果食主义（英语：Fruitarianism）是素食主义或纯素主义的一种，主张植物同样具有不可践踏的生命，因此主义实践者只吃植物的果实。果食主义中关于果的定义来自于植物学而非日常用语，也就是说黄瓜、茄子、蕃茄、辣椒等通常不归类于水果的植物学果实是可以食用的。基于各种理由人们选择采取果食主义，包括道德、宗教、环保、文化与健康等等。有些人的当饮食超过75%都是由果实组成便自称为果食主义者。[1]
有些果食主义者只吃会从植物上自然掉落的食物，也就是不用伤害植物就能收割的食物[2][3][4]
，这些食物主要包括水果、坚果与种子[5]。根据作者Adam Gollner，有些果食主义者只吃已经掉落的果实
[6]
。也有一些不吃榖物的人，他们相信这是不自然的作法
[7]。有些人则认为不应食用会长成植物[6]、坚果、种子[8]及水果之前的一切植物的种子[9] [10]
。还有人相信应该只吃会在被吃掉后散播种子的植物[11]。一些果食主义者采用植物学的定义食用包括豆科植物在内的果实。也有包括生果、果干、蜂蜜、橄栏油在内[12]，或食用水果、坚果、种子及巧克力的人[13]。
一些果食主义者为犹太基督徒，根据创世纪第一章二十九节，他们认为果食主义是亚当与夏娃，也就是人类最初的饮食模式。同时他们也相信若要回归一个伊甸园般的乐园，将需要简单的生活与一个完全接纳健康与饮食的方法。[14]有些果食主义者(如耆那教徒)则希望避免杀害包括植物在内的任何生命，而被称为不害的果食主义者。[15]有些果食主义者主张吃植物的果食实际上是帮了它们一个大忙，因为有肉质的果食是演化成适合被动物所食用，借此得以繁衍后代。
在1979年，一名约翰·霍普金斯大学的古人类学家亚伦‧渥克教授(Professor Allen Walker)回报了一项关于原始人类牙齿珐琅质的初步研究，他发现人类祖先的饮食主要来自于果实。这项发现令他感到非常惊讶。[16]
于1971年，一项由B. J. Meyer所主导的短期研究被发表在南非医学期刊(South African Medical Journal)上[17]。内容提到纯果食者其体内的血脂与葡萄糖耐受度都有所进步[18]。根据该研究中更进一步的试验，对于一些过重的试验者在尝试果食法之后，其理想体重有下降的趋势。[19]
一些知名的果食主义鼓吹者，或其饮食习惯被认为是果食主义者包括以下人物：
Sins of the Flesh: A History of Ethical Vegetarian Thought, Rod Preece, UBC Press, 2008, "Since plants have life, it is necessary, if one is not to starve, to live from the fruit of the plant in such a manner that the host plant itself does not die."
Nutrition for the recreational athlete,
Catherine G. Ratzin Jackson, page 95, “The fruitarian diet usually consists of consuming those parts of the plant that are cast off or dropped from the plant and that do not involve the destruction of the plant itself.”, 249 page, CRC Press, 1995, ISBN 0-8493-7914-8, ISBN 978-0-8493-7914-7 Handbook Of Pediatric Nutrition, Patricia Samour, “A fruitarian diet consists of only fruits. Any plant food that is botanically a fruit or can be obtained without killing or harming the plant is considered a fruit." Jones & Bartlett Publishers, 2003, page 143.
'The Fruit Hunters, Adam Leith Gollne, "Some factions eat only fallen fruit. Others refuse to eat any seeds because they contain future plants."
