Protein is a macronutrient (aka “macro") essential for total-body health. While we often associate this nutrient with building muscle, protein is essential for regulating numerous physiological functions in the body such as supporting bone health and carrying oxygen in your blood. That’s why it’s so important to meet your protein goals every day.
Getting enough protein is especially important for active people, those wanting to improve their metabolic health, and everyone as we age. Protein intake is essential to build and maintain muscle mass, and increased dietary protein intake earlier in life may help mitigate muscle loss from ageing.
While the exact amount of protein you need per day depends on your age, weight, activity level, and other factors, there are some general protein guidelines that work for most adults to support optimal health and well-being.
Here, find out how much protein you need per day to stay healthy, and why the recommended daily amount is usually not enough.
Why do we need protein?
Proteins are molecules made up of amino acids that are essential for the human body’s structure and function. These amino acids help build DNA synthesis, muscle repair, bone support, muscle contractions, and cell signalling — all functions that keep us alive and healthy. (1)
Protein also helps support our immunity. For example, antibodies are blood proteins that help us fight off infections. (2) The proteins keratin, collagen, and elastin help support our hair, skin, and nails. Most of the protein in our bodies is found in the muscles, skin, and blood. Eating protein foods supplies our body with the amino acids needed to carry out important functions and to support our health.
What is the recommended protein intake for adults?
Given all the vital health benefits of protein, it’s important to get enough of this macronutrient in the daily diet. Not only that, but protein also provides us with energy: Each gram of protein contains 4 calories.
The recommended intake for protein depends on certain factors such as your weight, age, activity level, life stage (such as pregnancy), and other goals, like losing body fat and building muscle. The Reference Nutrient Intake (RNI), or daily recommended amount of protein set by the government, is 0.75 grams of protein for every kilogram of bodyweight. With these guidelines, adult women need at least 45 grams of protein per day while adult men need at minimum 55 grams of protein each day. (3)
However, it’s important to note that the RNI is the absolute minimum recommended amount of protein people should consume daily to support life functions and to prevent nutrient deficiencies.
In reality, the most up-to-date scientific evidence on dietary protein shows that daily protein intake should be much higher than the RNI for optimal health and well-being. Lingo’s Director of Medical Affairs and Clinical Research Jim McCarter, MD, PhD, recommends adults eat about 1.5 grams of protein per kilogram of desired bodyweight. If your ideal bodyweight is 68 kg (about 150 lbs), that means 102 g of protein per day. To reach this amount, aim for at least 30 g of protein at each meal and 15-30 g of protein with snacks.
To hit this protein target, a typical day of eating could look like (highlighting protein foods only):
- Breakfast: Scramble with two whole eggs + 126 g liquid egg whites (26 grams protein)
- Snack: 57 g beef jerky (19 grams protein)
- Lunch: 114 g ground turkey (30 grams protein)
- Dinner: 114 g salmon (30 grams protein)
- Daily total: 105 grams of protein
Is more protein better?
As mentioned, eating more protein than the RNI of 0.75 grams per kilogram of bodyweight is recommended for most adults. Eating more protein can help you build and maintain lean muscle and aid in weight loss. Protein is the most satiating macronutrient compared to carbs and fats, and it helps curb cravings and keep you fuller for longer, partly by helping stabilise blood glucose levels. (4)
You can get protein from both plant and animal sources. Some healthy protein-rich foods include red meat, poultry, dairy products, eggs, seafood, soy (including tofu and tempeh), beans and legumes, and nuts and seeds. Animal-based protein sources are particularly useful as they contain high amounts of the amino acid leucine, which acts as a metabolic switch to turn on muscle building.
You may have heard concerns over a high-protein diet causing kidney damage; however, recent research shows this to be untrue. (5) Ultimately, if you’re concerned about your protein intake and kidney health, it’s best to speak to a doctor.
It’s also important to note that 1.5 g of protein per kg of bodyweight is a general recommendation and not a substitute for medical advice. For personalised guidance, consult with a registered dietitian or other qualified health care professional.
What if I eat too little protein?
Protein deficiency is very rare, and most people generally don’t have trouble meeting the RNI on protein. However, some groups of people, such as older adults, people with disabilities, and those that over restrict calories, are more at risk of a protein deficiency. (6)
Not eating enough protein — i.e. less than the RNI of 0.75 grams per kilogram of bodyweight — can result in health issues. If you regularly don’t eat enough protein, it could cause muscle loss, feeling weak or trouble thinking, a weakened immune system (getting sick often), brittle hair and nails, muscle weakness, and stress fractures. (7)
A final note from Lingo
Protein deficiency in developed countries is very rare. Most people meet the minimum recommendation by NHS for 0.75 g per kg of bodyweight per day. Those at risk of not getting even this minimum amount of protein are older adults, people with disabilities, and those that over restrict calories. (6) Not eating the minimum amount of protein could cause muscle loss, feeling weak or trouble thinking, a weakened immune system (getting sick often), brittle hair and nails, muscle weakness, and stress fractures. (7)
If your protein intake is somewhere around the government recommended minimum, while that may be enough to avoid deficiency, it's not optimal. If you find yourself hungry soon after you've eaten, have unsteady energy levels, or never seem to be making much progress in the gym, try aiming for 1.5 g/kg per day and see how you feel.
Consuming enough protein helps improve your body composition as it aids in building and maintaining lean muscle and supporting body fat loss by promoting satiety and curbing hunger. Protein also balances your glucose levels by slowing down the absorption of carbs and helping with appetite control and more stable energy levels.
To get more protein in your day, try centring meals around high-protein foods such as lean meat, poultry, seafood, and tofu, and opt for snacks such as Greek yoghurt, edamame, nuts and seeds, and jerky.