for committed sins but also as a means to prevent excessive eating and drinking. The duration of fasting may vary from a few hours during the day (e.g., from sunrise to sunset for Jews), to a fixed number of hours (e.g., 12‐24 hours or more for Catholics, Greek Orthodox, and Mormons whose fasting is practiced on specific days), but also for several successive days, as happens during the Ramadan month for Muslims.
Detailed descriptions of the following religion‐based dietary models and their corresponding sample menu plans can be found in Appendices B.4.‐B.8.
Buddhism
“Do not kill or harm living things” is the first of five basic precepts of Buddhism. Thus, the majority of Buddhists abstain from meat consumption, and all of them exclude beef products from their diet. The major religious events for Buddhism are the birth, the enlightenment, and the death of Buddha; on these days devotees do not work but spend their time celebrating and fasting. Buddhist monks undergo complete fast depending on the moon phase, and they refrain from solid food intake after noon.
The life of a Buddhist encompasses many other lifestyle factors that have been shown to improve health. For example, Buddhists practice meditation and yoga, activities that have been shown to cause favorable health effects. Meditation has positive effects on reducing stress and increasing mindfulness, as well as improving BP and vascular endothelial function. Numerous studies have demonstrated the role of mindfulness‐based stress reduction in T2DM, showing modest improvements in body weight and glycemic control. Even short‐term engagement in yoga practice has been found to improve obesity, CVD, and T2DM risk factors among high‐risk populations.
Key Point
The life of a Buddhist encompasses many other lifestyle factors that have been shown to improve health status.
Hinduism
Fasting, known as Vrat or Vratam, is fundamental to the Hindu religion. It denotes the denial of the body's physical needs in favor of mental health. Each day in Hindu religion is devoted to a particular deity, and based on personal choice, believers can fast or not. Tamasic foods, such as fish and meat, are usually avoided for several days. During fasting, Hindus usually avoid solid foods and follow a liquid diet with vegetable or fruit juices. A stricter fasting ritual also exists, avoiding any solids and any form of liquid but water. Hindus follow fasting practices on each of the 18 major Hindu holidays but also on such days as birthdays, anniversaries, deaths, and marriages. Sunday is also a fasting day, as are certain days relative to the planetary scenery, i.e., the position of the moon and the planets.
Key Point
Fasting, known as Vrat or Vratam, is fundamental to the Hindu religion.
Although meat consumption is allowed in nonvegetarians, meat products such as those derived from pork, fowl, duck, snails, crabs, and camels are not preferred, as animals are considered part of the chain of life and should be treated with compassion. Because cows are considered sacred animals, beef intake is prohibited; however, the consumption of dairy products derived from cow, such as milk, yogurt, and butter, is allowed as they are considered to be pure and to contribute to the purity of body, spirit, and mind.
Judaism
In Judaism, believers consume only what is considered to be kosher, i.e., whatever has been prepared in agreement with the dietary regulations of Kashrut. Kashrut, which means “proper” or “correct,” is a set of dietary laws determining the foods that Jews are permitted to eat and how they should be prepared. These laws are spelled out in detail in the written Torah, Leviticus 11. The dietary laws have the added benefit of preventing contamination and improving health. For example, Kashrut defines the proper handling of kitchenware, determines that the only types of meat that may be eaten are cattle and game that have “cloven hooves” and “chew the cud” (e.g., sheep, cattle, goats, and deer), notes that kosher and nonkosher foods cannot be served in the same plate, and states that meat and dairy products should be separated. After meat meals, one must wait several hours before eating dairy. However, after dairy consumption, no interval is required before meat may be eaten.
Key Point
Kashrut is a set of dietary laws determining the foods that Jews are permitted to eat and how they should be prepared.
The Jewish calendar has comparatively few days of fasting. Besides the Day of Atonement (Yom Kippur), which is the only fast day prescribed by the Mosaic law, there are only four regular fast days in commemoration of various historical events. Fasting lasts from sunrise to sunset, and the participants abstain from all food and drink, including water.
Islam
Halal (permissible) and Haram (forbidden) are the main concepts of Islamic dietary laws and are used to designate what is lawful to be eaten and what is prohibited for Muslims. Foods whose consumption is ambiguous are called Mashbooh. Muslims must follow these laws and never disobey irrespective of their age, sex, and caste.
The dietary laws of Islam have many similarities with dietary laws of Judaism. The followers of Islam eat foods that purify their body and spirit from all kinds of dirt and impurities, based on what Allah commands. For example, all kinds of birds are permitted expect for prey birds. In Islam, all kinds of vegetables, fruits, and crops that are not contaminated are allowed. Animal meat is lawful for consumption when it has been properly slaughtered, except for meat that is specifically forbidden (e.g., pork). The prescribed method of ritual slaughter of all lawful halal animals is called Dhabihah.
Key Point
The followers of Islam eat foods that purify their body and spirit from all kinds of dirt and impurities.
Islam discourages overconsumption of food and the intake of stimulants (such as coffee, tea, alcohol). Muslims fast on Mondays and Tuesdays and for a 6‐day period during the 10th month of the Islamic year, named Shawwal. However, their most renowned fasting period is the holy month of Ramadan, the ninth month according to the Islamic calendar. During Ramadan, Muslims do not eat or drink anything from sunrise to sunset, approximately 13–18 hours/day.
Ramadan fasting has been associated with weight loss, attenuation of several metabolic markers (such as insulin resistance, high blood glucose, and high BP), improvements in lipid profile, prevention of chronic diseases (such as obesity, diabetes, CVDs, and cancer), and protection against neurodegeneration and inflammation. However, the results from the Epidemiology of Diabetes and Ramadan (EPIDIAR) study, which included patients with T1DM and T2DM, suggested that fasting during Ramadan can result in an increased number of hypoglycemic episodes. Education on diabetes management and medication adjustments prior to Ramadan has been shown to help overcome these problems.
In a systematic review and meta‐analysis of 70 publications with a total of 2947 subjects, a significant reduction in body fat was found between the pre‐Ramadan and post‐Ramadan period, but only in overweight or obese individuals. However, a significant loss of fat‐free mass (i.e., muscle and bone) was also found between pre‐Ramadan and post‐Ramadan. Nevertheless, 2–5 weeks after the end of Ramadan, weight and body composition returned to pre‐Ramadan levels, as is the case when any kind of diet based on caloric restriction is discontinued.
Christianity
