I've always wondered whether some of the health problems I have - headaches, sinus problems, and skin problems - are related to what I eat. In researching the connection between diet and health, I came across something known as the food elimination diet.

The concept behind the elimination diet is simple: you cut out every food that could possibly cause a reaction. This includes peanuts, tree nuts, fish, shellfish, dairy, eggs, soy and wheat, which cause about 90 percent of food allergies.

This didn't seem to me like a typical fad diet - it seemed more scientific. So I embarked on the adventure of turning myself into a nutritional guinea pig.

Daily diary

Once you've eliminated potentially reactive foods, there's not much left: lean meats such as turkey and lamb, non-gluten grains such as rice and quinoa, fruits except for citrus, and all vegetables except for those in the nightshade family, such as eggplant and potatoes.

It's important to log everything you consume, and note how you feel.

The first few days of my dietary experiment were especially challenging for me, as evident from my diary:

Day 1: I feel like crap. I have a headache, and I'm aching all over.

Day 2: I feel kind of like I'm hungover.

Day 3: I still have aches and pains, and just don't feel that good.

But my condition did gradually improve:

Day 4: I'm actually feeling … okay.

Day 8: I feel pretty much normal. My breathing is clearer, my sinuses are clearer, and the patch of psoriasis on my scalp is gone.

Although most of my symptoms had improved after about a week and a half on the diet, I kept running into challenges. It was hard for me to handle the limitations it imposes. The diet was also costing a lot of time and energy: two to four hours every day for planning, preparing, eating, and cleaning up.

Day 16: I'm totally sick of diet. I just want it to be over.

Since most of my symptoms had improved after about 10 days, I decided to start the "challenge" phase of the elimination diet. That's when you eat a certain type of food for one day, then cut it out again while you monitor your body's reaction. It was exciting to experiment with my own body. Not to mention, I made more than a few realizations:

Day 19: Eating healthy takes a huge investment.

Day 25: Wow, the farmer's market has great produce. It's all organic, and so cheap.

The diet got easier to manage as I reintroduced more items. But after five weeks, I still hadn't found out what might be causing me to react. And Dr. Google wasn't providing the answers I felt I needed - so I consulted a flesh-and-blood expert.

Allergy vs. intolerance?

Peter Strauven, a medical doctor who specializes in nutrition, says that about four percent of the population has a food allergy. Intolerances are more common - but Strauven says people often falsely believe they have a food allergy when in fact they don't.

So what's the difference between an allergy and an intolerance?

Strauven says a food allergy displays a strong, immediate reaction, whereas an intolerance can come and go over time, and usually has a delayed reaction.

"Somebody eats something and after about five minutes, there's some swelling of the mucus membranes in the mouth - that's an allergy," Strauven says.

But a person with a food intolerance might see "some bowel irritations after one or two hours" - though this delay can go up to 20 hours.

While an astounding one-third of adults believe they have a food allergy, about two-thirds of those people probably have an intolerance.

A food allergy is defined as an immune response that specifically involves the immunoglobulin E (IgE) antibody.

These react to proteins in food, such as those in wheat or milk, and identify them as foreign objects that need to be neutralized. The strong immune system response can make a person very sick, or even be deadly if it progresses to anaphylactic shock.

An intolerance on the other hand occurs when a person lacks the enzymes to digest a certain kind of food, such as lactose or gluten. Intolerances aren't deadly, but they can cause a lot of discomfort. An intolerance can involve immunoglobulin G (IgG), which can cause tissue inflammation - and this inflammation can "leak" from a person's gut into their whole system.

This is called "leaky gut syndrome," which is theorized to be behind a number of health conditions, including chronic fatigue syndrome and multiple sclerosis.

Growing problem

Although many people falsely believe they have a food allergy, food allergies and intolerances as a whole are on the rise, Strauven says. He believes the additives and preservatives in food are contributing factors.

"Your body is a certain kind of garbage container. You fill it all your life, and then the top blows off," says Strauven. The immune system is no longer able to isolate the inflammations, he explains, and so your body reacts by developing an allergy or intolerance.

Strauven advises his patients the best way to find out whether they have a food allergy or intolerance is to get a blood - or prick - test. But he also warns that commercial blood tests can produce false positives, resulting in unnecessary dietary restrictions. The elimination diet, says Strauven, is also an effective tool.

Surviving a food intolerance

For Stefanie (not her real name), a woman in her early 40s, a combination of methods helped her resolve chronic health problems related to food intolerance.

After suffering for years from eczema - a condition involving itchy, irritated skin - she first did a blood test that produced a list of some half-dozen food items, including dairy and certain fruits.

She started off by eliminating these from her diet.

And as I did, she at first felt ill.

"After two weeks, I got some strange reaction that was really worse," Irene says. "It felt as if the body was spitting out some poison."

Dr. Strauven confirms you can feel sick at the beginning of the elimination diet because your body is undergoing a detoxification process.

But after about two months, Stefanie says, her skin was clearer than it had been in years.

Stefanie then reintroduced the foods listed in the blood test to see whether they were causing her to react.

"I noticed that the skin on my hand started to itch the day after I drink red wine," she says by way of example.

I wanted to know whether her food allergies constrict her enjoying daily life?

"We live in a country where there's such a great selection of foods," she says. And it's hard for her to resist eating a tasty-looking piece of cheese at times, but the end benefit is clearly worthwhile, she says.

Having come close to the end of my experiment with the elimination diet I have managed to narrow down my own "culprits" - I suspect they include food additives, such as monosodium glutamate, and preservatives such as sulfites in wine.

And as a result of eating whole foods for a month and a half, I've lost weight and feel great.

I have not only survived - but perhaps even thrived - on the elimination diet.