- Gen Alpha most likely to break out in rashes and behavioural issues – with strawberries the top trigger
- Gen Z can react to coffee and garlic, with bloating and headaches common symptoms
- Boomers react most commonly to pineapple, with IBS a top symptom
A new analysis of 2856 Australians has revealed the top ‘triggering’ foods and the symptoms they cause in each generation. The data, compiled by FoodFit – which has conducted more than 250,000 tests for ‘food incompatibility’ since 1985 – reveals that common foods such as strawberries, garlic, pineapple and even coffee can trigger symptoms such as rashes, fatigue, bloating, headaches and irritable bowel syndrome. FoodFit’s latest indepth analysis has identified the top 10 triggering foods and their associated symptoms for each generation.
Food incompatibility is a lesser-known form of food reactivity. Symptoms flare up when ordinary foods temporarily disrupt an individual’s current cellular or inflammatory state, showing up as bloating, rashes, brain fog and headaches. Unlike allergies, which trigger a blood-based immune response, or intolerances, which stem from enzyme deficiencies, incompatibility aggravates existing imbalances.
And FoodFit’s latest data – where it aggregated 2856 hair sample tests conducted in the 2025 financial year – reveals those imbalances show up differently across the generations. The findings highlight that food incompatibility is inherently bio-compatible and what causes a reaction in one individual may be completely tolerated in another. It’s never a one-size-fits-all outcome.
Each year, FoodFit receives upwards of 5000 symptomatology reports each year from natural health practitioners. Armed with hair (and sometimes saliva) samples, FoodFit tests them against more than 600 whole foods and household products and then guides individuals through a six-month elimination process to reduce inflammation and restore balance. Many foods can be reintroduced once the body resets.
Dennis Hodges, Founder and CEO of FoodFit, says: “Our reports reflect people who had no diagnosed allergies or intolerances, but were suffering unexplained symptoms and underwent FoodFit testing through their naturopath. We aggregated these results to identify a real-world snapshot of how food incompatibility is troubling different age groups.
“A food like strawberries or coffee might be fine for one person but can cause issues in another, depending on their cellular state at the time and life stage. For kids, it could be rashes, a teenager could suffer from unexplained headaches, compared to an older Australian who could be dealing with irritable bowel syndrome.
“We’re not saying strawberries, coffee or garlic are bad foods. We’re saying they may not suit the impacted individual’s system right now. A Boomer’s food incompatibility can look different from a Gen Z’s. That’s because our program works on a bio-compatibility basis. It recognises that every body is different and there is no universal trigger list. Our testing uncovers that – and gives people a roadmap back to balance.”
FoodFit’s analysis found the top 10 symptoms and incompatible foods (after bread and milk) across each generation.
- Gen Alpha (under-12s). FoodFit’s analysis found that the top symptoms in Gen Alpha are skin and behavioural issues. Rashes and eczema top the list (11.6%), with constipation, hyperactivity and sleep issues close behind. Their main food foes? Strawberries (64.7% of this cohort), tomato paste (50.4%) and corn tortillas (46%).
- Gen Z (age 13–28). This generation experiences symptoms linked to poor digestion such as bloating, headaches, diarrhoea and constipation. The foods most likely to cause them are corn tortilla (50.5% of this age group), chlorella (47.4%) and coffee (46.3%).
- Millennials (age 29-44). The ‘cognitive crisis’ generation, where brain fog, tiredness and poor sleep are among the top complaints. These are fuelled by incompatibility with chlorella (48.7% of this cohort), strawberries (43.6%) and garlic (42.9%).
- Gen X (age 45-60). This is where physical deterioration begins – and it’s the first time joint pain makes the top 10 list of symptoms. However, bloating, brain fog and tiredness top the list. These are aggravated by strawberries (50.8% of this age group), tortillas (49.2%) and chlorella (47.5%).
- Boomers (over-60s). Irritable bowel syndrome is the top symptom after bloating, followed by reflux and flatulence. Boomers fare worst with foods often seen as healthy: pineapple (52.9% of this group), garlic (50%) and chlorella (50%) all appear in the top list of incompatibilities.
FoodFit’s Compatibility Program is available exclusively through qualified practitioners and involves testing for 600 foods and household items, plus a six-month guided elimination plan, at a one-off cost of $299.
Top 10 incompatible foods by generation (after bread and milk):
Top 10 symptoms by age group:
About FoodFit
Founded in 1985, FoodFit (originally known as Naturopathic Services) is Australia’s longest-running provider of food reactivity testing and practitioner-led health programs designed to identify and eliminate foods that may be aggravating the body at a cellular level. Unlike allergy or intolerance testing, FoodFit’s approach focuses on supporting the body’s natural healing by temporarily removing incompatible foods and restoring overall balance. On average, 5,000 Australians a year have undertaken the FoodFit Compatibility Program, administered exclusively through trained healthcare practitioners nationwide. Find a practitioner here: https://foodfit.com.au/consultants.