Table 1. [Part 1]. PRISMA Checklist.

Section/Topic	#	Checklist Item	Reported on Page #
Title
Title	1	Food Reduction in Avicenna’s View and related principles in classical medicine	1
Abstract
Structured summary	2	Background: Traditional Iranian medicine (TIM) is a rich and valuable school of thought that believes medications are not the only effective approach for the treatment of diseases but that nutrition is also important. Data sources: Our study includes two parts: the first is a book review of the Canon of Medicine by Avicenna (10th and 11th centuries), in which we focus on finding and understanding Avicenna’s point of view. In the second part, we searched for “food reduction” as a key word from 2000 to 2015 in databases such as Google Scholar, PubMed, Copernicus, DOAJ, EBSCO-CINAHL, and the Iranian search database Iranmedex for principles of food reduction in classical medicine. Results: The main methods of treatment in traditional medicine include changes in lifestyle, especially diet, the use of medications, and the use of manipulation methods. For diet, the individual may be prohibited from eating or the amount of food may be decreased or increased. Centuries ago, Avicenna was making use of methods of food reduction as an important therapeutic approach in the treatment of diseases. According to him, food reduction, to the extent that it does not cause energy loss, helps to cure disease. Avicenna has proposed food reduction as an aid to treating a variety of ailments such as headaches and reflux. Conclusion: Today, a variety of basic and clinical research has shown that food reduction or calorie restriction to a standard level can prevent and treat a variety of diseases effectively such as neoplasms, diabetes and kidney disease.Practical principles explained by traditional Iranian medicine, in particular Avicenna, could open important and quite uncomplicated strategies in the prevention and treatment of diseases. Keywords: Avicenna; Traditional; Medicine; Iran	2
Introduction
Rationale	3	Traditional Iranian medicine (TIM) is a rich and valuable school of thought that believes medications are not the only effective approach for the treatment of diseases but that nutrition is also important.	2
Objectives	4	Our study aims to introduce a cost-effective method with few if any side-effects for preventing and treating diseases.	3
Methods
Protocol and registration	5	We searched for the term “food reduction” and selected articles explaining the principles and mechanisms of its effects.	4
Eligibility criteria	6	We searched from 2000 to 2015 for human studies discussing the principles of food reduction.	4
Information sources	7	Google Scholar, PubMed, Copernicus, DOAJ, EBSCO-CINAHL, Iranmedex	4
Search	8	We searched for “food reduction” between 2000 until 2015 in Google Scholar, finding 1220 articles. We then selected only articles in English, of which there were 87. Some of these articles were not related to our study, so we selected only those in which principles of food reduction were described, which numbered 17. Finally, articles without a PMID or DOI number were discarded, leaving 15 articles. In DOAJ we searched for “food reduction,” which first resulted in 7389 articles. We then selected articles with the subjects “Nutrition, food and food supply,” of which there were 859. Of these, we selected those in English and in food and nutrition science, leaving 56. However, we did not find any articles about the mechanisms and principles of food reduction that we could use in our article. The same thing occurred using Iranian databases, for example in Iranmedex we found 19 articles about food reduction from 1380, but they were not compatible with the concept of our article and we could not use them in our article.Because of this we only mention results from Google Scholar and Pubmed in our article and we do not discuss the other databases, but we now mentioned the other results in our article as above.	4
Study selection	9	Refer to item 8	4
Data collection process	10	Refer to item 8	4
Data items	11	Refer to item 8	4
Risk of bias in individual studies	12	All articles were reviewed twice by one reviewer.	4
Summary measures	13	Refer to item 8	4
Synthesis of results	14	Refer to item 8	4