A study came out in 2016 that outlined the carrying capacity of different types of food diets in the US.
With the world population expected to grow dramatically through to 2050 and 2100, this information might be of interest.
In the guide below, we have paraphrased and outlined the relevant information and numbers from the study. You can read the full study at elementascience.org
Summary – Which Type Of Food Diet Can Support/Feed The Most People?
Vegetarian diets have the highest carrying capacity (with some dairy instead of meat), followed by ovo-lactarian, and then vegan diets
The standard american diet, diets with more animal meats, added fats and added sweeteners, and some highly omnivorous diets tend to have lower carrying capacities
However, there are several variables to this, with a big one being the amount of grazing land, and cropland (cultivated, and perennial) that is ultimately available
Livestock can use less fertile land (grazing and pasture land) that plant based food generally cannot, so can make use of a wider variety of land. Vegetables, fruits etc. generally need arable fertile land to be grown in large quantities
You can’t look at the carrying capacity of each type of diet without considering the types of land each diet uses and doesn’t use
A vegetarian diet with some meat included for example may be able to provide food for more people than a purely vegan diet, because the vegan diet can’t make use of grazing land which is more abundant
Food waste, and food yields of each diet are also important variables
How exactly the diet is composed/made up, and in what proportions of each food group, can also influence the final result/numbers for each diet
Proper distribution of food, and food waste/food loss are important considerations in any increased carrying capacity scenario
How Many People Can Each Type Of Food Diet Feed/Support In Society?
The aggregate area available for food production was estimated to be 95 million ha cultivated cropland, 134 million ha total cropland, and 299 million ha grazing land.
Based on that assumption, the total number of people each type of food diet could support/feed would be:
- Baseline/Contemporary American Consumption Pattern Diet – 402 million people, or 130% of the estimated year 2010 population
- Positive Control Diet (as per baseline except intake of fats and sweeteners is reduced to make diet energy-balanced) – 421 million people, or 136% of the estimated year 2010 population
- OMNI 100 Diet (100% of person-meals follow an omnivorous healthy diet pattern) – 467 million people, or 151% of the estimated year 2010 population
- OMNI 80 Diet (80% of person-meals follow an omnivorous healthy diet pattern, and 20% follow a ovo-lacto vegetarian healthy diet pattern.) – 548 million people, or 178% of the estimated year 2010 population
- OMNI 60 Diet (60% of person-meals follow an omnivorous healthy diet pattern, and 40% follow a ovo-lacto vegetarian healthy diet pattern.) – 669 million people, or 217% of the estimated year 2010 population
- OMNI 40 Diet (40% of person-meals follow an omnivorous healthy diet pattern, and 600% follow a ovo-lacto vegetarian healthy diet pattern.) – 752 million people, or 244% of the estimated year 2010 population
- OMNI 20 (20% of person-meals follow an omnivorous healthy diet pattern, and 80% follow a ovo-lacto vegetarian healthy diet pattern.) – 769 million people, or 249% of the estimated year 2010 population
- OVO Diet (Ovolacto vegetarian – Includes both eggs and dairy products.) – 787 million people, or 255% of the estimated year 2010 population
- LAC (Lacto vegetarian – Includes dairy products. Excludes eggs.) – 807 million people, or 261% of the estimated year 2010 population
- VEG (Vegan – Excludes all livestock products.) – 735 million people, or 238% of the estimated year 2010 population
Read the full study if you want to see the full breakdown of how much of each type of land that each type of diet uses, or the food sub groups included in each type of diet.
A Few Notes On Food Diets, Land Use & Carrying Capacity
The different diets use grazing land, perennial cropland and cultivated cropland in different proportions
Some diets don’t use cropland or grazing land at all
Food waste at the consumer level, and crop yields are not taken into account in the above study, and both could change the results
Another study actually finds that higher quality diets that include a lot of plant based food (fruits and vegetables) actually waste less cropland compared to lower quality processed food, sweeteners and animal feed (essentially – the “Western diet”, characterized by high intake of refined carbohydrates, added sugar, sodium, and animal products, and low intake of fruits, vegetables, and whole grains)
Diet composition (exactly what foods are included in each type of diet and in what %’s) is a big variable that could also change results
Since meat consumption is expected to increase in the future, it would be interesting to see what a diet with more animal meat protein consumption looks like from a hectares per person annually perspective, and from a carrying capacity perspective
Different diets are going to have different nutritional profiles – which may suit some, and not suit others
1. Peters, C.J., Picardy, J., Darrouzet-Nardi, A.F., Wilkins, J.L., Griffin, T.S. and Fick, G.W., 2016. Carrying capacity of U.S. agricultural land: Ten diet scenarios. Elem Sci Anth, 4, p.000116. DOI: http://doi.org/10.12952/journal.elementa.000116 – https://www.elementascience.org/articles/10.12952/journal.elementa.000116/#