Introduction: Limited research has been conducted on short-term healthful diet challenges to optimize phenotypic flexiblity.
Aim: We hypothesized that a short-term, plant-based protein (vegan) diet regimen nutritionally balanced in macronutrient composition to an omnivorous (animal protein) diet would have measurable, beneficial effects on metabolic measurements of blood sugar regulation, blood lipids, and amino acid metabolism.
Materials and Methods: A randomized, cross-over, controlled vegan verses animal diet challenge study was conducted on 21 (11 female and 10 male) healthy participants. Fasting plasma was collected at baseline and before and after each 2-day diet intervention to measure clinical variables, metabonomics, and bile acids. Intervention diet meal plans were tailored to calculated individual caloric needs. All foods were provided and the majority of meals and snacks were supervised. Intervention diet compliance was monitored and actual intake was calculated.
Results: The vegan diet lowered fasting triglycerides, insulin and HOMA-IR, bile acids, elevated magnesium levels, and changed BCAA metabolism which may further potentiate insulin and blood sugar control after just 48 hours. Cholesterol control as assessed by a lower CHOL/HDL ratio improved significantly from the vegan diet. Significant differences seen in plasma amino acid and magnesium responses positively correlated with dietary amino acid composition changes between plant- and animal-based diets. Polyunsaturated fatty acids and dietary fiber were inversely correlated with insulin, HOMA-IR and triglycerides. The short-term dietary changes that improved measurements of health were impacted by sexual dimorphism; including, baseline nutritional biochemistries; BCAAs at baseline and post-intervention with males having higher plasma levels; and insulin and HOMA-IR post-intervention with females having higher plasma levels.
Conclusions: This study demonstrates that a health-promoting, BCAA-associated metabolic signature can be obtained from a short-term, healthy, vegan diet challenge. The long-term impact of periodic short-term vegan diet challenges is a promising research concept and an approach that may be used to promote sustainable intake of protein sources and improve phenotypic flexibility as a measure of health.
Acknowledgements: Nestle Institute of Health Sciences, Metabolic Unit-Nestle Research Centre
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