This section is from the "Health and Survival in the 21st Century" book, by Ross Horne.
Obviously some fruits are more nutritious than others, and quality will vary according to the quality of the soil in which they are grown. Commercially grown fruit may contain various levels of insecticide poisons, in which case the fruit should be carefully washed or peeled. At the time of writing, the author had subsisted almost entirely on commercially grown fruit for ten years, all the while working long hours under stress seven days a week, and has maintained excellent health. I have chosen the fruit at random with a preference for tropical fruits, and included dried fruits from time to time without any attempt at being scientific about it. It is probably best not to mix the acid fruits with others eaten at the same time. Some people find they experience digestive upsets when at first they embark on a fruitarian diet. This may be because of mixing incompatible fruits or possibly not chewing them properly. The fruit should be taken as snacks throughout the day, as frequently as desired, rather than conventionally as three substantial meals.
If cooked food is eaten at the same time as fruit, the fruit should be eaten first as it digests quickly and clears out of the way of the other food, which may reside in the stomach for several hours.
It is claimed by some people that a fruitarian diet will eventuate in high blood triglycerides and this is why Nathan Pritikin limited fruit. The increase in triglycerides is supposed to follow elevated levels of blood sugar after eating fruit, but this does not occur when eating whole raw fruit, particularly eaten at whim throughout the day rather than in three large meals. An objection to acid fruits such as citrus and pineapples, particularly if unripe, is that, eaten in excess, the acid may cause erosion in the enamel of the teeth. It is interesting to note here that with good body chemistry and a clean mouth, teeth, like bones, are to a great extent self-repairable. With half my teeth jammed with fillings, maybe they are beyond self-repair, but at my yearly pilot medical checkups I enjoy being told by my doctor I have the arteries and blood pressure of a schoolboy. That makes fruit taste better still, even on a winter's day.
A convert to fruitarianism was the Indian philosopher and statesman Mahatma Gandhi, who after experiencing poor health throughout his youth became a student of nature cure at the age of thirty-two. First he became a vegetarian and then a fruitarian. After six months as a fruitarian, he said (quoted from his book Gandhi's Health Guide ):
"A period of six months is all too short to arrive at any definite conclusions on such a vital matter as a complete change of diet. This, however, I can say, that, during this period, I have been able to keep well where others have been attacked by disease, and my physical as well as mental powers are now greater than before. I may not be able to lift heavy loads, but I can do hard labor for a much longer time without fatigue. I can also do more mental work, and with better persistence and resoluteness. I have tried a fruit diet on many sickly people, invariably with great advantage. My own experience, as well as my study of the subject, has confirmed me in the conviction that a fruit diet is the best one for us."
The Japanese soldier who lived wild in the jungles of the Philippines all those years lived on a natural diet and escaped the degeneration awaiting him back in Japan. In Chapter 3 there is a comparison of the Hunza diet with the Western diet; for a comparison of the jungle diet with the Western diet, refer to the table immediately below:
Natural Diet Western Diet Kilojoules (calories) for adult male (approx.) 8400 (2000) 14,700 (3500) Vitamin C (approx.) 3000-9000 mg 100 mg Other vitamins and minerals adequate ? Natural enzymes ideal almost nil Protein % (approx.) 4% (ideal) 15% (hazardous) Fat % (approx.) 4% (ideal) 40% (dangerous) Natural carbohydrate % (approx.) 92% (ideal) 5% (inadequate) Refined carbohydrate % approx.) nil 40% (dangerous) Cholesterol almost nil 10.4 mmol/l (dangerous) Fiber adequate inadequate Salt and condiments nil hazardous Caffeine in tea, coffee, soft drinks nil hazardous Preservatives nil hazardous Heat damage to food nil hazardous Chemicals nil hazardous
From this comparison it can be seen that notwithstanding the Hunzas physical excellence when compared to ours, they still could have done a lot better!