There’s a ton of confusing information regarding how much protein to eat. Proponents of body-building and increasing lean body mass suggest to consume as much as 1-2 g per pound of weight, which may end up being too high particularly for people in overweight or obese category.
The current recommended dietary allowance (RDA) for protein is 0.8 grams per kilogram (g/kg) of body weight a day for adults over 18, or about 2.3 ounces (65 g) for a 180-pound adult.
RDAs are values identifying the minimum amounts of a nutrient or element that is needed to not develop deficiency or get sick – so they do have limitations and should be used as guidelines or benchmarks, not necessarily as precise recommendations.
Some scientists studying how nutrition effects longevity and health span insist that generally Americans consume too much protein by making it the center piece of any plate (eggs for breakfast, chicken or beef for lunch and dinner). Dr. Valter Longo in his book Longevity Diet and several research studies published over the years suggests to consume no more than 0.36 g of protein per pound of body weight. For a 150 lbs person that would be 54 g a day (similar to RDAs). According to him, any protein in access of this amount not only isn’t helpful in muscle preservation and growth, but could be harmful through initiating pathways that are implicated in ageing and even development of cancer, cognitive decline and degenerative diseases and other chronic diseases.
Mind you, most foods you eat contain protein – both animal and plant sources. You don’t have to gorge on chicken breast and greek yogurt to ensure you get the recommended amounts – a serving of rice and beans combo can supply you with as much as 20 g of complete (meaning it has all essential amino acids) protein.
Protein is the most thermogenic (requires most energy to be digested) out of all macros. It also keeps you satiated for longer, meaning you won’t be getting hungry as often, which may lead to reduced food consumption.
However too much protein (when in excess of your energy needs) may be converted to sugar in the liver, which in turn might end up as fat in your fat cells. Therefore more is not necessarily better.
If you track your food intake, aim for anywhere between 15-25% calories from protein sources (1 g of Protein is worth 4 calories – practice some math here) – for me that is around 65-100 g. It’s quite a spread, though it all depends on how active I am on any particular day, whether I’m doing resistance training or maybe recovering from a cold.