true that protein can raise blood glucose in some settings. However, when following a low carb diet, or in someone who is metabolically healthy, this is likely not a clinical concern.

Summary

For the reasons listed above, we recommend an adequate protein intake of roughly 1.2 to 2.0 grams per kilogram (g/kg) of reference body weight per day for adults, aiming for the upper end of that range for maximum nutrition per calorie. This is higher than the RDA of 0.8g/kg/d but lower than “high protein” intakes above 2.0gm/kg/d.

/ Franziska Spritzler, RD