The Ascensional Science of Spiritualizing Fruitarian Dietetics, Dr Johnny Lovewisdom, Ecuador: International University of the Natural Vitalogical Sciences, 1999, Introduction: "Nature is betrayed when man ingests the seeds of plants, depriving them of their means of propagating their own species"; chapter: Sugar & Starch-Friends Or Foes? "grains, nuts and other seeds are wrong as food sources"
"Ascensional Science teaches the damaging effects of chlorophyll leafage, earthly roots and lower passion producing seeds. We are healed by levitational forces in fruit sugars and acids." Introduction to Ascensional Science of Spiritualizing Fruitarian Dietetics, Johnny Lovewisdom, International University of the Natural Vitalogical Sciences, 1999
Food, nutrition, and diet therapy: a textbook of nutritional care, Marie V. Krause, "The fruitarian diet consists of only raw or dried fruits, nuts, honey and olive oil." page 343, Saunders, 1984, Original from the University of Michigan, Digitized Aug 19, 2008, ISBN 0-7216-5514-9, ISBN 978-0-7216-5514-7 Handbook of Sunfood Living: Resource Guide for Global Health, John McCabe, North Atlantic Books, 2008, "other fruitarians also consumer cucumbers, olives, tomatoes, peppers, squash, beans, melon, avocadoes, berries, grapes, figs, dates, carob, chocolate, goji berries, nuts and even coconuts."
"The South African Medical Journal is published by the South African Medical Association, which represents most medical professionals in South Africa.", African Journals Online, http://ajol.info/index.php/samj （页面存档备份，存于互联网档案馆） B. J. Meyer; E. J. P. de Bruin; D. G. du Plessis; M. van der Merwe; A. C. Meyer. Some biochemical effects on a mainly fruit diet in man (PDF). South African Medical Journal. 1971-03-06, 45 (10): 253–61 [2009-11-11]. PMID 5573330. （原始内容存档 (PDF)于2020-10-19）."The effect of a nut-supplemented fruit diet on glucose tolerance, insulin secretion, plasma proteins and plasma lipids was investigated. The results suggest that, at least for the period covered by the experiment and under the prevailing conditions, the diet was adequate with respect to the parameters investigated, and may even have something to commend it." Meyer BJ et al. "Some physiological effects of a mainly fruit diet in man". South African Medical Journal, February 20, 1971; vol. 45, pp. 191-5. "An interesting aspect of the diet was the tendency for the weights to level off more or less at the 'theoretically ideal' weight for the subject."
Goline, Adam Leith (2013) The Fruit Hunters: A Story of Nature, Adventure, Commerce and Obsession New York: Scribner ISBN 9781476704999. Quote: "Idi Amin, the tyrannical Ugandan dictator, lived his final years in Saudi Arabia as a fruitarian (his affinity for oranges earned him the nickname "Dr. Jaffa")." Mahatma Gandhi, Desai, Valji Govindji (trans.)"Tolstoy Farm III" （页面存档备份，存于互联网档案馆） in Satyagraha in South Africa ~ XXXV. Quote: "[D]uring five years of a purely fruitarian life I never felt weak, nor did I suffer from any disease". Autobiography: the story of my experiments with truth, Social Sciences Series, Mohandas Gandhi, Gandhi (Mahatma), Mahadev Haribhai Desai, Dover, 1983, p. 318. "Dr. Jivraj Mehta treated me. He pressed me hard to resume milk and cereals, but I was obdurate."
Gokhale's Charity, My Experiments with Truth, M. K. Gandhi.
Salubrious Living (Creativity Book Publishers, 1982, and World Church of Creativity, 2003), chapter 'The Fruitarian Diet': "The fruitarian diet is composed of the products of the plant kingdom which are delicious and appealing to our taste in their natural uncooked condition. As fruits, vegetables and nuts are the foods which meet this qualification in an ideal manner they are the primary foods used by the fruitarian."
"Steve Jobs" by Walter Isaacson. "Finally Jobs proposed Apple Computer. 'I was on one of my fruitarian diets,' [Jobs] explained." p. 120. "She just wanted him to be healthy, and [Jobs] would be making weird pronouncements like, 'I'm a fruitarian and I will only eat leaves picked by virgins in the moonlight.'" p. 68.
