While being a vegetarian does not automatically ensure great health (due to misinformed choices such as eating highly processed pasta dishes and loads of nuts), a diet high in a VARIETY of vegetables and fruits is recommended by the American Heart Association, the American Cancer Association, and the Physicians Committee for responsible medicine.
There have been numerous studies on the effects of many low macronutrient (proteins, carbs, and fats) diets. While many diets result in desired weight loss, it is simply due to the fact that the calorie intake has been cut by 1/3 of what the average American diet provides daily. This simply reiterates the fact that cutting calories results in weight loss.
A study published in 2002 and funded by the Atkins Center for Complimentary medicine concluded in 6 months the 51 participants in the study focused on limiting carbs of any form (including vegetables and fruits) lost an average of 20 pounds. This was largely due to the cut in overall calories. Another thing the participants lost was their hair. 10% of the participants in this study had noted hair loss and all the dieters had a 53% increase in the calcium excreted in their urine, denoting bone mineral loss.
In contrast, the ongoing studies related to a healthy consumption of a VARIETY of fruits and vegetables have been promising. Vegetable based diets have been show to decrease the risk of certain cancers and heart disease (which is why it is promoted by those agencies). Data from NHANES study also reported that by simply increasing ones daily intake of fruits and vegetables they can lower their stroke risk by 27%.
So, with all of these health benefits, does a diet not relying on animal protein cause hair loss? You can get adequate amounts of hair building and protecting proteins from plant sources. Think of the strongest animals on Earth: the gorilla, the hippo, and the rhino...all vegetarians. A vegetarian diet can be fortified with plant based protein powders such as hemp and brown rice, and some vegetarians add eggs and milk to their diets a few times per week.
The key to radiant health and beauty, as well as lustrous hair, is eating a VARIETY in any diet. If vegetarian fair makes you feel grant, try different sources full of protein, such as kale, spinach, cabbage, chlorella, spirulena, beans, and lentils. Be creative and allow your body to enjoy the nourishment from these living foods