Let's admit it - we're all pretty high-rate consumers, and our choices constantly affect not only us, but the environment at large. And there's only so much we can do to limit the negative impact on our planet before succumbing to 'green fatigue' when it all just gets way too overwhelming.

Still, our individual choices do matter, even if the overall contribution is tiny. And, if you're curious about leading a more sustainable lifestyle, you'll be interested in some surprising facts about food and drink we consume nearly every day.

Let's start with one of the world's most valuable crops. You've probably heard that coffee production comes with a slew of associated troubles. Traditionally, coffee used to grow in the shade of trees, boosting biodiversity and preventing soil erosion. But the high-yielding and sun-loving species grown today are contributing to deforestation and require tonnes of water.

According to one regularly cited Dutch study from 2007, a standard cup brewed with 7 grams of coffee in the Netherlands - a coffee-loving country - 'costs' about 140 litres of water. That's the amount of water required for the production of beans that contribute to said cup: from harvest to processing, washing, roasting, and so on.

Meanwhile, a cup made with 3 grams of tea - black, green, or oolong - uses up roughly 34 litres of water. The authors also note that "additional environmental cost of coffee and tea is that coffee and tea plantations often contribute to deforestation, erosion, and river pollution".

However, a water footprint is largely related to economic cost, and these numbers come from calculating the 'virtual' water content of a product, which some experts point out as inadequate for measuring in context with factors such as production methods and local water scarcity.

But we can also look into the carbon footprint of our everyday items, as measured in grams of carbon dioxide equivalent, CO2e. It's also not a dead-precise measurement - because so many individual variables go into our consumption - but it gives you at least some idea of how much your daily caffeine hit is contributing to global warming.

According to carbon emissions expert Mike Berners-Lee, if you make a cup of black tea or coffee and boil only the water you need, that will be 21g CO2e, which is not that bad.

But as soon as you add milk - which comes from methane-belching cows - your hot beverage suddenly becomes a lot less carbon-friendly. "If you make a white tea, filter coffee or instant coffee, and you don't overfill the kettle, then the milk will typically account for around two-thirds of the total footprint - more than boiling the water and cultivating the tea or coffee put together," Berners-Lee writes at The Guardian. Hence a large latte can contribute a whopping 340g CO2e.

Meanwhile, the environmental impact of our food is somewhat more difficult to determine precisely, because it often boils down to macronutrients rather than individual foodstuffs.

As philosophy professor Janet Stemwedel wrote at her Scientific American blog in 2011, "Without specifics about what you're eating, how it was fed or produced, and how much fuel was consumed getting it to you, it's impossible to hold up a kilogram of protein from one source and a kilogram of protein from another and say anything very sensible about which contributes more to global warming."

It might be that tofu is less costly than beef, but then perhaps the cow was grown locally and fed grass, while the tofu was made from processed soybeans and shipped for thousands of kilometres. You'd need a whole lot of data to make sure you're making the most sustainable choice.

This is why it's not worth despairing about your grocery shopping, and why the most sound sustainability advice is to simply eat lower on the food chain - e.g. fruits and vegetables - buy local to eliminate food miles, and buy fresh to avoid the processing steps laden with a carbon and water footprint. Which, incidentally, also makes for a generally healthier diet.