New Harvard Study Says You Don’t Need Meat, Plant-Based Diet Provides Complete Nutrition

3 Mins Read

In a recent study published in Scientific Reports, researchers confirmed that all our nutritional needs can be satisfied without eating meat. In addition to being nutritionally sound, choosing plant-based alternatives would be more environmentally optimal, and conserve more protein and energy than conventional meat. Faced with our global climate breakdown, biodiversity loss and health epidemic, this study adds to the plethora of scientific research that supports the switch to a plant-based food system.

The study was conducted by a team of nutritionists, physicists and scientists from Harvard University, Harvard College, and New York’s Bard College. Their key finding was that by replacing beef, chicken and pork meat with plant alternatives made from soy, green pepper, squash, buckwheat and asparagus, the nutritional needs of Americans could be fully met. The study also found that the replacement of conventional meat with plant-based alternatives would eliminate pasture-land use, lower the area needed for cropland, and save 280 million metric tonnes of greenhouse gas emissions every year. To put this into perspective, if Americans were to cut out meat intake, it would translate to taking 60 million cars off the road. 

This study backs up what we already know about the animal agriculture industry. Raising livestock comes with an enormous carbon footprint – accounting for around 18% of human produced greenhouse gas emissions every single year, according to the UN Food and Agriculture Organisation (FAO). Traditional livestock farming is also land and water intensive – it degrades soil, is responsible for water pollution, and contributes to our ongoing deforestation problem. With 30% of land globally being used as pasture land or to grow grain to feed livestock, our current food system is inefficient and in need of an overhaul. As pointed out by the IPCC’s most recent landmark report, the world needs to transition into a plant-based system if we are to sustain humanity. Last October, scientists at the EAT-Lancet Commission called for the adoption of a “planetary health diet”, which consisted of a dramatic reduction of meat and dairy and a doubling of pulses, nuts, fruits and vegetables.

Lead researcher of the study, Eshel, and the team wanted to find out what would happen if all Americans stopped eating meat and replaced it with plant protein in the same daily doses. In addition to eliminating a colossal amount of carbon dioxide emissions, their results showed that 29 million hectares of crop land and 6.6 billion kilograms of nitrogen fertiliser would be saved. While food-related water use would rise by 15%, Eshel said that meatless replacements emits 80% less carbon than conventional meat. 

One of the most important findings of the study, which would convince more people to consider reducing their meat intake, is that plant-based proteins could be just as, if not more nutritious than the real animal counterparts in terms of protein, vitamin and fatty-acid contributions. Buckwheat and tofu, for instance, would deliver one third of the total protein needs in a meatless diet, with a much lower environmental impact. 

Scientists concluded that while a complete overhaul of the American food system would be logistically and culturally challenging, going meatless remains the best option that we can take to reduce resource use on a multidimensional level.  

“There’s something empowering about these results, because they offer people a sense of agency in terms of determining their own impact,” said Eshel. Indeed, this study could crucially reassure skeptics that ditching meat would not leave people lacking in nutrition, and could help save the planet too. 

Lead image courtesy of Vegetarian Nation.


  • Sally Ho

    Sally Ho is Green Queen's former resident writer and lead reporter. Passionate about the environment, social issues and health, she is always looking into the latest climate stories in Hong Kong and beyond. A long-time vegan, she also hopes to promote healthy and plant-based lifestyle choices in Asia. Sally has a background in Politics and International Relations from her studies at the London School of Economics and Political Science.

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