Vegan: Mathematical Proof That Humans Are Herbivores

Going Vegan – Are humans herbivores or omnivores? Is the animal agriculture industry destroying the planet? Can climate change be reversed through vegan and plant based life diets? Near the end of the article I give my mathematical proof that humans are herbivores, with the evidence and sources before.

Enjoy the read.

4.13 billion hectares of land used for animal agriculture

Going Vegan – 75% (3.1 billion hecatres) less farmland needed

Plant-based (vegan) diets reduce food’s emissions by up to 73% depending where you live. Perhaps most staggeringly, we would require ~3.1 billion hectares (76%) less farmland. src

2.3 Billion People (30% of global population) Lack Year Round Access To Food

On other measurements too, the year 2020 was sombre. Overall, more than 2.3 billion people (or 30 percent of the global population) lacked year-round access to adequate food: this indicator – known as the prevalence of moderate or severe food insecurity – leapt in one year as much in as the preceding five combined.

3 Billion Adults and Children Locked Out of Healthy Diets Due to Costs

A full three-billion adults and children remained locked out of healthy diets, largely due to excessive costs. Nearly a third of women of reproductive age suffer from anemia. Globally, despite progress in some areas – more infants, for example, are being fed exclusively on breast milk – the world is not on track to achieve targets for any nutrition indicators by 2030. src

9.9% of the world undernourished

Disturbingly, in 2020 hunger shot up in both absolute and proportional terms, outpacing population growth: some 9.9 percent of all people are estimated to have been undernourished last year, up from 8.4 percent in 2019.

World Wide Obesity (1.9 billion adults)

Some recent WHO global estimates follow.

  • In 2016, more than 1.9 billion adults aged 18 years and older were overweight. Of these over 650 million adults were obese.
  • In 2016, 39% of adults aged 18 years and over (39% of men and 40% of women) were overweight.
  • Overall, about 13% of the world’s adult population (11% of men and 15% of women) were obese in 2016.
  • The worldwide prevalence of obesity nearly tripled between 1975 and 2016.
What are common health consequences of overweight and obesity?

Raised BMI is a major risk factor for noncommunicable diseases such as:

  • cardiovascular diseases (mainly heart disease and stroke), which were the leading cause of death in 2012;
  • diabetes;
  • musculoskeletal disorders (especially osteoarthritis – a highly disabling degenerative disease of the joints);
  • some cancers (including endometrial, breast, ovarian, prostate, liver, gallbladder, kidney, and colon).

Land Needed For Protein Growth

The land use of livestock is so large because it takes around 100 times as much land to produce a kilocalorie of beef or lamb versus plant-based alternatives. This is shown in the chart below. The same is also true for protein – it takes almost 100 times as much land to produce a gram of protein from beef or lamb, versus peas or tofu.

Vegan / Plant Based Diet Reduces Emissions and Water Needs

Specifically, plant-based diets reduce food’s emissions by up to 73% depending where you live. This reduction is not just in greenhouse gas emissions, but also acidifying and eutrophying emissions which degrade terrestrial and aquatic ecosystems. Freshwater withdrawals also fall by a quarter. Perhaps most staggeringly, we would require ~3.1 billion hectares (76%) less farmland. ‘This would take pressure off the world’s tropical forests and release land back to nature,’ says Joseph Poore.

Earths Surface, Habitable Land, Agriculture Land

Of the 71% of habitable land:

50% agriculture, 37% forests, 11% shrub, 1% urban, 1% fresh water.

Of the 50% agriculture land, 77% is livestock.

Of the 77% livestock farming, only 17% of our caloric supply is created. 83% from plant based foods caloric supply comes from 23% of the crops land dedicated to plant based foods.

Protein supply from the numbers above:

33% for meat and dairy vs 67% from plant based foods.

Growing Population: By 2050 2-3 billion more people to feed.

