05/08/2014 02:31 pm ET Updated Jul 08, 2014

How 'Going Gluten-Free' Sparked a Bigger Discussion About Food Intolerances

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Over my nearly three decades as an expert, I've witnessed a sea change in the fitness and especially nutrition arenas. Dietary fat as public enemy number one has been replaced with sugar, to which recent studies have not been kind.

One recent large epidemiological study concluded "sugar should be investigated for its role in diabetes pathogenesis apart from its contributions to obesity." Another just-published study found "a significant relationship between added sugar consumption and increased risk for CVD [cardiovascular] mortality."

A Paleo diet, with an emphasis on whole, unprocessed foods, has replaced the fake-food low-fat craze so prevalent even a decade ago. Things are changing for the better.

Then we have the gluten-free fad or revolution, depending on who writes about it. As gluten-free diets become mainstream, experts are finally being forced to acknowledge food intolerances.

My friend Dr. Mark Hyman does a great job succinctly explaining how food intolerances develop. He says:

The problem is that most people ... eat foods they are allergic to several times a day. Meaning every time that food enters the body, the immune system whips itself into a frenzy. But because symptoms are delayed up to 72 hours after eating, a low-grade food allergy can be hard to spot. Without diagnosis or awareness, the damage is repeated over and over, meal after meal. Eventually, inflammation seeps throughout the body, establishing an environment ripe for weight gain and chronic disease.

Despite what Hyman and other well-renowned experts claim, many conventional practitioners refuse to acknowledgement food intolerances, erroneously dismissing them as "fad diets" or claiming a lack of scientific evidence.

Slowly, we're getting studies that prove otherwise. One recent study concluded a gluten-free diet could reduce inflammation and insulin resistance, preventing obesity and metabolic disorders in the bargain.

I've witnessed this myself since I began testing clients for food intolerances. From that testing, I isolated seven foods that most frequently created reactions: Gluten, soy, eggs, dairy, corn, peanuts, sugar, and artificial sweeteners. (I, um, lump those last two together.)

When clients remove these foods, headache, fatigue, and other symptoms disappear. They look and feel better. They finally discover that needle mover to overcome weight loss resistance.

I firmly believe further studies will validate food intolerances, but why wait for science to catch up?

Here's my challenge: Pull the seven highly-reactive foods -- gluten, soy, dairy, eggs, peanuts, corn, sugar, and artificial sweeteners -- for three weeks and see if things don't improve for you.

Instead of depriving yourself, make intelligent lateral shifts. Most are so easy. Swap out wheat wraps for gluten-free rice wraps, unsweetened coconut milk for cow's milk, no-corn quinoa pasta for spaghetti noodles, and so on.

Folks report a new normal when they pull these seven foods. They ditch those last stubborn few pounds disappear. They don't suffer mid-afternoon brain fog or post-meal gastric misery.

I eventually want you to challenge four of these foods -- dairy, gluten, soy, and eggs; one each week -- and see if you can tolerate them. You may discover you can occasionally tolerate an omelet or organic tofu. Or you may learn a particular food must vacate your diet permanently.

Who's with me to taking the challenge? You can do anything for three weeks, and you've got nothing to lose except those frustrating symptoms and that extra weight around your midsection.

Have you ever gone gluten-free or removed any other potential food intolerances? Share your results below.