Rising levels of obesity and the associated health risks, continues to be our biggest public health challenge of the 21st century. Public health strategies have not yet been successful in reversing the obesity trend. Therefore, simple strategies to regulate food intake and facilitate the maintenance of a healthy weight have increasingly become an area of interest and research. Studies have shown that consumption of low-GI carbohydrates prolong satiety, reducing subsequent food intake.(Reference Warren, Henry and Simonite1) This has led to the proposal that low-GI carbohydrates could be used in the regulation of food intake to induce weight loss in the overweight and obese.(Reference Esfahani, Wong and Mirrahimi2) However, the findings are not always consistent(Reference Esfahani, Wong and Mirrahimi3) and the current evidence is conflicting.
This pilot study aimed to compare the impact of a low glycaemic index breakfast with a high glycaemic index (GI) breakfast on satiety over 3 hours and subsequent food intake over the rest of the day. 10 healthy female subjects (18–65yrs) took part in this cross over study. Subjects were randomly allocated to either the high or low GI breakfast on test day one, and the alternative breakfast on test day two. Breakfasts were matched as closely as possible in macronutrient and energy content. Each ingredient was assigned a GI using the international table of glycaemic index and glycaemic load values.(Reference Foster-Powell, Holt and Brand-Miller4) Ingredients (cornflakes/porridge, white bread/rye bread, jam, orange juice/skimmed milk) were selected to result in either a high or low GI meal. Satiety was self reported, using a visual analogue scale and dietary intake was assessed using a self reported 24 hour food diary. Paired sample t-test was used to compare mean values.
The low GI breakfast elicited a significantly higher level of satiety over 3 hours and a significantly reduced dietary intake than the high GI breakfast over 24 hours. Although this was a short term pilot study, the results indicated that adherence to a low GI breakfast may be helpful for overweight individuals wishing to reduce their energy intake. However, longer term, larger studies are required to confirm these findings.
