Interest in protein is at an all-time high. As the “protein maxxing” trend gains traction, healthcare professionals are continually asked “How much protein do I need?”
Historical protein recommendations were designed to prevent inadequacy. Now, the discussion has evolved to consider optimal protein needs for specific populations and life stages.
This article reviews U.S. protein intake trends and examines evidence-based recommendations for optimal protein intake among adults, older adults, athletes, and people actively trying to lose weight.
Protein in Focus
Protein is often seen as a signal of health in food. In the 2025 IFIC Food & Health Survey, “good source of protein” ranks first among criteria Americans use to define a food as healthy (1). In the same survey, 70% of Americans report trying to consume more protein, the most of any nutrient (1).
Reasons for seeking more protein vary. Some people want to gain muscle mass and strength. Others are looking for more energy or to improve well-being (2). Anecdotally, many people consume protein because they believe it to be more satiating.
Despite increased interest and an influx of new foods and beverages boasting more protein, National Health and Nutrition Examination Survey (NHANES) data finds no significant change in protein consumption among adults (3). In fact, some populations continue to miss the mark. Twenty three percent of adolescent girls, 14% of females age 71 and older, and 9% of males age 71 and older fall short on protein (4).
Protein Recommendations
People hear conflicting guidance about how much protein to eat. Nutrition labels, websites, and social media influencers all have different advice. Healthcare professionals who understand the basis for different recommendations can help clear confusion.
Recommended Dietary Allowance
The federal recommended dietary allowance (RDA) for adult protein intake is 0.8 grams protein per kilogram of body weight per day (g/kg/day) (5).
The RDA was established in 1941 to prevent malnutrition and starvation, which were concerns during World War II. The value was determined based on available nitrogen balance studies and represents the minimum amount of protein needed to meet the basic requirements of nearly all healthy people.
An important distinction is that 0.8 g/kg/day represents the baseline amount of protein sufficient to support cell function and structure. It is considered the minimum, not necessarily the ideal amount.
The RDA, which is now part of the Dietary Reference Intakes (DRIs) established by the National Academies of Sciences, Engineering, and Medicine (NASEM), has not changed. However, a growing body of evidence finds many people benefit from protein intake well above this baseline.
The DRIs for macronutrients, including protein, are currently under review by NASEM. Changes to the RDA may come in the future, though it will depend on the framework used to evaluate the available evidence (6).
Daily Value
Adding to confusion is the daily value (DV). The DV is one value for each nutrient that is used on food and supplement labels. DVs were developed by the U.S. Food and Drug Administration (FDA) to help people determine how much of a nutrient each serving of food provides in relation to the approximate requirement. This is shown as percent DV on a label (7).
The DV for protein is 50 grams. Uniquely, the %DV for protein depends on protein quality, which varies by food source. This is why foods may have a different %DV even if protein grams are the same.
There are multiple ways to measure protein quality. Two commonly used methods are:
- Protein Digestibility-Corrected Amino Acid Score (PDCAAS): This method is used in labeling. It measures amino acid composition while adjusting for digestibility using a fecal nitrogen score (8).
- Digestible Indispensable Amino Acid Score (DIAAS): This approach measures amino acid digestibility at the end of the small intestine, avoiding any confounding factors from gut bacteria or amino acid loss in the large intestine (8).
In general, animal-source foods are higher quality and will show a higher %DV compared with plant-source foods with the same grams of protein.
Dietary Guidelines for Americans
The Dietary Guidelines for Americans (DGA) is food-based guidance updated by the U.S. Department of Health and Human Services (HHS) and U.S. Department of Agriculture (USDA) every five years. The 2025-2030 edition made headlines by suggesting Americans consume 1.2-1.6 g/kg protein per day (9).
To put this in perspective, for a 150-pound person:
- RDA is 55 grams of protein daily
- DGA suggests 80-110 grams of protein daily
The DGA is accompanied by an appendix outlining the scientific basis for this shift. Overall, a rapid systematic review found 1.2-1.6 g/kg/d protein from high-quality and nutrient dense sources supports health and disease prevention (10).
Optimal Protein: Individualizing Guidance
While general guidance exists, optimal protein varies individually. Optimal protein goes beyond the baseline requirements of the RDA. It considers protein needed to support satiety, weight management, nutrient adequacy, muscle protein synthesis, and general health and well-being (11).
Most often, optimal protein is in line with the latest guidance of 1.2–1.6 g/kg/day. However, personalization is key. Factors like age, health status, goals, and lifestyle play a role in determining optimal protein needs. Some populations, such as people trying to lose weight, athletes, and older adults, require specific consideration.
For populations who often eat less overall, like those trying to lose weight or older adults, protein quality is especially important to consider. Choosing high quality protein helps ensure nutrition needs are met.
Weight Loss Therapy
People utilizing weight loss methods including glucagon-like peptide-1 receptor antagonists (GLP-1 RAs) are at risk of nutrition deficiencies and losing lean mass. With any significant weight loss, preserving muscle mass is an area of concern as overall body mass decreases.
Evidence shows that for people actively losing weight, a personalized diet with 1.2-2.0 g/kg (based on target body weight) is recommended (12). It is also important to consider the quality of protein as diminished appetite and limited calorie intake can make it harder to consume sufficient micronutrients (13).
Athletes
Protein recommendations for athletes vary depending on the type of activity the athlete is predominantly doing.
Typical recommendations for athletes are:
- Endurance: 1.6-1.8 g/kg/d (14)
- Strength-training: 1.6-2.0 g/kg/d (15)
- Building or maintaining muscle mass, 1.4-2.0 g/kg/d (16)
Still, optimal needs will vary and personalization is key. For example, the International Society of Sports Nutrition (ISSN) suggests athletes who are training for ultramarathons consume about 1.6 g/kg/d to maintain lean mass and support recovery. However, they advise up to 2.5 g/kg/d may be needed during demanding training when calorie requirements are greater (17).
ISSN also acknowledges emerging evidence that suggests protein intake above 3.0 g/kg/d may help promote loss of body fat in people who exercise using resistance training (16).
Older Adults
As people age, concerns around sarcopenia and muscle loss increase. Protein recommendations for this population shift to prevent or slow the decline of muscle mass and strength. Older adults may also eat less and be less physically active, and comorbidities may impact the way protein is absorbed and used in the body, known as anabolic resistance (18). This makes protein quality even more important.
Evidence from large observational studies suggests that along with resistance training, 1.0-1.3 g/kg/d of dietary protein can optimize physical function in older adults (18, 19).
Key Takeaways for Practice
Most adults meet the baseline protein RDA to prevent deficiency but may still fall short on protein for their own unique needs. NHANES data finds adults ages 20 years and older consume about 1 g/kg/d (3).
Healthcare professionals can support patients by shifting the conversation from “high protein” to “optimal protein,” a more suitable framing. Optimal protein is personalized based on age, activity level, lifestyle factors, and clinical context and is an achievable goal for most people.
Here are some key takeaways for healthcare professionals to consider when making protein recommendations:
- Interest in protein continues to grow. However, many people still fall short on optimal protein: the amount associated with optimal health and function.
- Traditional protein recommendations were designed to prevent inadequacy. Newer guidance may better reflect intake ranges that support broader health goals.
- Protein needs are not one-size-fits-all. Some populations may have higher protein needs, including older adults, athletes, and people using weight loss treatments.
- Populations who generally consume less food and may struggle to meet protein recommendations, including people trying to lose weight and older adults, can benefit from choosing high quality protein foods.
- Personalized guidance can help patients achieve optimal protein in a sustainable, enjoyable, and culturally relevant way.