I want to guarantee an easy, effective, and possibly free food source for the rest of my days, but I am skeptical.

Growing my own organic food would be ideal, but that would limit my mobility or require that I rent/own land. I apologize in advance for my ignorance in terms of nutrition and science. So here it goes:

Can I train my body to survive by relying mainly on grass or leaves as a food source? Has anyone ever successfully pulled this off?

I am not sure what a reliable source would be for such a question, but I have seen, to some extent, positive and negative answers to this question.

Follw Up: If the answer is negative, what's the easiest way to satisfy to satisfy my nutritional needs in a safe way? By easiest I mean 1) requires no land, little time or effort, 2) easy access, 3) doesn't make one sick, and 4) inexpensive or free.

  • "It is said that the Dragon Warrior can survive for months at a time on nothing but the dew of a single ginko leaf and the energy of the universe." Tigress from Kung Fu Panda...
    – ABcDexter
    Jul 9 '16 at 10:11
  • Define "survive." Yeah, you could survive for a while eating whatever free and edible plant matter you could find, but your health would deteriorate and eventually you would become ill from nutritional deficiencies. Leading a healthy vegan lifestyle takes a bit more thought than eating whatever's growing in the yard.
    – Carey Gregory
    Jul 9 '16 at 14:11

Your body needs energy and unlike cattle, horses and other herbivores, humans cannot derive energy from grasses. That is because our body cannot break down cellulose (a polysaccharide that makes up the cell wall of plants and is the main energy source for herbivores).

Cellulose, like starch, is a carbohydrate made up of glucose monomers. You cannot digest cellulose but you can digest starch which is one of the main sources of energy for humans.

Coming back to your question:

Can I Survive on a Mostly Grass/Leaf Diet?

No. It is not really implementable. Some leaves (like spinach) are rich in certain nutrients but you need a primary energy source. Though fats also provide energy, carbohydrates cannot be replaced because the intermediates of glycolysis i.e. breakdown of glucose (which in turn comes from carbohydrates like starch), are essential for many other vital processes in the body (such as DNA synthesis). There is a biochemical pathway known as gluconeogenesis which can produce these intermediates from amino acids and certain fats (fatty acids with odd number of carbon atoms in the side chain). Leaves won't provide these as well, in sufficient amounts.

Finally you need proteins which is again poor in leaves. Herbivores consume a lot of food to meet their metabolic needs. Have a look at this post in Biology.SE. Our digestive system is not really tuned for this kind of a job.

If the answer is negative, what's the easiest way to satisfy to satisfy my nutritional needs in a safe way?

This is a broad question and is also subjective. It depends a lot on the geography of your surroundings, your specific metabolic makeup etc.


Welcome for human being 6 types of needed almost everyday. Among them carbohydrates,protein and Fat we consider first, Others vitamins, minerals and water. Carb or carbohydrates mostly comes from sugar like sweet,rice,wheet etc, It is imp. Cause it gives ready energy through ATP,and carb is only food for our brain. Next protein that mostly comes from anemel source partly vegetable source, It develop our body and growth next fat that also come from anemel source and some from veg.oil.It acts as a reserve energy. Other 3 elements comes from both source and also imp but need limited amount.So, your plan is possible but really hard.

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