# Animal and plant proteins and glucose metabolism

> **NIH NIH R01** · WASHINGTON UNIVERSITY · 2021 · $568,019

## Abstract

Abstract
Nearly 65% of adults in the United States actively try to increase their protein intake by
consuming naturally protein-rich foods and foods and drinks fortified with protein isolates to
improve their health. However, data from recent population studies have shown high protein
consumption is associated with an increased risk of developing type 2 diabetes (T2D). This
adverse effect might be specific to the type of protein consumed because several studies have
found high animal protein, but not high plant protein, consumption was associated with
increased T2D risk. There is experimental evidence from studies conducted in people and in
mice to support a causal relationship between dietary protein intake and metabolic dysfunction.
However, the effect of chronic high protein intake on glucose homeostasis and the mechanisms
that cause protein-mediated metabolic dysfunction are not known. The reason(s) for the
differences in the metabolic effects observed between high animal protein and high plant protein
consumption are also not known, but could be due to differences in the amino acid composition
and structure of animal and plant proteins per se and/or their biological matrix, which includes
complex cell walls, lectins, and protease inhibitors in protein-rich plant foods, that can impair gut
microbial access to proteins and/or induce the microbial production of beneficial metabolites,
such as short-chain fatty acids. The goal of this proposal is to determine the effect of a high-
protein diet in which the increase in protein intake is derived from different sources (animal vs
plant and protein-rich whole foods vs protein isolates) on: i) liver and muscle insulin sensitivity;
ii) the metabolic response to a meal, and iii) 24-h plasma concentration profiles of glucose,
glucoregulatory hormones, and protein-derived metabolites purported to cause metabolic
dysfunction. Our overarching hypothesis is that diets enriched with either animal or plant protein
isolates, or animal protein-rich whole foods, but not plant protein-rich whole foods, cause
alterations in the plasma hormones and protein metabolites that can cause insulin resistance
and stimulate hepatic glucose production, thereby raising 24-h plasma glucose concentration.

## Key facts

- **NIH application ID:** 10089440
- **Project number:** 5R01DK121560-03
- **Recipient organization:** WASHINGTON UNIVERSITY
- **Principal Investigator:** Samuel Klein
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $568,019
- **Award type:** 5
- **Project period:** 2019-04-01 → 2024-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10089440

## Citation

> US National Institutes of Health, RePORTER application 10089440, Animal and plant proteins and glucose metabolism (5R01DK121560-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10089440. Licensed CC0.

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