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The Soy in Soylent | Why we only rely on soybean protein

What is soy?

Ok, before we dive into the specifics of why we chose soybean protein for our meal replacement foods, let’s have a quick moment to refresh on the core topic here: what is soy?

Soy protein isolate is the isolated protein from the soybean that is engineered to create a higher quality of protein.

Throughout this article, you’ll hear us reference soy as soy protein isolate.

Soy protein isolate is the isolated protein from the soybean that is engineered to create a higher quality of protein that is similar to any protein found in animal products—but better.

We’ll get into that later.

Why does Soylent only rely on soybean protein?

Soylent is formulated using vegan ingredients for sustainability and nutritional reasons.

After a few early product iterations made with rice protein, we chose to use soybean protein isolate as the source of protein in our products.

So, what are the benefits of soybeans over other plant proteins?

There are so many benefits of soybean protein over others. But, we chose soy as our main ingredient for all of our meal replacement products because it is a complete source of protein.

In fact, it is the only plant protein to have a PDCAAS score of 1—the greatest score achievable.

We also love soy because it has long-term health benefits, and, of course, we love the taste, too.

Not only do we value flavor and nutritional value, but we also value the planet we all call home. Soybean protein also has a good sustainability track record and because US grown and processed soybean protein is plentiful—something that cannot be said of other plant proteins that often must be sourced from overseas at least partially.1

Soybean protein that is grown and processed in the US must also adhere to strict quality standards and strict limits on heavy metals and other residues.

Soylent professionals in a soybean field

As of 2018, soybeans covered the most acreage of any other crops in the United States —surpassing corn for the first time (USDA NASS 2018). Export tariffs have now impacted these numbers but Soybeans remains a core part of our economy.

The US exports a large amount of soybeans overseas but also supports a strong national food ingredient industry. Soybeans are rich in protein but also in unsaturated oil, which is widely used under the name “vegetable oil”.

Soy protein isolate is the ingredient we use in Soylent as a source of protein.

This ingredient is available from other countries, but we chose US grown and processed soy protein isolate because of the sustainability practices that farmers in the US must adhere to.

The US Soy Sustainability Assurance Protocol is a program in place in the US that a vast majority of soybean farmers comply with (approximately 95%) to demonstrate their commitment to sustainability and continuous improvement.

The protocol covers many aspects of sustainability such as:

- Fair and safe labour practices
- Biodiversity conservation
- Environmental protection
- Continuous improvement

Soybean agriculture often gets a bad rep for it’s sustainability footprint and is often associated in the media with deforestation and poor soil health. But, unlike other countries around the world, the US has these strict sustainability measures in place. With continued use and reliance on US soy, there can be a positive effect on Soy’s global reputation as a sustainable crop.

Does soy cause deforestation?

Soybean production in the US does not translate into deforestation.

The United States is ahead of all other countries in the world for preservation of public forestry lands according to the United Nations Food and Agriculture Organization.2

Since the turn of the 20th century, the amount of forest land in the United States has remained relatively stable (see figure below).

Forest land has increased by 5 million acres between 1982 and 2015, while farmland usage declined during the same period.3, 4 In addition, in the US, soybeans cannot be grown on highly biodiverse grassland, peatland, wetlands, and primary forest.

Cultivated and uncultivated land use chart

International standards on soybean production are improving, but in many countries soybean farming practices are still destructive. Global soybean demand is driving significant deforestation in Brazil (including conversion of savannah and other natural vegetation) in parts of the Cerrado region where 37% of the expansion of soybean cropland between 2005 and 2016 was into newly deforested areas.5

Does soybean production affect soil health?

Soybeans, like other crops grown at large scales have been viewed as having a negative impact on soil health.

Soil health is becoming a hot topic even outside the agriculture industry.

More and more, we hear about practices to protect soil health and the impact of soil health on the food we eat. Farmers are front and center to these practices and are committed to soil conservation. Afterall, their livelihood depends on healthy soils. Farmers all over the US are now reverting to reduced tilling or no tilling to reduce their impact on the soil.6

Through soil conservation practices, U.S. farmers have reduced soil erosion by 65% per metric ton of U.S. soybean production since 1980 (US Soy Sustainability Practices). Practices to improve soil health are increasingly being adopted but more work remains to be done to improve the impact of farming and farming yields.

In addition, soybeans are a nitrogen fixing crop, meaning that with the help of bacteria, they can fix atmospheric nitrogen from the air and can help increase the levels of nitrogen in the soil when planted in rotation with other crops to help enrich the soil.

Why did we choose soybean protein?

Because it is a high quality plant protein, it is sustainable and because of its great taste.

Although people are increasingly interested in including more plant based meals into their diet, taste remains a serious barrier to trial for the less adventurous among us.

At Soylent, we are committed to make our products taste great. We have a lot of news in store on that front coming soon…

But for now why does soy help us deliver on taste? Soybean protein isolate allows us to provide a taste experience that would be difficult to achieve with other plant proteins such as pea, rice, and hemp.

Soy has a better solubility than other plant protein, allowing for a smooth mouthfeel and a product that stays in solution without gritty deposits. It also has a very light neutral taste reminiscent of cereals whereas other plant proteins have strong grassy, beany, and bitter notes.

Soy also has a light color compared to other plant proteins which again make our drink more approachable to those not into the green juice craze (see picture below from the Soylent Lab).

Different plant proteins in solution

Different plant proteins in solution (from left to right): Soy protein isolate, hemp protein, pea protein, rice protein.

Is soybean protein actually a good source of protein?

Soy protein isolate is a highly digestible complete protein according to widely adopted protein quality measures such as the Protein Digestibility Corrected Amino Acid Score (PDCAAS).

However, this measure does not account for the net effect of proteins on human health or the environment.

Consuming high amounts of high quality animal protein according to the PDCAAS measure goes against the Dietary Guidelines for Americans which recommends the increased consumption of plant foods.

Given this dichotomy between protein quality measures, overall health, and impact of environmental conditions on our health, a new protein quality definition has been proposed.7

This new measure “incorporates the quality of health and environmental outcomes associated with specific food sources of protein” according to the authors.

It also assigns a score to protein based on 3 parameters; the PDCAAS score, if it is recommended by the Dietary Guidelines for Americans, and its environmental impact.

Using this new method, Soy came ahead of all plant protein but also ahead of dairy and other animal protein. This new method is a new concept and not recognized by any regulatory agencies but is a start in the right direction to look at protein quality in more inclusive terms.

Exploding bottle of Soylent mint chocoalte

The Soylent team is constantly looking at new ways to make our products more sustainable and nutrient dense. We have and will always remain committed to using soy for these reasons and proudly support our soy farmers which provide us with the best ingredient we could ask for.

Try any of our soy-based meal replacement drinks, shakes, or snacks by clicking below

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1. Sabaté J., Soret S.. Sustainability of plant-based diets: back to the future, Am. J. Clin. Nutr., Volume 100, 1, 2014,
2. Impact of Soybean Production on U.S. Forest Acreage
3. Forest Resources of the United States, 2012, 2017 
4. 2012 NRCS National Resources Inventory,
5. TRACE 2018 Yearbook.
6. 2017 US Census of Agriculture-
7. Katz DL, Doughty KN, Geagan K, et al. Perspective: The Public Health Case for Modernizing the Definition of Protein Quality. Adv Nutr. 2019.


Julie Daoust, PhD, Soylent VP Product Development & Innovation
Julie Daoust, PhD, Soylent VP Product Development & Innovation