Credit: Getty Images
Protein has become the star of the modern diet. From shakes, bars and powders to viral fitness advice, the message seems clear: more protein equals better health.
But research from Texas A&M University suggests it’s not that simple.
For decades, nutrition guidance has centered on a single benchmark: about 0.8 grams of protein per kilogram of body weight per day. That recommendation was designed to meet the needs of nearly all healthy people, and it remains the standard used in dietary guidelines today.
According to Dr. Nicolaas Deutz, director of the Center for Translational Research in Aging and Longevity, the problem is that this guideline was never meant to apply to everyone. Two people with the same body weight may have different requirements depending on factors like sex, activity level, age and overall health.
“We need to think more on an individual basis,” Deutz said. “You cannot take one value. Protein requirements were never meant for special populations — they were only meant for healthy, young people. When you get older, your requirements change, and more importantly, if you have a chronic disease, your requirements are also different. So, you cannot use this one number in all cases.”
If you’ve been trying to hit a specific protein goal every day, here’s some reassurance: you’re likely already getting enough. Deutz said that for the average healthy person, especially in the United States, protein intake is generally more than sufficient.
The limits of a one-size-fits-all protein guideline
Part of the issue lies in how protein needs have traditionally been measured, Deutz said.
Researchers have traditionally relied on methods that track amino acids in the bloodstream to estimate how much protein the body breaks down and needs to replace. But those measurements don’t fully capture what’s happening inside the body’s cells, where protein turnover takes place. As a result, they can underestimate how much protein the body is actually using.
To address that gap, Deutz and his colleagues developed a newer approach, described in the journal Clinical Nutrition, using stable isotope tracers that better reflect what’s happening inside the cell.
In the study, participants were measured in the morning after an overnight fast, when the body is not influenced by recent meals. Deutz said this fasted state provides a snapshot of baseline protein loss, which can be used to estimate how much protein the body needs over the course of a full day.
“With one simple measurement in the morning after an overnight fast, we can actually establish what your needs are on an individual basis,” Deutz said.
Using this approach, the researchers found that protein breakdown in the body may be significantly higher than previously estimated, helping explain why a single universal guideline may not reflect individual needs.
A shift to precision nutrition
Deutz said the future of nutrition lies in tailoring recommendations to the individual.
“This is what we call precision nutrition and individualized protein needs,” he said.
This approach considers factors like a person’s habitual diet, health status and physiology, recognizing that two people of the same size may have very different nutritional needs. For example, in medical settings, Deutz said relying on standard protein guidelines without considering a patient’s usual intake can sometimes lead to undernutrition.
For most people, the broad takeaway is not that people should eat more protein, but that they should think about it differently.
Instead of chasing a universal number, Deutz said, the focus should shift toward understanding individual needs and context.
More information: A novel pulse tracer method to estimate the relationship between amino acid meal composition and its intracellular disposal, Clinical Nutrition, (2025).
DOI: 10.1016/j.clnu.2025.10.002
https://www.clinicalnutritionjournal.com/article/S0261-5614(25)00274-2/fulltext
Journal information: Clinical Nutrition
More information: A new concept to establish protein requirements, Clinical Nutrition, (2025).
DOI: 10.1016/j.clnu.2025.02.00
https://www.clinicalnutritionjournal.com/article/S0261-5614(25)00037-8/abstract
Journal information: Clinical Nutrition