Adults should aim for 0.8 grams of protein per kilogram of body weight per day as a baseline for healthy maintenance. This Recommended Dietary Allowance set by the Food and Nutrition Board, National Academies of Sciences, Engineering, and Medicine translates into roughly 0.36 grams per pound and into practical amounts such as 56 grams for a 70 kilogram adult and 46 grams for a 57 kilogram adult. The Office of Dietary Supplements at the National Institutes of Health provides these examples and explains the basis for the population-level recommendation. Individual needs can differ from this baseline based on age, activity, illness, and body composition goals.
How recommendations are determined
The 0.8 grams per kilogram figure is derived from balance studies that measure nitrogen intake and loss to estimate the amount needed to maintain lean mass in healthy, sedentary adults. The Food and Nutrition Board, National Academies of Sciences, Engineering, and Medicine used that body of evidence to set the RDA. Clinical and population research led by experts such as Stuart M. Phillips at McMaster University highlights that this reference intake prevents deficiency for most adults but does not necessarily optimize muscle maintenance or recovery for everyone.
When to aim higher
Certain groups commonly benefit from intakes above the baseline. Older adults often require more protein to counteract age-related muscle loss, with many researchers recommending intakes near one to 1.2 grams per kilogram to preserve function. Physically active people and athletes typically aim between 1.2 and 2.0 grams per kilogram depending on training intensity and goals, as summarized by the International Society of Sports Nutrition. During illness, recovery from surgery, or significant weight loss efforts, clinicians often prescribe higher protein to support tissue repair and immune function. Higher protein targets should be personalized and monitored, particularly in clinical contexts.
Insufficient protein over time leads to progressive loss of muscle mass, impaired wound healing, and increased susceptibility to infections. On a population level, insufficient intake in regions with limited food variety can compound childhood stunting and reduced workforce capacity. Conversely, very high protein intake in otherwise healthy people is generally well tolerated, but people with chronic kidney disease require tailored guidance from nephrology experts and organizations such as the National Kidney Foundation because impaired kidney function changes how protein is handled.
Quality, culture, and environment
Protein needs are met through a mix of animal and plant sources whose amino acid patterns and digestibility differ. High quality animal proteins are typically more bioavailable, but thoughtfully combined plant proteins can meet needs in vegetarian and vegan diets. Cultural food patterns shape feasible protein choices and portion sizes, while environmental considerations influence recommendations at population scale because animal protein production has higher greenhouse gas and land use footprints than many plant proteins. Dietary advice should therefore respect cultural preferences, nutritional adequacy, and sustainability where relevant.
For most healthy adults, using the simple rule of 0.8 grams per kilogram offers a reliable starting point, then adjusting upward for older age, higher activity, or clinical needs under professional guidance.