In this LAB note
Question · Hypothesis · Method · Results · What Failed · What We Learned · What Changed at MOMS
Question
When a shake needs to hit roughly 30g of protein, is it better to split that target across several plant sources, or to deliver it from one complete, highly digestible protein?
Hypothesis
We expected blending to win. Mixing legumes with dairy or egg should, in theory, cover each other's limiting amino acids — the classic complementary-protein idea — so we predicted multi-source recipes would score at least as well as single-source ones at matched protein grams, and probably better.
Method
We drew on two lines of published research. First, a comprehensive DIAAS comparison of plant- and animal-sourced proteins (Herreman et al., Food Science & Nutrition, 2020), which quantifies how much lower most legume proteins score than egg, dairy, and soy once true amino-acid digestibility is counted. Second, a dual-isotope tracer study measuring the true ileal digestibility of individual legumes in adults (Devi et al., American Journal of Clinical Nutrition, 2019). Internally, we analyzed all 201 recipes in our formulation database, grouped them by number of distinct protein sources and by whether they stacked two or more legumes (chickpea, lentil, bean), and compared each group's internal formulation Score.
Results
The direction was opposite to our hypothesis. Single-protein-source recipes averaged a Score of 15.88 (n=32), while four-source recipes averaged 14.28 (n=18). Recipes stacking two or more legumes averaged 14.42 (n=19) versus 15.04 for everything else. Every recipe scoring a perfect 20 used one concentrated complete protein: EY-W4-CALM-001-V1 (Egg White 220g, 33.3g protein), EI-W2-WARM-001-V1 (Egg White 195g, 37g protein), and WAI-W3-NUTR-001-V1 (Chicken 90g, 36.5g protein). The lowest scorers did the opposite: EI-W4-RENEW-007-V1 fragmented protein across Chickpeas 30g + Lentils 30g + White Beans 30g + Egg White 195g on an all-almond-milk base, labeling 32.3g protein but scoring only 12; WY-W1-DETOX-017-V1 (Tofu 50g + Chickpeas 30g + Greek Yogurt 177g, 31.6g protein) scored 11. The published numbers explain why: true ileal digestibility was 74.6% for chickpea, 71.6% for yellow pea, and 63.2% for mung bean (Devi 2019) — well below the ~90%+ of egg white and soy.
What Failed
Our cruder first version — 'fewer sources is always better' — did not survive the data. Three-source recipes averaged 15.05, edging out two-source recipes at 14.76, so raw source count is not the lever. A well-chosen three-source blend (soy + egg white + tofu, all mid-to-high DIAAS) scored as well as a single-source recipe. What consistently dragged Scores down was stacking several low-digestibility legumes on a near-zero-protein almond-milk base — a quality problem masquerading as a count problem.
What We Learned
Protein quality — completeness plus true digestibility — matters more than the number of sources or the number printed on the label. Spreading a protein target across chickpeas, lentils, and beans can quietly under-deliver usable amino acids even when the on-label total reads a healthy 30g+.
What Changed at MOMS
We now require every recipe to carry at least one high-quality anchor protein (egg white, soy, dairy, or lean meat), and we cap the share of total protein that may come from low-DIAAS legumes. Almond-milk bases, which contribute almost no protein of their own, can no longer be paired with a legume-only protein stack; they must sit alongside a concentrated complete anchor. Legumes stay for fiber, minerals, and texture, but no longer carry the protein target alone.
References
1. Herreman L, Nommensen P, Pennings B, Laus MC. Comprehensive overview of the quality of plant- and animal-sourced proteins based on the digestible indispensable amino acid score. Food Science & Nutrition. 2020;8(10):5379-5391. https://doi.org/10.1002/fsn3.1809 2. Devi S, Varkey A, Sheshshayee MS, et al. True ileal digestibility of legumes determined by dual-isotope tracer method in Indian adults. American Journal of Clinical Nutrition. 2019;110(4):873-882.
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