What is a good amount of protein per day, and does it change when taking Glucagon-like peptide (GLP) medication, such as semaglutide (GLP-1 receptor agonist) or liraglutide (GLP-1 receptor agonist)?

Protein Requirements for Adults

For healthy adults with minimal physical activity, consume 0.8 g protein per kg body weight per day, and this recommendation does not change when taking GLP-1 receptor agonist medications like semaglutide or liraglutide. 1

Standard Protein Recommendations

The recommended dietary allowance for protein is 0.8 g/kg body weight per day for healthy adults with minimal physical activity. 1 This represents the baseline requirement for maintaining structural protein needs and preventing deficiency. 2

However, this baseline recommendation increases based on activity level:

• Minimal physical activity: 1.0 g/kg/day 2
• Moderate physical activity: 1.3 g/kg/day 2
• Intense physical activity: 1.6 g/kg/day 2
• Athletes and trained individuals: 2.2 g/kg/day or higher 3

Upper Safety Limits

Long-term protein consumption at 2 g/kg/day is safe for healthy adults, with a tolerable upper limit of 3.5 g/kg/day for well-adapted individuals. 2 Chronic high protein intake exceeding 2 g/kg/day may result in digestive, renal, and vascular abnormalities and should be avoided. 2

When protein constitutes more than 35% of total energy intake, dangers include hyperaminoacidemia, hyperammonemia, hyperinsulinemia, nausea, diarrhea, and potentially death. 4 A suggested maximum safe intake is approximately 25% of energy requirements at 2 to 2.5 g/kg/day. 4

Special Considerations for Chronic Kidney Disease

For patients with stages 3-5 non-dialysis-dependent chronic kidney disease, dietary protein intake should be 0.8 g/kg body weight per day. 1 This level slows glomerular filtration rate decline with evidence of greater effect over time. 1

Higher protein intake (>20% of daily calories or >1.3 g/kg/day) should be avoided in CKD patients as it has been associated with increased albuminuria, more rapid kidney function loss, and cardiovascular mortality. 1

Reducing protein below 0.8 g/kg/day is not recommended because it does not alter blood glucose levels, cardiovascular risk measures, or the course of GFR decline. 1

For patients on dialysis, higher levels of dietary protein intake should be considered since protein-energy wasting is a major problem. 1

GLP-1 Receptor Agonists and Protein Requirements

There is no evidence that protein requirements change when taking GLP-1 receptor agonist medications. The diabetes care guidelines that discuss GLP-1 receptor agonists (liraglutide, semaglutide, dulaglutide) make no mention of altered protein requirements for patients on these medications. 1

The standard protein recommendation of 0.8 g/kg/day remains appropriate for patients taking GLP-1 receptor agonists, whether for diabetes management or weight loss. 1

Important Caveats for GLP-1 Users

While protein requirements don't change, patients on GLP-1 receptor agonists should be aware that:

• Gastrointestinal side effects (nausea, vomiting, diarrhea, constipation) occur in 15-44% of patients and may affect protein intake tolerance. 5
• Nutritional status should be monitored regularly during GLP-1 treatment. 6
• Reducing meal portion sizes is recommended to manage side effects, which may require more frequent protein-containing meals to meet daily requirements. 5

Practical Implementation

For an 80 kg adult:

• Minimal activity: 64 g protein/day (0.8 g/kg)
• Moderate activity: 104 g protein/day (1.3 g/kg)
• Intense activity: 128 g protein/day (1.6 g/kg)
• Maximum safe intake: 160 g protein/day (2.0 g/kg)

Prioritize high-quality proteins from animal products (lean meat, milk) for optimal growth, development, and health. 2