There is a lot of misinformation out there surrounding vegetarian diets, and unfortunately people that misrepresent themselves only complicate matters further. Let me clear some of that up for you by giving you the standard definitions for diet styles.
Each of the diets on the spectrum below starts with a plant-based diet. Foods typically included in a plant-based diet are fruits, vegetables, nuts, seeds, grains, and legumes.
Category: NOT Vegetarians
People that eat both plants and animals on a regular basis. There are no food restrictions in this diet.
Omnivores who exclude red meat from their diet.
Those who eat a mostly plant-based diet, but also occasionally eat meat/animal flesh. Flexitarians also consume eggs and dairy.
People who eat a plant-based diet and include fish, but not any other kind of meat/ animal flesh. Pescetarians also consume eggs and dairy.
This is the most common vegetarian type and includes people who eat a plant-based diet and also eggs and dairy, but who do not eat meat/animal flesh, nor other by-products from animal slaughter such as gelatin or rennet.
People who eat a plant-based diet and also dairy products, but who do not eat meat/animal flesh, eggs, nor other by-products from animal slaughter such as gelatin or rennet.
People who eat a plant-based diet and also egg products, but who do not eat meat/animal flesh, dairy, nor other by-products from animal slaughter such as gelatin or rennet.
Category: Strict Vegetarians
(pronounced VEE-guns) People who only eat a plant-based diet. Vegans do not consume meat/animal flesh, eggs, dairy, or any animal by-products. Most vegans refrain from eating honey or foods made using animal products (ie. cane sugar whitened with bone char). Although some people are only vegan in diet (also called Total Vegetarians), veganism usually includes an entire lifestyle of avoiding animal products (ie. leather, wool, fur, silk, etc.), products tested on animals, or any product, company, or business where animals were exploited in some way.
People whose diet consists of unprocessed vegan foods that have not been heated above 115 degrees Fahrenheit. Some raw vegans avoid frozen foods as well. A raw vegan diet includes raw vegetables and fruits, nuts and nut pastes, grain and legume sprouts, seeds, plant oils, sea vegetables, herbs, and fresh juices.
Those who eat unprocessed vegan foods with a focus on low-fat, high fiber items. Macrobiotics work towards the principle of balance in their diet, which looks something like this: whole grains (50-60%), vegetables (25-30%), beans (10%), plus some miso and shoyu-based soups, local fruits, nuts, and seeds. Sugar, coffee, and refined oils are avoided. Macrobiotics also recommend eating based on the season and the climate in which one lives.
People who consume fruits, and sometimes nuts and seeds, but who do not consume animal products, vegetables or grains. Fruitarians generally use the botanical definition of fruit so that can include berries, bell peppers, tomatoes, cucumbers, nuts and grains. Some fruitarians will eat only what can be harvested without killing the plant, and do not include seeds which contain future plants. There are several philosophical variations on fruitarianism.
Category: Other Food/Diet Categories
Each of the categories below contain both plant and animal products, and as such these classifications are completely independent of the omnivore/strict vegetarian spectrum. For example, you can have a vegan who eats primarily local foods, and you can have an omnivore who eats primarily local foods; both would be locavores.
Locavores are people who prefer to buy and eat locally grown and locally produced foods. The USDA suggests that the actual maximum distance under which 'local' can be reasonably or ethically defined is 400 miles.
Organic Certified Foods
Plant foods that are grown with minimal to zero use of non-organic pesticides, insecticides, or herbicides. However, some non-organic fertilizers might be used. Organic produce may not be genetically modified. Animals are raised for food without the use of growth hormones or antibiotics, and are generally supposed to be fed a healthy diet. Processed organic foods must contain 95% organic foods to be considered organic. However, the labeling of organic food grown outside of the US and imported in is based on the farmer's word.
Additionally, organic does not necessarily mean humanely-treated animals.
Related to Organic Foods:
Egg Carton Labels: A Brief Guide to Labels and Animal Welfare
A Brief Guide to Meat and Dairy Labels and Their Relevance to Animal Welfare
What about "Free-Range?"
The Truth Behind The "Humane" Label
Fair Trade Certified Foods
Fairtrade is about better prices, decent working conditions, local sustainability, and fair terms of trade for farmers and workers in the developing world. Foods that are fairtrade certified are generally exports from developing countries to developed countries (ex. bananas, coffee, chocolate, sugar, etc).
Food that is prepared and sourced in accordance with Jewish dietary laws, whose intepretation can be complicated and variable among different groups of the Jewish faith. Kosher foods are often labeled with symbols such as a "K" or a "U" with a circle around it. Foods not sourced from dairy or meat are labeled with the word "Pareve". However, pareve foods are not necessarily vegetarian or vegan foods because fish, eggs, and other animal products are considered pareve. Pareve is also spelled parve. Kosher dietary laws regarding slaughter are not more humane than standard practices.
Humane Kosher- Watch the video, If This Is Kosher...
A Case for Jewish Vegetarianism
Food that is prepared and sourced in accordance with Islamic dietary laws. This is very similar to the kosher food system. While stores and restaurants are increasing their halal options, halal foods are not very common in the U.S. just yet. These food products are commonly indicated with an "H" surrounded by the words "Muslim Consumer Group" (or "MCG")inside of a triangle. Halal dietary laws regarding slaughter are not more humane than standard practices.
So, there you have the most common dietary types and food categorizations that involve a plant-based diet. Keep in mind that individual diets can still vary greatly within each category due to allergies, food availability, belief systems, and food preferences. It is my hope, of course, that everyone work toward a vegan diet and a compassionate lifestyle.