As a Celiac Disease survivor I cringe whenever I hear the term "fad" used in context with "gluten-free" because calling a gluten-free diet a fad can minimize the pain and suffering so many of us living with a gluten-related disorder experiences, and also feeds the notion that avoiding gluten is a trendy choice rather than a necessity.
There are many different ways someone can react to gluten-containing grains, but first, let's define what type of gluten we're talking about.
You might be surprised to learn that there are storage proteins like gluten in corn, rice, and oats, and for some people those grains may be problematic for different reasons, but for the purpose of this conversation, those are not the types of gluten that have been shown to be the most problematic in gluten-related disorders.
There is a specific family of gluten proteins contained in wheat, barley, rye, spelt, couscous, and other less common, grains including ancient grains, that have been shown to be immunogenic (able to produce an immune reaction) and contribute to many of the problems associated with gluten-related disorders. 
Currently, 3 types of Gluten-related Disorders have been identified:
The autoimmune condition, Celiac Disease
Non-Celiac Gluten Sensitivity (NCGS)
Non-Celiac Gluten Sensitivity has recently been gaining the attention of medical researchers, so there is new and emerging information that we will continue to learn about this as time goes on.
It’s currently estimated that at least 6% - 28% of the population suffers from some form of Non-Celiac Gluten Sensitivity, but in reality, experts don't yet know how extensive this condition actually is. 
There are also many different ways someone can react to foods that contain the problematic gluten including, but not limited to: 
An immune system reaction to one or more of the many immunogenic proteins found in gluten.
Intolerance of the FODMAP carbohydrates in the gluten containing grain, typically due to dysbiosis of the gut microbiota.
A reaction to the glyphosate sprayed on conventionally grown wheat.
Complications due to increased intestinal permeability, which specific gliadin proteins in gluten have been demonstrated to cause by an up-regulation in Zonulin signaling.
And, there are other components of wheat that someone may react to that does not involve the gluten part of the grain. 
Taking all of this into consideration, I think it’s important to consider that tolerability of gluten-containing grains, and of wheat specifically, is a very complex issue, and whether or not avoiding gluten is right for someone, is not a simple question to answer.
Fortunately, lab testing is getting better at helping us understand how our body is reacting to the peptides of gluten, and various components of wheat, especially from an immunologic perspective.
And, this advanced lab testing is helping us determine if a life-long avoidance of gluten is necessary, and who it might be necessary for. Feel free to contact me here if you'd like to learn more about advanced testing for gluten sensitivity.
Back to gluten-free foods -- I actually love that an awareness of gluten over the past several years has reached the mainstream. It allows us to have a good conversation about how these foods may, or may not, be affecting our health.
An increased awareness of the multitude of problems people can experience when they consume gluten-containing foods has also prompted food manufacturers to create more gluten-free substitutes, which as someone who needs to avoid gluten 100%, I am grateful for because I am able to enjoy a piece of gluten-free bread or dessert on occasion.
I definitely agree that many, if not most, "gluten-free" substitutes are not healthy. And, we could probably find examples of unhealthy food choices technically allowed in just about every popular diet.
So, I think most of us can agree that just because something is gluten-free doesn't mean it's healthy.
But on the flip side, I'd like to suggest that a gluten-free diet isn't inherently bad as long as the proper food choices are being made.
The good news is that there are many health-oriented food manufacturers that are trying to make gluten-free substitutes more nutritious, and I really appreciate that effort.
I believe it is very important to determine the most healthful diet for each of us personally. And, I also believe it is absolutely possible to live an extremely healthy gluten-free life!
We just need to learn how to choose foods that are naturally free of gluten instead of relying on substituting what we were eating with a gluten-free alternative. This means, learning how to choose a variety of real, whole, nutrient dense foods appropriate for our personal bio-individuality.
I hope you found this helpful. You are welcome to contact me here with any questions or comments you have!
Jaime Ward, INHC, CGP, CBIN provides Functional & Integrative Nutrition Health Coaching for Women with Autoimmunity.
Jaime is Board Certified by the American Association of Drugless Practitioners, Certified in BioIndividual Nutrition, a Certified Gluten Practitioner, and currently pursuing a Master of Science degree in Nutrition with a focus on Functional Medicine from The University of Bridgeport.
Jaime is also a speaker, a writer, a busy mom, and a Celiac Survivor. Jaime coaches with a Christian heart filled with lots of love, support and compassion.
For more information about how Jaime can help you, click here.
 Balakireva, A. V., & Zamyatnin, A. A. (2016). Properties of Gluten Intolerance: GlutenStructure, Evolution, Pathogenicity and Detoxification Capabilities. Nutrients, 8(10), 644. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5084031/