More people are being diagnosed with food intolerances, and many may have one without knowing it. Symptoms can be mild or strong and are often blamed on something else. If you regularly feel unwell after eating, it could be a sign of a food intolerance.
Is a food intolerance the same as a food allergy?
No. A food allergy can be serious and sometimes life-threatening because it involves an immune reaction that usually happens soon after eating the trigger. A food intolerance is a sensitivity to certain foods or ingredients—like gluten or lactose—and typically causes symptoms such as indigestion, nausea, or tiredness. Intolerance symptoms are uncomfortable but not life-threatening.
How can you tell if it’s a food intolerance?
Start a food diary. Write down everything you eat and note when symptoms appear. Reactions can show up right away or take up to 72 hours, so look for patterns over time. Be patient and thorough—this detective work often pays off. Also, don’t assume a whole product is the problem; it may be a specific ingredient inside it.
Try removing suspected foods
If you think certain foods are causing issues, stop eating them for a while. Build meals around foods that don’t cause problems for two weeks—this helps your body reset. Keep in mind reactions can be immediate or take a few days. You might feel tired or have headaches at first; drink plenty of water. If your food diary didn’t help, try cutting common triggers like milk, fish, eggs, tree nuts, soy, and wheat. You may also want to avoid alcohol and coffee for a time, as they can affect the gut.
Reintroduce foods slowly
After two weeks, add one food back into your diet and watch for symptoms for two to three days. If you’re fine, try another food. If a food causes symptoms, remove it again and wait about three days before testing a different one.
Watch foods you eat often
If symptoms happen regularly, they’re likely linked to something you eat frequently. You don’t always have to give a food up forever. Some people remove it, let their body calm down, and then reintroduce smaller amounts after about three months.
Be careful about cutting out whole food groups
Quickly removing entire groups can lead to nutrient gaps and affect your gut microbiome. If you cut out milk, for example, replace its nutrients with other foods. Some people find the cause quickly; others take longer or never find a clear trigger. If you can’t get answers, see a qualified dietitian for help.
Stephen Marshall is Director and CEO of Be Basic in Meridian, Idaho, with a background in marketing and financial services. His work has appeared in publications such as Tweak Your Biz, Mobile Business Insights, Social Nomics, Small Biz Club, Energy Central, DZone, BizCommunity, BlogHer, and more.