“One man’s food is another man’s poison.”

— Lucretius

Do you experience unexplained bloating, brain fog, low energy or headaches? It’s been estimated that 3 in 4 people have some form of food sensitivity or intolerance that causes unpleasant and unwanted symptoms, whether mild or severe. And these are uniquely individual and largely undiagnosed.

Before we jump in, let’s take a look at the differences between a food allergy, food intolerance, and food sensitivity. Although these three terms are often used interchangeably, their causes are quite different.

A food allergy is a reaction caused by the immune system. It occurs when the body mistakes an ingredient as harmful and defends itself by producing high levels of a type of antibody called immunoglobulin E. It’s estimated that 3-7% of children and about 2% of adults suffer from food allergy. Infants delivered via Cesarean section may have an increased risk of developing food allergies. The most common food allergies are to shellfish, nuts, fish, and eggs.

A food intolerance means you lack the enzymes needed to break down and absorb certain ingredients. For example, those who are lactose-intolerant lack lactase, the enzyme needed to breakdown lactose (the sugar in milk). When lactose is not absorbed, it ferments in the colon and leads to symptoms like gas, bloating, nausea, and intestinal pain.

A food sensitivity is an adverse physical response to a specific ingredient that is triggered by the inability to process or digest a food. This is the most common as we age due to a natural "weakening" of our intestinal lining that leads to tiny leaks. The symptoms might range from digestive problems, such as abdominal pain, bloating, and gas, to other averse physical responses like migraines, headaches, irritable bowel syndrome (IBS), bloating and, brain fog and low energy.

Of all three, it’s easiest to ignore food sensitivity symptoms, or worse — accept them as part of life because of the delay between food ingestion and response times. Food sensitivity responses can take anywhere from 24 to 72 hours to appear – yes, up to 3 days later!

That means the random bloating, brain fog, low energy or headaches you experienced on a Tuesday might not be so random after all… that quesadilla you ate on Saturday night may have been the culprit. Oof!

Luckily, with growing awareness of food sensitivities, it’s easier to begin the process of identifying which foods may be connected to an unwanted symptom you are experiencing. The first step is to identify the trigger foods. You may have a good idea which foods your body disagrees with, but your sensitivity also could be caused by specific food combinations or even certain amounts. Pay close attention to the way your body reacts and keep a concise food journal that’s specific to what you're eating, when you’re eating, and how you're feeling.

Note any and all symptoms you experience. Common symptoms include:

Gas
Bloating
Abdominal cramping / knots
Stomachache
Constipation
Diarrhea
Muscle pain / stiffness
Joint pain
Nausea / upset stomach
Indigestion / acid reflux
Cough
Fatigue
Irritability
Headache / migraine
Congestion in nose or throat
Itching or mucus in throat
Skin reactions

The best approach to manage food sensitivity is to adopt a short-term elimination diet. It works like this: Eliminate a particular food you suspect might be the culprit of your symptoms for about two to four weeks to see if your symptoms recede. Then you reintroduce the food gradually, according to your tolerance, to see if your symptoms reappear.

Elimination diets are trial-and-error, and you may have to try different foods and amounts until you find the right combination. Once you've identified the trigger food (or foods), you can explore the best solution for moving forward. In many cases, reducing or completely eliminating symptoms can be achieved by adjusting portions, changing eating habits — like when, and how fast, you eat—or switching out the food entirely.

And let me remind you, there is no one-size-fits-all. Everybody (and every BODY) responds to food in different ways. Let go of dieting dogma and food trends, and instead, tune into how your body responds without judgement or expectation, just observation. This is not about seeking perfection, it's about building self-awareness and learning from your body's cues. When you slow down and tune in, you can decode the messages your body is sending to you, loud and soft.

Remember, you know your body and yourself better than anyone else. If you think you might have a food allergy, intolerance, or sensitivity, talk with your health care provider. Understanding your unique body will put you in the driver's seat of your own health, and how you feel each day.