Natural Hygiene on Onions and Garlic

The Jain cuisine is completely vegetarian and also excludes onions, potatoes, brinjals and garlic, similar to the shojin-ryori Buddhist cuisine of Japan.
On the other hand, onions, eggplant and garlic are considered "tamasic" as they are believed to have a quality of darkness, lethargy and a putrid smell.
Strict Jains don’t eat root vegetables such as potatoes, onions, roots and tubers, because such root vegetables are considered ananthkay. Ananthkay means one body, but containing countless lives. 
Strict Buddhist cuisine is similar to Jain cuisine in leaving out onions and garlic. The term satvika often implies Indian cuisine without onions and garlic; strict Jain cuisine also excludes other root vegetables like potatoes.

Natural Hygiene
Also taboo are yogurt, cottage cheese, whole milk, spinach, asparagus, onions and garlic.
Most experts agree that the overuse of salt contributes significantly to cellulite among other conditions, since it tends to cause water retention in the tissues. Thus, avoid adding salt to food, and stay away from those containing generous quantities - canned soups, smoked or processed meats, potato salads, pickles, etc.-as well as flavorings such as celery or garlic salt and the like.
Garlic and onion are undesirable because they contain mustard oil - an ingredient that disrupts the action of certain digestive enzymes. 

What about some herbs that are relished in a raw state, such as garlic, onions, parsley, and so on? In general, these types of herbs are not needed and may prove harmful to the organism. Garlic and onions, two of the most popular flavoring herbs, are full of noxious toxins, like mustard oil and allicin. Parsley is also a strong herb whose use can overstimulate the kidneys. It is a very concentrated green herb which should probably not be a part of the regular diet.
You can read up on what else is said; just wanted to give you a peek.  I know Dr. D wouldn't eat things like onions, ginger, and garlic.  

Forbidden Foods: Mushrooms, Garlic, Onion, and Other “Unnatural” Items
Prominent Natural Hygienist Herbert Shelton rejected all spices, garlic, onion, seaweed, and even mushrooms.
Many Asian health philosophies eliminate garlic, onion and strong spices, finding them too “stimulating.”
Garlic and onion are simply too strong. You could never make a meal out of them. They contain toxic mustard oil that irritates the digestive track.
Garlic, onions and spices are irritants and after a fast a person would not be able to tolerate these irritants.