There are a couple of considerations to take into account. Firstly, although we expect yields to increase—particularly in countries with strong economic growth—global population is also growing; by 2050 we will have a further 2-3 billion people to feed. In order to spare land from crop production, yields therefore need to increase at a faster rate than population growth. src

Adequate Caloric, Protein, and Macro Nutrient Intake

The average caloric intake world wide is 2,180 kcal per person per day src

Recommended daily value of protein is .80 grams per kilo of bodyweight or .36 of pounds of body weight for a sedentary lifestyle. src

175(lbs) x .36 = 63 grams daily

Protein Requirements

About 50 grams, or about 15% of your calories, is enough daily protein for the average adult to meet basic needs. But I say eating as much as a third of your daily calories from protein (about 112 grams) is both safe and beneficial. src

Going Vegan: Mathematical Proof

In order to create an equation for something like this, you have to have variable inputs. I am listing the variable inputs below:

Doing the math (creating variables)

If the Earth is 29% Land

And 71% is habitable

And 50% of that land is used for agriculture

While Also

3 billion adults locked out of healthy diets

10% (estimated) are undernourished

24% (1.9 billion) are overweight

While Also

Protein Requirements:

between .36 (basic needs), .50 (health), 1:1 (muscle building).

Average protein consumption world wide: 68 grams

Average Caloric Intake world wide: 2.1k

2-3 billion more people to feed by 2050 (increasing caloric and protein intakes).

100x as much resources to produce a kilocalorie of beef.

Other Considering Factors:

3.1 billion hectacres less farmland needed (vegan / plant based).

Fresh water withdrawals 25% less (vegan / plant based).

73% reduction in emissions (vegan / plant based).

72 billion animals are killed for meat every year

Creating a Proof

7.9 (estimated) billion people in the world

7.9 billion – 10% = 790 million (undernourished – starving)

7.9 billion – 30% = 2.370 billion (inadequate food supply)

7.9 billion – 24% = 1.9 billion (obesity) Obesity is a form of malnutrition

Adding up all of these you get est. 5 billion (starvation, malnutrition, obesity)

3 billion people locked out of healthy diets src

between 3 and 3.16 billion people lack proper nutrition (excluding obesity)

To eliminate global hunger and starvation we should focus on solving all of these forms of malnutrition.

3 billion people need at least 25 additional (new) sources of protein

If 3 billion people lack adequate caloric and macro nutrient intake, our protein consumption would need to increase by 75,000,000,000 (seventy five billion)
3 billion * 25g protein = 75B grams of protein

The above calculation assumes each person would need 25 new grams of protein if they were getting very little protein at all.

A gram of protein contains 4 kilocalories

If only 10% (790m) of the population need additional (new) sources of protein

If only 10% of people needed new calories of protein this would equal

19,750,000,000g of protein

How much protein is in a whole cow?

Your average steer is going to provide somewhere between 740# and 770# per carcass and the meat is going to be around 490#. You should get about 127.4# of protein from an average steer. 1 gram of protein is worth 4 Calories.

“Most mature cows in mid-gestation will need about 1.5 pounds of protein per day. In late gestation they probably require closer to 2 pounds per day. When lactating, their requirements are even higher and will vary depending on the level of milk production,” she says. src

127 pounds * 453 g (per lb) = 57,531 grams p per cow.

127.4 lbs * 453.59 g/lb * 4 Cal/g = 231,150.67 Calories.

How much protein do cows need?

“Most mature cows in mid-gestation will need about 1.5 pounds of protein per day. In late gestation they probably require closer to 2 pounds per day. When lactating, their requirements are even higher and will vary depending on the level of milk production,” she says.

Every day a cow needs between 1.5 to 2 pounds of protein per day.

It takes a cow 32-42 months for a cow to reach slaughter weight.

960 days * 1.5 = 1,440 pounds of protein to receive 127 pounds of meat.

Beef is 11 x more inefficient for protein

Land Use

119(m2) acres per 1000 kilo calories for beef vs

2.19(m2) acres per 1000 kilo calories for pea

Beef vs Pea (for meat) is 55x more inefficient.

Water Use

A single pound of beef uses 1,800 gallons of water

39 gallons of water to grow a pound of vegetables


36 KG Co@ emission per kilogram of beef2

2.00 kg CO2 emission per kilogram of food.

Pulling It All Together

I will leave all the variables here and see if someone else can create a proof – a proof being eating animals is unsustainable (proving humans to be herbivores).

There is a theoretical amount of protein the average person needs to maintain a healthy body.

If you multiply the amount of protein we need to maintain a healthy weight, by the water, time, land and resources it takes to yield animal products, eventually you will hit a limit on the avaialbity of resources to produce adequate amount of food to feed people.

Thus, based on math, not only is eating meat inefficient, it means humans are herbivores!


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