Sales of gluten-free foods have nearly tripled in recent years, as more people become convinced gluten is responsible for a wide range of health problems.

But according to statistics, just a small percentage of the population actually has a medical reason to avoid gluten. And for those who don’t, going gluten-free may do more harm than good.

“Gluten-free foods often have added sugar, fat, and sodium to make them more palatable,” explained Catherine Roberts, Consumer Reports health editor.

Spanish scientists recently looked at the nutritional composition of 654 gluten-free products. They found many breads, pasta and flours contained more fat and calories and much less protein than products with gluten.

Whole grains also provide important vitamins, minerals, and other nutrients which protect against cancer, heart disease, and type 2 diabetes.

And if the gluten-free foods are made with rice flour, as many are, research shows you could end up ingesting worrisome amounts of arsenic and mercury.

"When you're at the grocery store, rather than looking at processed food labels that sort of scream out, ‘Hey - I'm healthy,' you know, really try and look for the foods that are fresh, whole, brightly coloured and minimally processed. You really can' t go wrong."

But for those who do need a gluten-free diet, you can still get the health benefits of whole grains such as quinoa, buckwheat and amaranth. They are gluten-free and full of fibre, vitamins and minerals.