The type of carbohydrates you eat before a workout may influence how much fat you burn during your exercise session, according to new research published in the May issue of the Journal of Nutrition and on HealthDay. The study found that women who ate a breakfast rich in carbohydrates that do not cause a spike in blood sugar - such as muesli, yoghurt or skim milk - burned 50 per cent more fat during a post-breakfast workout than did those who ate a breakfast rich in the kind of carbohydrates known to make blood sugar rise sharply, such as cornflakes and white bread.

Carbs that cause a sharp blood sugar rise are known as high-glycaemic index carbs, while those that don't are called low-glycaemic index carbs. While other researchers have also found that a low-glycaemic menu is beneficial to fat burning, the new study has some unique points, noted lead author Emma Stevenson, a senior lecturer at Northumbria University, Newcastle Upon Tyne, in the United Kingdom. She conducted the study while at the University of Nottingham.

High- and low-glycaemic indices

Most of the research in the effects of the glycaemic load of pre-exercise feeding has been carried out in male subjects, Stevenson said. Most of it also has focused on endurance athletes, which doesn't describe the bulk of the population.

The new study included eight women of a typical healthy weight who averaged 24 years of age. On two different occasions, the women ate either a high- or low-glycaemic index breakfast, then walked on a treadmill for 60 minutes three hours later. Stevenson's group drew blood samples before the breakfast and also during and after the exercise to measure parameters such as free fatty acids, which are a marker for fat burning. The average amount of fat oxidised during the exercise was 7.4 grams after the low-glycaemic meal but just 3.7 grams the higher glycaemic index meal, a nearly 50 per cent difference.

Researchers said that high-glycaemic index carbs are known to spur a big spike in blood sugar, and believe that a meal rich in low-glycaemic carbs, which elicit a lower blood-sugar response, may boost the body's use of body fat for burning rather than for blood sugar. Each breakfast totalled about 265 calories, but the low-glycaemic meal had more fibre, the team noted. To burn more fat, researchers say focus on the low-glycaemic foods, such as whole grains, porridge, wholegrain cereals, soy and linseed bread.

- HealthDay.com

Visit the Creators Syndicate website at www.creators.com.