The Environmental Costs of Building Human Muscle

Summary

Among the general population, it has been established that plant-based diets confer significant environmental benefits (greenhouse gas emissions, land use, and water use) compared to omnivorous diets.

However, sports nutrition recommendations for supporting resistance exercise-induced gains in muscle mass and strength differ substantially from population-level recommendations, especially for protein intake. Therefore the difference in environmental impact between omnivorous and plant-based diets for adults following such recommendations is as yet unknown.

A prior analysis found that a high-protein, non-animal-derived diet can support resistance training-induced gains in muscle mass and strength to the same extent as a protein-matched omnivorous diet. These findings align with previous research showing that, in the context of a high-protein diet, the source of protein - whether animal or plant-based - does not affect the rate of resistance exercise-induced gains in muscle mass and strength.

The present study therefore plans to retrospectively analyze the diet records from previously published research to determine the difference in environmental impact between the high protein animal-free and omnivorous diets.

The findings could highlight the unique difference in environmental impacts between those following high protein plant-based and omnivorous diets.

Conditions

• Greenhouse Gas Emissions
• Water Use
• Land Use

Interventions

BEHAVIORAL

VEG2

Participants were provided with a caloric target to place them in a ∼0 to 10% energy surplus, and a protein target of 2 g·kg bm-1·d-1. Participants were instructed to avoid animal products for ≥6 d per wk, focusing their intake on protein-rich non-animal-derived foods (for example, mycoprotein-containing products, pulses, soy). To facilitate reaching protein intake targets, the research team provided participants with mycoprotein-containing vegan products (∼1-2 products per day) to be used as the main protein source for some meals. This group also received 105-g mycoprotein (46-g protein, 10-g carbohydrate, 13-g fat, 348 kcal), 35-g post-training, and 70-g before bed.

BEHAVIORAL

OMNI2

Participants were provided with a caloric target to place them in a ∼0 to 10% energy surplus, and a protein target of 2 g·kg bm-1·d-1. Participants in OMNI2 were instructed to consume an omnivorous diet, focusing their intake on high-quality animal-derived proteins (that is, meat, milk, yogurt, cheese). To facilitate reaching protein intake targets, the research team provided participants with a weekly supply (∼1-2 products per day) of chicken or beef to be used as the main protein source for some meals. This group also received 59-g supplemental milk protein daily (47-g protein, 2-g carbohydrate, \<1-g fat, 198 kcal) 19.5-g to drink post-training and 39-g to drink before sleep.

Sponsors & Collaborators

• University of Exeter

  collaborator OTHER

• Game Changers Institute

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

40 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2018-05-01

Primary Completion

2020-03-01

Completion

2020-03-01

Countries

• United States

Study Locations