Every food product has a water footprint i.e. the amount of water it takes to make/produce it.
This guide summarises how it might be possible to decrease the water footprint in the foods an individual eats, by identifying the most and least water hungry foods across different measurements and metrics.
You may also like to read these complementary guides which list the water footprint numbers associated with different food and beverage products:
- Foods & Crops That Take The Most Water To Make
- How Much Water It Takes To Make Common Everyday Products & Foods
(*Note – this guide is general information only. It is not expert advice or a professional opinion. See a professional before making decisions or changes with your health or diet.)
Summary – How To Decrease The Water Footprint With The Foods You Eat
A few general trends to take note of that relate to food water footprint are (based on water usage numbers per weight unit of food produced):
- Generally, vegetarian diets might use less water to produce than meat based diets across different measures.
- When cutting down on animal meat – beef in particular – may be the best place to start, as it appears to have the highest water footprint
- When keeping meat in the diet, eating poultry as opposed to beef, pork and even sheep may lead to a lower water footprint. Eating animal meat from an animal caught in the wild as opposed to one that is factory farmed (and relies on feed from irrigated crops) may lower the negative water footprint. Also, eating meat that is fed from grass that is mainly rainfed, may also lead to a more beneficial water footprint for example
- When cutting out meat, be aware that dairy (milk, butter, cheese, chocolate, etc), and processed foods, can carry the next highest water footprints.
- When cutting out meat and animal by products completely (including dairy), be aware that olives, rice paddy, and certain types of nuts can use moderate to high amounts of water to produce
- Cabbage and lettuce, cucumber, tomatoes, oranges corn and potatoes can be some of the least water intensive foods per unit of weight produced
- In terms of beverages, pure water may be a less water intensive drink to produce compared to beverages like coffee, soda, beer and wine, and fruit juices (as these beverages often require the growing of plants or crops as part of the ingredients).
Any combination of these foods might be eliminated, reduced, substituted or increased to change a water footprint.
However, when talking about per unit of calories, protein, and fat for example (and not per unit of food weight):
- Plant based foods like vegetables and fruits can move much further up the list, either just behind beef, or in line with other meats and dairy in terms of how much water they need
- Fruits and starchy roots are examples of this for per gram of fat and protein measurements
- Beef generally though is high on the list
For a quick comparison table, see this resource (waterfootprint.org)
This is a very simplistic way of looking water footprints and food groups though. There’s many other variables to consider such as other ways to measure water use (per serving, or per dollar of economic output as two examples), the local climate and agricultural conditions that can change water requirements, the different variations of food products (different types of milk or cheese for example), and so on.
It also only takes into account production, but not food waste at the consumer level.
Vegetables, fruits and highly perishable foods are actually wasted at a greater rate at the consumer level than meats for example. They are also responsible for more waste of irrigated water than animal based products.
There are many other things to consider in food products other than just the water footprint. Solely plant based diets are not perfect, do have their own drawbacks, and may not be healthy for some groups of people with certain nutritional requirements and health conditions.
A water footprint has many limitations because it really only shows a rough water volume number. Read more about the limitations of water footprints in this guide.
There’s also the consideration that a high water footprint might not be a bad thing if that water comes mainly from rainfed sources, or from renewable and sustainable water sources. Some people also argue that higher water footprints are also OK as long as they lead to other benefits like the provision of income, employment, and local food production.
Food Groups With Higher Water Footprints
- Animal meat (beef, pork and lamb more than chicken) – one of the reasons why is that growing animal feed takes up a lot of water, and then there’s also water required for farming animals (water the animals drink, and for washing down and servicing farms), water for slaughterhouses, and water that goes into refining fuel for transport – just as a few examples
- Dairy (Milk, Cheese, Butter etc.)
- Some Beverages – coffee, fruit juice, wine and beer, soda
- Some Nuts (peanuts, almonds, walnuts, groundnuts, etc)
- Some plant based foods that are water hungry like olives, dates, rice paddys, and so on
- Generally anything related to meat, animal by product, sugar or being highly processed (processed foods in particular might involve extra stages to process the food compared to natural foods)
There are exceptions to this list though – take for example a naturally hunted animal that doesn’t use up any irrigated water, and relies only on what is available in nature.
Food Groups With Lower Water Footprints
- Vegetables & Pulses
- Fruits (except for some measures such as per gram of protein or fat – where fruits and starchy roots can exceed meat)
- Generally plant based foods
Some individual types of plant based foods though can be much higher in water use than others (such as different types of tomatoes, or different types of nuts), and this may be even more so the case in hot or dry climates.
Notes On Food Water Footprint Variables
The water footprint given for any particular food will vary depending on where/how the food has been produced, what data has been used (and how easily information can be obtained by those putting together the results), and the final unit of measurement used (total weight vs gram of protein vs gram of fat vs per calorie, and so on).
It does depend on the farming method used (for example grain and grass fed beef can have different water requirements), where the food is produced (country, state/province and specific farm) and whether mostly irrigated (more of a threat to water resources as it depletes freshwater sources) or rain fed water has been used (rain fed means it’s less of an issue for water scarcity).
It also depends on which indicator you are measuring the food water footprint by:
- Per serving
- Per unit of weight (pounds, kilograms etc.)
- Per calorie or kilocalorie
- Per gram of protein
- Per gram of fat
- Per gram of carbohydrates
- and more
Different foods have different nutritional profiles, which is a different consideration altogether from food weight or serving amount.
Wasted Food At The Consumer Level, & Wasted Water At The Production Level
You also have to consider food waste – and vegetables, fruits and healthier foods tend to have a higher food waste rate at the consumer level (and therefore their water footprint increases when consumer level waste is taken into account).
- Nearly 4.2 trillion gallons of irrigation water were applied to cropland that was used to produce uneaten food. The majority of wasted irrigation water was applied to cropland used to produce fruits (1.3 trillion gallons), vegetables (1.05 trillion gallons), and hay (1.01 trillion gallons).
- Production of fruits and vegetables wasted in high proportions [and they are compared to other food types] carries environmental burdens … particularly due to relatively high rates of pesticide use and irrigation. Higher quality diets contained greater amounts of fruits and vegetables … [and they] have higher agricultural input needs (per unit of land area) than most other crops
Irrigated water use contributes to freshwater scarcity, whereas rain fed crops tend to be better from a sustainability point of view.
7. Conrad, Z., Niles, M.T., Neher, D.A., Roy, E.D., Tichenor, N.E. and Jahns, L., 2018. Relationship between food waste, diet quality, and environmental sustainability. PloS one, 13(4), p.e0195405. – https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0195405