One of the most prevalent fears and concerns for a new and inexperienced frugivore will be whether or not a low fat fruit and vegetable based diet contains enough protein to thrive on. Because the meat and dairy industries have been so successful at marketing their products, and also because the average human cannot conceive of a diet lacking in "heavy" foods, the protein issue occupies a far greater place in discussion than it actually deserves.
In a natural setting, dwelling amongst trees and plants, foraging for food, and seeking out the ripest fruits and vegetables, there would be no time or reason to ever conceive of or worry about such an issue. Consider the great apes, like the orangutan, or the chimpanzee, thriving on a diet of fruit and veggies, strong and powerful, never concerning themselves about protein. It is only because we live in an artificially constructed world, where diets are analyzed in laboratories and nutrition has become a science, that it is even possible to "create" the issue and become anxious about it.
For millions of years, humans and their ancestors have survived and thrived without concerning themselves with the amino acid profiles of their diets. The primary importance for them was always, and will always be, obtaining a sufficient number of calories to meet the body's energy needs each day, week, month, and year. Because the frugivore diet is the most nutritionally adequate diet one can consume, as long as calorie needs are met, protein will be in the appropriate range.
Because humanity no longer lives in this manner, it is a good idea to be prepared to address this issue when it arises in ones own mind, or when concerned friends and acquaintances bring it up.
A common sense look at the issue will allay any fears. Protein is built from amino acids. There are 20 types of amino acids in total, and these 20 amino acids are the building blocks of every type of protein found anywhere in nature, in any living creature in existence. So in order for the human body to obtain sufficient protein for the maintenance and reconstruction of tissue, and to perform various metabolic needs, a supply of all 20 amino acids must exist.
Plants can generate all 20 amino acids from the carbon, nitrogen, sulphur and water that they obtain from the air and soil. Animals, on the other hand, can only generate some of the amino acids. The rest must be consumed through eating. Human beings can generate 12 of the necessary amino acids on our own, meaning that only the 8 remaining amino acids must be eaten in our food. Fortunately, all fruits and vegetables contain an ample supply of these amino acids. Eating a diet that meets ones calorie needs, consisting of whole, fresh, ripe fruits and vegetables, one will never experience alack or deficiency of any one of the 8 essential amino acids.
How much protein do humans need, day to day, as a percentage of calories? The macro-nutrient ratio of human breast milk gives us a clue. Breast milk is consumed during the time of greatest growth and physical change that a human will ever experience. An infant can double, triple, or even quadruple in size during the first year or two of life. And yet during this time of greatest physical growth, it thrives on a diet of breast milk, which is only 6% protein by calorie!
It cannot be more clear: if, during the time of greatest growth and physical change, the body only needs 6% protein, then 6% or LESS will be more than sufficient for a human adult, who is no longer growing but is merely maintaining . Studies have shown that human beings can thrive on protein intake even as low as 2.5% of calories, and the World Health Organization (WHO) has long considered that 5% is ample.
In fact, fruits and vegetables, on average, are 3-5% protein by calories. This is no coincidence, but rather a reflection of the fact that these foods are perfectly aligned with human physiology and digestion. Consuming other foods, especially animal foods, in an attempt to subvert nature and obtain more than 5% protein can seriously damage health, and result in toxemia and cancer. Excess protein consumption is not healthful, and the liver is forced to break it down and excrete it through the kidneys. The resulting toxicity and strain on the body leaches calcium and is a leading cause of arthritis, osteoporosis, autoimmune disorders, and faulty liver and kidney function.
When a sober look is taken at the issue, unobscured by hype and trendy diet gurus or ideas or industry propaganda, it becomes clear that there never was a protein issue, and that plants easily and optimally provide all of the protein that the human body could ever need. The attachment and emotion that people have wrapped up in their meat and milk and cheese can cause fear and panic when they see someone else (a frugivore) thriving without them. Remaining calm and analyzing the issue clearly will help to alleviate any fears a new frugivore might have, especially in the face of the massive societal pressure attempting to create doubt and fear regarding the sufficiency of the frugivore diet.