How Much Protein Should You Really Eat Daily? | David Allison, Ph.D.

Aiming for approximately 2 grams of protein per kilogram of body weight daily is recommended for optimal health and performance, with little evidence of harm and clear benefits.

• Aim for 1.6 to 2 grams of protein per kilogram of body weight daily for optimal health.

• Higher protein intake shows benefits for body composition, strength, and appetite control with no clear evidence of harm.

• Claims of 'high protein' dangers lack support from rigorous human intervention studies.

For most individuals, consuming around 1.6 to 2 grams of protein per kilogram of body weight per day is advised to 'thrive,' as opposed to merely meeting the basic Recommended Dietary Allowance (RDA). While benefits may diminish above 2 grams per kilogram, there is no strong evidence of harm for higher protein intake in healthy individuals, and substantial evidence supports its benefits for various health outcomes. This recommendation emphasizes a data-driven approach, challenging claims of 'high protein' harms without robust human intervention study evidence.

Protein Intake Guidelines

• 00:00:47 General guidance recommends consuming about 1.6 to 2 grams of protein per kilogram of body weight daily, which is roughly equivalent to one gram per pound of body weight. This target allows individuals to 'thrive,' whereas the RDA primarily supports basic survival. For those with dietary restrictions like vegetarians or vegans, the goal is to maximize intake, though it may not exceed 1.2 grams per kilogram.

Diminishing Returns and Costs

• 00:01:56 While strong evidence supports consuming around 2 grams of protein per kilogram, benefits begin to diminish above this level, reaching an asymptote. Higher intake might incur economic costs from specialized products, time and attention, or opportunity costs of not consuming other preferred foods. The decision to push protein intake further depends on refined individual goals, such as competitive athletic performance.

Benefits of Higher Protein Intake

• 00:03:29 Evidence clearly indicates benefits when increasing protein intake from the RDA level (around 0.8 grams per kilogram) to double or slightly more than two grams per kilogram. These benefits include improvements in body weight, appetite control, bone strength, and muscle mass, particularly for those recovering from injury, bodybuilding, athletes, older individuals, and growing children. There is little to no evidence of harm for most groups, even in individuals with chronic kidney disease, despite common concerns.

Challenging Harm Claims

• 00:04:44 A direct challenge was issued to experts to provide human, controlled, intervention studies demonstrating deleterious effects of 'high protein' intake on clinically or intrinsically meaningful endpoints. The focus is on outcomes like longevity, appearance, strength, and function, rather than changes in isolated molecules or gut microbiota that lack intrinsic significance. To date, no such robust evidence has been presented, suggesting that concerns about high protein intake are not well-supported by scientific data.