A spokesperson for Diabetes UK told NutraIngredients.com: “Diabetic foods tend to be quite expensive and are not that good for you.” He added that consumers may be lulled into a false sense of security that they are eating healthily.

Advice on the charity's website holds that although such foods use a bulk sweetener like sorbitol or fructose in place of sugar, which allows them to be labelled as ‘sugar-free', their nutritional content, such as fat and calories, is similar to ordinary confectionery foods and therefore still raise blood glucose levels in the same way.

As the technology behind functional foods become more advanced, a new category of foods containing ingredients is emerging specifically designed to help sufferers manage their condition and to help at-risk people reduce the likelihood of developing it.

For instance, US company Nutrition 21 has conducted research into the benefits of its chromium picolinate supplement and is actively pursing its use in foods.

DSM Nutritional Products is also understood to be in the latter stages of developing an ingredient for diabetes prevention.

Other recent research has investigated the potential of fibre-enriched bread to help manage insulin sensitivity and protect against type-2 diabetes, and studies involving supplementation with cinnamon extract have also yielded positive results for blood-glucose levels.

At present, no guidance exists, either at a European or UK level, on products labelled as “suitable for people with diabetes”.

A spokesperson for the Co-Op said that the supermarket still have other products on its shelves that are suitable for people with diabetes – as well as those on a conventional diet. It does not currently stock functional foods for diabetics, and would consult with Diabetes UK before making a decision in this area.

The current advice from Diabetes UK is that blood glucose levels are best managed by adhering to a healthy balanced diet. The spokesperson said that the occasional mainstream treat, such as a chocolate bar, would not be problematic when consumed in this context – but everyday indulgence is not advisable.

As for possible future endorsement of functional foods, the organisation would take a view on the basis of evidence available.

For now, its care advice is founded on guidelines published in Diabetic Medicine (2003; 20: 786-807, The implementation of nutritional advice for people with diabetes. Based on this, it does not advocate specific vitamins or minerals for diabetics unless a clinical need dictates.

But a care manager for the organization said: “We review it very regularly, as we want the best care for people with diabetes.”