FOOD manufacturers and government agencies have consistently misled consumers over many years about the number of calories contained in food, nutritional experts said today.
Calorie-counting people trying to lose weight do not realise that the official system for assessing the caloric value of food is seriously flawed and incapable of providing accurate estimates of the amount of energy in a product, they said.
Food companies for instance do not take into account the caloric value of fibre in food with the effect that some high-fibre foods which are sold as low in calories may actually contain, in the extreme, up to 25 per cent more calories than the label suggests.
It means that some high-fibre foods targeted at people on a diet are actually more fattening than people are led to believe, said Geoffrey Livesey, an independent nutritionist based in Britain who has advised the UN’s Food and Agriculture Organisation.
“The problem is the system did not consider fibre, but it has a big impact on the variance of energy content in food. What the old system gave us is a very general calorific value,” Dr Livesey said.
“In Britain, we have not assigned a value for fibre, so calorie counts have normally been lower - on average around five per cent of energy in food is fibre,” Dr Livesey told the American Association for the Advancement of Science meeting in Boston.
“So consumers have been eating more calories than they thought they were, particularly if the food was high-fibre. When people eat muesli, it is a healthy food but they are often putting on lots of weight,” he told the meeting.
Consumers have been unknowingly consuming extra calorie in high-fibre food for decades because the system for assessing calories goes back to the 1970s and even earlier. It means that if people follow the daily recommended intake of 18 grams of fibre, they could be consuming more than 250 extra calories each week without realising it, Dr Livesey said.
It is not only the presence of fibre that has upset the calorie estimates. Scientists have known for many years that the calorie counts on food labels do not take into account the energy expended by the body in eating and digesting a particular type of food, said Richard Wrangham of Harvard University.
Independent News Service