"She just won't eat, I've tried everything", "He's a fussy eater!" - "it's the terrible twos!" We all know kids can be a handful - especially at mealtimes. But what if their fussy, possibly unruly behaviour signals a medical problem? Could it be that what we think is good for them, actually isn't?

I regularly meet parents who desperately try to decipher their child's cries, fussy habits and mood swings - with no idea of what's wrong. Often children will either refuse to eat or gag on certain foods for no apparent reason.

Let's take lactose intolerance for instance. This is more common that you think. In fact Primary lactase deficiency, the most common cause of lactose intolerance, is caused by the absence of lactase and affects 70% of the world's population. The prevalence and age of onset vary by ethnicity; it is particularly common in Hispanic, Black, Asian, American Indian, and Ashkenazi Jewish people. Primary lactose intolerance develops in childhood yet is often overlooked.

Babies are born with higher levels of lactase, the enzyme that helps break down milk. This enzyme begins to decline at about the age of two-three years old, which is often when children start to have symptoms.

Common conditions like eczema and migraine have been linked to what we eat. Yet despite a mountain of evidence linking common ailments with diet, very few children are actually tested to find out what their "trigger" foods are. As a result, many parents plough on for years and years, confused about where they're going wrong.

Occasionally, the penny drops: "Ah! She's allergic to that!" - but the fact is genuine food allergy is rare, and, like a Botticelli painting, the picture is a lot more complex than it might first appear.

Let's not get confused. A true food allergy actually involves a potentially life threatening response to food by the immune system. It can cause classic symptoms such as difficulty breathing, wheezing, rash and itching. It involves IgE antibodies being produced and around 2% of the population (and 8% of children under the age of three) are affected.

However there are many other reactions to food including delayed IgG food allergy or intolerance as well as intolerances caused by a lack of enzymes needed to deal with a particular food or protein. The symptoms can be wide-ranging - making the tough job of parenting even tougher! If your tot has a delayed food reaction or an intolerance, it could show up as a bad case of wind, diarrhoea, abdominal cramps, upset tummy, bloating, irritability, crying, or a refusal/reluctance to eat certain foods.

"So how am I supposed to know the difference?!" I hear you cry. Well, you're not. That's a specialist's job. But one thing parents are brilliant at, is knowing when something is wrong - and that's your cue to get help.

Food intolerance is actually really common. Allergy UK estimates that up to 45% of people in the UK develop food intolerance, and the incidence of diagnosis is increasing in the younger population.

Scientists fear that leaving countless children undiagnosed will lead to problems related to their health, learning and development. Their performance at school can drop, as well as their morale. Amazing that something as simple as an intolerance test can save them from years of food related fret. Food for thought, isn't it? (Sensitivity-related illness: The escalating pandemic of allergy, food intolerance and chemical sensitivity Stephan J Genius 2010)

There are a number of ways to identify your family's triggers, one that I recently came across is YorkTest, Europe's leading provider of food intolerance programs with over 30 years experience. YorkTest food intolerance tests can uncover potential food triggers, allowing people to quickly and easily modify their diets and making the process of dietary change far less daunting for busy mums.

Do you have a Food Allergy or Intolerance?
Many people use the term 'food allergy' to describe all reactions to food but this is not accurate. A true food allergy refers to a response of the immune system that is triggered when a particular food is eaten. Antibodies (known as IgE) are produced resulting in the production of inflammatory chemicals like histamine. Immediate symptoms such as hives, rashes, vomiting, wheezing and in some cases anaphylaxis can develop.

But most types of food reactions are slower acting - often referred to as IgG food intolerances because they involve the production of IgG antibodies. Symptoms may occur anything from two hours to 2 days after the food has been eaten which can make it difficult to figure out which foods are the culprits. The most common allergens are wheat, gluten, dairy, eggs, nuts, soy and shellfish but you can react to anything. To add to the confusion there are also other intolerances such as intolerances to lactose (found in dairy), fructose, phenols and salicylates.

Common Symptoms of Food Allergies/Intolerance
These are the most common symptoms associated with a food allergy/intolerance
• Fatigue
• Bloating, weight gain, water retention
• Diarrhoea, constipation, irritable bowel syndrome
• Abdominal pain
• Vomiting, nausea
• Nasal congestion, running nose, sinus problems
• Migraines, headaches
• Rashes, itches, hives
• Asthma, shortness of breath
• Aches and pains in joints
• Mood swings, depression

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