Research

Hormonal

Consuming a protein- and leucine-enriched bar (containing ~16g protein and 1.5g free leucine) two hours after a low-protein breakfast increases peak plasma leucine and essential amino acid exposure to levels comparable to a high-protein breakfast, while significantly reducing hunger and increasing fullness in older adults.

For older adults who struggle to eat large breakfasts, adding a small, leucine-enriched protein bar about two hours after a light breakfast can boost muscle-building signals and keep hunger away just as effectively as a much larger, high-protein breakfast. Look for bars with ~1.5g of free leucine and ~16g of mixed protein.

ModerateSupportsMEDIUM confidence
Consuming our bar formulation increased blood leucine availability and net exposure to EAAs to a similar degree as consuming a high-protein meal... High-protein at breakfast results in a greater net exposure to EAAs and leucine, which could support MPS in older persons.
Daniel A. Traylor et al. · Current Developments in Nutrition · 2021

Why this rating

Randomized crossover design with a small sample size (n=8) and short duration (6h postprandial), limiting generalizability to long-term muscle mass changes.

Source

Consumption of High-Leucine-Containing Protein Bar Following Breakfast Impacts Aminoacidemia and Subjective Appetite in Older Persons

Daniel A. Traylor et al. · Current Developments in Nutrition · 2021

DOI 10.1093/cdn/nzab080

crossover · n=8Cited 8×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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