Carbohydrate

Carbohydrate = starch + sugars

Sugars are either monosaccharides, disaccharides or oligosaccharides, depending on the number of sugar molecules in their structure. For example, glucose is a monosaccharide and sucrose is a disaccharide (glucose+fructose). Oligosaccharides are also short-chain (at least three) molecules. Starch is a polysaccharide containing a very large number of glucose molecules.

In the UK food composition tables, carbohydrate is expressesd as monosaccharide equivalents. For product labels (EU), carbohydrate must be expressed as absolute values. Thus, there are differences between carbohydrate (and energy) values on product labels and those used for other purposes. However, the differences are small.

Foods containng carbohydrate influence blood glucose level in different ways, depending on their Glycaemic Index(GI). Click here for further information.

Dietary Fibre

There are two methods used for assessing dietary fibre, these measure different components:

• Englyst Method - non-starch polysaccharides
• AOAC Method - non-starch polysaccharides + resistant starch + lignin

Non-starch polysaccharides = cellulose + non-cellulosic polysaccharides. Forms of non-starch polysaccharides include items known as "soluble fibre" and "insoluble fibre". The fibre content of wholemeal bread is largely insoluble fibre, whereas fibre in fruits snd vegetables is largely soluble fibre. These forms of fibre have different physiological effects. For example, insoluble fibre tends to travel through the gut faster, but has little effect on blood cholesterol. Soluble fibre, on the other hand, may reduce blood cholesterol, but has less effect on gut transit time.

Either Englyst or AOAC fibre can be used for product labelling. Most countries in the EU use the AOAC method and this is the method recommended by the Food Standards Agency (FSA) for product labelling in the UK. The EU Nutrition Labelling Directive was amended in 2008 to include an energy contribution from dietary fibre. Fibre provides 2 kcal/g (8 kJ/g). After October 2012 ALL foods sold in the EU must comply with this amendment.

The Englyst method is used most often in the UK for assessing the adequacy of people's food intake and for menu planning. One reason for this is that both the Dietary Reference Values (DRV) and the legal nutritional standards for school meals are based on the Englyst method.

WISP is used for analysing food intake records, analysing recipes as part of food intake records and doing menu planning. Click here for further information.

For product labelling, the following can be used:

• CARAT
• WISP - Labelling Options Pack

REFERENCES

Dietary Reference Values for Food Energy and Nutrients for the United Kingdom. London: HMSO, 1991

Food Standards Agency. McCance & Widdowson’s The Composition of Foods (6th summary edition). Cambridge: Royal Society of Chemistry, 2002

Nutrition Labelling For Foodstuffs. Council Directive 90/496/EEC, as amended by Commission Directives 2003/120/EC and 2008/100/EC

The Education (Nutritional Standards and Requirements for School Food) (England) Amendment Regulations 2008. Statutory Instrument No 1800

The Nutritional Requirements for Food and Drink in Schools (Scotland) Regulations 2008. Scottish Statutory Instrument No 265