How Much Protein Do You Really Need? With Kimberly Parsons
We all know that consuming a sufficient amount of daily protein is essential to power your body, build and maintain muscle. No one is disputing that! But how much does your body really need?
According to the British Nutrition Foundation the daily Reference Nutrient Intake (RNI) is set at 0.75g of protein per kilogram bodyweight per day in adults. This equates to approximately 56g/day and 45g/day for men and women aged 19-50 years respectively (requirements vary depending on age and stage of life – infants aged 1-3 require 12g/day, children aged 9-13 require 30g/day and an increase in pregnancy (an additional 6g/d) and lactation (an additional 11g/d 0-6 months and 8g/d 6+ months)).
However, most humans living on a westernised diet consume far more daily protein than their bodies require for health. Currently, the average daily intake of protein in the UK is 88g for men and 64g for women with over 37% being provided by meat or meat products, compared to 10% from plant-based products including nuts and seeds.
In part this is due to government subsidies towards corn, soy and other grains that are fed to industrial-farmed animals, poultry and even fish. Meaning, animal protein has become very inexpensive to the consumer, thus the reason meat, poultry and fish products feature so commonly in the westernised diet.
While the excess protein we consume can be used to provide energy for your body (1g of protein provides 17kJ (4 kcal)), consuming large amounts of certain amino acids such as methionine, leucine and isoleucine may promote rapid aging and cancer growth. New studies have brought some additional insights into the protein discussion. Many studies tested on animals have established that calorie restriction leads to increased longevity, but the latest science suggests this phenomenon may actually result more from reduced protein intake. Specifically, reduced intake of the amino acid methionine, which happens to be high in meats.
So the question is, do we REALLY need this much daily protein after-all? What you may not realise is that your body has a very smart, built-in strategy to ensure you receive enough protein. Your body recycles essential amino acids so you don’t need to give your body a new batch of these essential proteins everyday. Your body can actually recycle approximately 20 grams of your own protein from mucus and gut lining cells that are replaced in your gut. Isn’t your digestive system economical and smart!
In light of this, there now seems to be consensus amongst some scientists that people require only 0.37 grams of protein per kilogram of body weight, exactly half of the recommended RDI. This means that an adult male and female would only require 28g and 22.5g of dietary protein per day respectively (you can calculate your own daily protein needs by multiplying your weight in kilos by 0.37 grams) and your body's own recycling system will provide you with the extra 20g giving adult males and females a well rounded total of 48g and 42.5g respectively.
All you need to do is continue to consume a varied diet and let your body do the rest.