Food intolerance in teenagers
When teens (or social media) decide a food is 'the problem'. How to investigate properly and avoid unnecessary restriction.
The
TikTok and Instagram drive a lot of self-diagnosed 'intolerances' in teens. Gluten, dairy, FODMAPs, 'inflammatory foods', histamine, lectins. Some of these are real clinical entities. Many of them, as presented on social media, aren't. The volume of unqualified nutrition advice targeting teenagers online is genuinely problematic, and restriction-as-identity is something to be mindful of, as it can sometimes be associated with the development of disordered eating patterns.
I'm not dismissive of teens who think they have an intolerance. Symptoms are real and deserve investigation. But the route to answers matters. Self-diagnosing from social media and cutting out multiple food groups without investigation isn't harmless: it can cause nutritional deficiencies, eating anxiety, social isolation around food, and missed real diagnoses. A teen who goes gluten-free because of TikTok before being tested for coeliac disease has now made it much harder to ever get a clear diagnosis, as Coeliac UK warns.
In my consultations, I take the symptoms seriously, investigate them properly, and give the teen a clear answer about what's actually going on. Sometimes it is an intolerance. Sometimes it's IBS. Sometimes the symptoms have a different cause entirely. The point is to find out, not to guess.
How food intolerance is
Genuine food intolerance is investigated through a structured elimination and reintroduction process guided by a dietitian. It gives you a real answer, done properly.
Before any elimination, relevant medical investigations should happen first. NICE recommends coeliac serology before cutting out gluten. Consideration of inflammatory bowel disease, infections, or other causes of gut symptoms. Jumping straight to dietary elimination without ruling out medical causes first is poor practice, and it's a common pattern in teens who have been self-managing.
Why 'intolerance tests'
The IgG-based food intolerance tests sold online and in some pharmacies have no good evidence base. The British Dietetic Association, the British Society for Allergy and Clinical Immunology, and major allergy bodies worldwide do not recommend them. They are expensive and they commonly produce false positives that lead to unnecessary dietary restriction.
Hair analysis, kinesiology, VEGA testing, and similar alternative approaches have even less validity. I understand the appeal of a simple test that tells you exactly what to avoid, but these tests don't deliver reliable results. A properly conducted elimination and reintroduction under dietetic guidance is the evidence-based approach, and it's the one that gives you an answer you can trust.
If your teen has already had one of these tests and is now avoiding multiple foods, I'd strongly recommend a consultation to review whether those restrictions are actually necessary. In many cases they aren't, and the restriction is causing more problems than the original symptoms.
Common intolerances in
Lactose intolerance is the most common genuine intolerance in teens. Lactase enzyme activity naturally decreases during late childhood and adolescence in a significant proportion of the population. Symptoms include bloating, gas, abdominal pain, and diarrhoea after consuming lactose-containing dairy. Importantly, most people with lactose intolerance can tolerate some lactose, so complete dairy avoidance is usually unnecessary.
Non-coeliac gluten sensitivity exists but is less well-defined and less common than social media would suggest. It's a diagnosis of exclusion: coeliac disease and wheat allergy must be ruled out first, then a structured trial confirms or refutes it. FODMAPs can be relevant for teens with IBS-type symptoms, but the low-FODMAP diet is a structured, time-limited investigation tool, not a lifestyle. Done without guidance, it often leads to unnecessary long-term restriction.
Common questions
A clear plan,
built around your little one.
All consultations are online and you can self-refer directly. You'll receive a written plan after every appointment.
Thorough assessment & plan
Your first appointment is 60 minutes. It includes a full clinical and dietetic assessment, and you'll receive an agreed, written plan to take away.
Review & adjust
Follow-ups are 30 minutes. We review the plan, problem-solve anything that's come up, and adjust guidance as your child progresses.
Currently self-pay only. All fees are VAT-exempt as registered healthcare services. I provide receipts with my HCPC registration details which you can submit to your insurer.